Index by title

Shepard Test Stand Assembly v1.1

See the assembly instructions here

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Assembly Instructions v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Mechanical System

The assembly of the Mechanical System consists of four main sub-assemblies (shown in Figure 1 below):
  1. The motor mount (a modified Estes D & E Engine Mount Kit)
  2. The motor mount bracket
  3. The main structure
  4. The back plate

Figure 1 - Shepard Mechanical Components

Notes

Motor Mount

Assembly of the motor mount follows the instructions supplied with the Estes D & E Engine Mount Kit with a few small exceptions which are required to accomodate the t-connector (MM06) used to vent the ejection charge.

  1. Take the mount tube (MM01) and mark one end as the front [where the motor will be inserted] and the other as the rear [where the t-connector (MM06) will be attached]
  2. Test fit the t-connector (MM06) in the mount tube (MM01) by inserting it approximately 1/4" into the mount tube (MM01) and then remove it; the fit will be tight, and may even require a slight stretching of the mount tube (MM01)
  3. Make a mark 1/4" from one end of the red engine block (MM04)
  4. Cut the red engine block (MM04) at the 1/4" line from the previous step, keeping the larger section as the final engine block (see Figure 2)
    Figure 2 - Modified Engine Block (top) vs Original Engine Block (bottom)
  5. Follow Step 1 in the Estes D & E Engine Mount Kit instructions
    1. Step 1.A - Make a mark on the mount tube (MM01) 1" from the rear, and make another mark 5/8" from the front [this second mark should be offset along the circumference of the mount tube (MM01) slightly]
    2. Step 1.B - Cut a 1/8" wide slit at the mark 1" from the rear of the mount tube (MM01); insert the engine hook (MM05) into the slit (see Figure 3)
      Figure 3 - Engine hook inserted into mount tube
    3. Step 1.C - Apply wood glue to the outside of engine block (MM06) and the inside of the inside of the rear section of the mount tube (MM01) making sure to completely coat the inside of the mount tube (MM01) up to where the engine hook (MM05) is inserted; Slide the engine block (MM06) into the rear of the mount tube (MM01) until it rests agains the engine hook (MM05); be sure to smooth any excess glue in the mount tube (MM01) to create a smooth water tight surface (see Figure 4)
      Figure 4 - Engine block inserted into mount tube
  6. Follow Step 2 in the Estes D & E Engine Mount Kit instructions - Apply a bead of wood glue around the mount tube (MM01) just to the rear of the mark 5/8" from the front and then slide the engine retainer ring (MM02) onto the the mount tube (MM01) from the front of the mount tube (MM01) until the engine retainer ring (MM02) is just past the 5/8" mark (see Figure 5)
    Figure 5 - Engine retainer ring mounted
  7. Allow the assembly to dry overnight
  8. Apply a bead of multi-surface glue to the edge of the base end of the t-connector (MM06)
  9. Insert the t-connector (MM06) into the rear of the mount tube (MM01) (see Figure 6)
    Figure 6 - Completed motor mount
  10. Allow the motor mount to dry over night

Motor Mount Bracket

  1. Prepare the plate (MMB01)
    1. Drill the four 1/4" through holes for the zip ties (MMB04) (see Figure 7)
      Figure 7 - MMB01 with zip tie holes highlighted
    2. Drill and counterbore the two 3/32" through holes for the machine screws (see Figure 8)
      Figure 8 - MMB01 with machine screw holes highlighted
    3. Create the two 1/4" dados on the bottom of the plate (MMB01) to provide space for the zip ties (MMB04); this can be done on a table saw with either a dado blade or with multiple passes using a standard 1/8" wide blade (see Figure 9)
      Figure 9 - MMB01 with dados highlighted
  2. Clamp the block (MMB02) to the rear edge of the plate (MMB01) (see Figure 10)
    Figure 10 - Block clamped to plate
  3. Drill pilot holes for the two 1-1/2" drywall screws
  4. Attach the block (MMB02) to the plate (MMB01) using two 1-1/2" drywall screws, making sure to leave approximately 1/8" of the rear screw exposed

Rail Shield

  1. Cut out the Rail Shield (RS03) from thin sheet metal (such as duct work metal)
  2. Fold down the long sides of the Rail Shield (RS03) per the dimensions listed in the CAD drawings; this will give the Rail Shield the required regidity
  3. Drill two mounting holes through the Rail Shield (RS03) per the CAD drawings

Main Structure

Figure 11 - Exploded Assembly View

  1. Assemble the Test Stand Base; Note: it is significantly easier to assemble the Test Stand Base using the concrete block (TSBa05) as a stand/jig
    1. Place the top (TSBa02) on the concrete block (TSBa05) so that the rear edge is flush with the concrete block (TSBa05)
    2. Place the two sides (TSBa01) along the edge of the concrete block (TSBa05) so the front edges of the sides (TSBa01) are flush with the front of the top (TSBA02)
    3. Clamp the sides (TSBa01) to the top (TSBa02)
    4. Drill pilot holes through the sides (TSBa01) into the top (TSBa02) [3 on each side], and use 2-1/2" dry wall screws (TSBa04) to attach the sides (TSBa01) to the top (TSBa02); be sure to remove the clamps
    5. Place the front (TSBa03) under the top so it rests against the concrete block (TSBa05)
    6. Drill pilot holes through the sides (TSBa01) [1 each side] and the top (TSBa02) [2 holes] into the front (TSBa03), and use 2-1/2" dry wall screws (TSBa04) to attach the front (TSBa03)
  2. Attach the Test Section Beam
    1. Remove the Test Stand Base from the concrete block (TSBa05)
    2. Draw a line down the centerline of the long axis of the top (TSBa02)
    3. Place and clamp the beam (TSBe01) along the line on the top (TSBa02)
    4. Turn the Test Stand Base on its side and drill 3 pilot holes through the top (TSBa02) and into the beam (TSBe01), and use the 2-1/2" dry wall screws (TSBe02) to attach the beam (TSBe01) to the top (TSBa02); be sure to remove the clamps
  3. Prepare the Back Plate
    1. Drill the 3/8" pass-through hole in the back plate (BP01)
    2. Place the Test Stand Base back on the concrete block (TSBa05)
    3. Place the back plate (BP01) against the back of the Test Stand Base [it should fit between the sides and rest against the concrete block (TSBa05) and the beam (TSBe01)]
    4. Drill 2 pilot holes through each side (TSBa01) into the back plate (BP01)
    5. Drill 1 pilot hole through the back plate (BP01) into the beam (TSBe01)
    6. Note: Do not attach the back plate (BP01) yet.
  4. Treat the test stand components with heat resistant paint
    1. In a well ventilated area, lay out all of the wooden components and apply two coats of heat resistent primer (see Figure 12)
      Figure 12 - Priming Shepard components
    2. Allow primer to dry per manufacture's instructions
    3. Apply two coats of heat resistent paint (see Figure 13)
      Figure 13 - Painting Shepard components
    4. Allow paint to dry per manufacturer's instructions

Final Assembly

  1. Insert the two zip ties (MMB04) into the Motor Mount Bracket (see Figure 14)
    Figure 14 - Zip tie placement
  2. Use the metal screws (MMB03) to attach the Motor Mount Bracket to the end of the drawer slide (RS01) (see Figure 15)
    Figure 15 - Motor Mount Bracket attached to Drawer Slide
  3. Use the metal screws (MMB03) to attach the Rail Shield (RS03) to the drawer slide (RS01) next to the Motor Mount Bracket. (not shown)
  4. Attach the drawer slide (RS01) to the beam (TSBe01) using 1-1/2" drywall screws (RS02) (see Figure 16)
    Figure 16 - Drawer Slide attached to Beam
  5. Place Motor Mount on Motor Mount Bracket and close the zip ties (MMB04) snuggly; note, be sure to have a motor in the motor mount to prevent the zip ties from crushing the Motor Mount (see Figure 17)
    Figure 17 - Attaching the Motor Mount
  6. Trim the excess portion of the zip ties (MMB04) (see Figure 18)
    Figure 18 - Trimming zip ties
  7. Place the Back Plate in position and attach it to the Test Stand Base with 2-1/2" drywall screws (BP03) (see Figure 19)
    Figure 19 - Attaching the Back Plate
  8. Attach the 1-1/2" dry wall screw (BP04) to the Back Plate just above the through hole leaving approximately 1/2" exposed; this screw is used to hang the small pulley (BP02)
  9. Use thin double-sided tape to attach the contact pad (MMB05) to the side of the motor mount block (MMB02) facing the back plate (BP01); note, be sure to align the contact pad with the Force Sensing Resistor mounting specified below

This completes the Mechanical System assembly process.

Data Acquisition (DAQ) System

The assembly of the DAQ system consists of three main sub-assemblies:
  1. MAX31855 Thermocouple Amplifier Breakout Board
  2. Force Sensing Resistor (FSR) cable system
  3. Arduino ProtoShield

MAX31855 Thermocouple Amplifier Breakout Board

Force Sensing Resistor (FSR) cable system

Arduino ProtoShield

Components were soldered onto the ProtoShield in the configuration shown in the images below. Note that in the bottom view, the ProtoShield has been flipped vertically towards the bottom of the picture. This allows you to orient yourself so that you can follow the traces. For higher resolution images to aid in assembly, check the Shepard_v1.0_DAQ_Assembly_Images.zip file here

Figure 20 - Top View of the ProtoShield

  1. The MAX 31855 breakout board has the correct header pin spacing to fit the holes on the ProtoShield, so it was inserted directly. Note that the capacitor that is included with the K type thermocouple when purchased is being used. The thermocouple's reading had too much noise in it otherwise.
  2. The red and green wires used were breadboard prototyping jumpers from Radio Shack. Left over Ethernet cable wires can be used as well.
  3. The resistor was soldered directly to the ProtoShield, but care should be taken that the leads of the resistor do not short any of the connections on the board.
  4. A 14 pin DIP socket was used for the TLV2374 for multiple reasons including prevention of overheating of the IC during soldering, and ease of replacement in the event of damage due to a wiring mistake.
  5. A smaller screw terminal block for the FSR leads (left side) would have ideal, but the larger block pictured was all that was available at the time of assembly. The pins are spaced more widely on the block and thus the positioning was dictated by the spacing of the holes on the ProtoShield.
  6. Notice that even though the two green jumper wires disappear under the MAX 31855 breakout board in the image, they have been labeled with what pins they go from/to.

Figure 21 - Bottom View of the ProtoShield

  1. If you view the high resolution version of this image from the Shepard_v1.0_DAQ_Assembly_Images.zip file here , you'll notice that several solder bridges have been made to connect different points. Use the schematic diagram found in the Shepard_v1.0_DAQ.zip file here to give you a more complete view of what's being bridged.
  2. The solder bridges are made by laying short lengths of stripped solid wire against the pins (or in the holes) and then soldering them.
  3. Figure 22 labels what the corresponding top side connections are for most of the solder joints.

Figure 22 - Bottom View of ProtoShield With Landmark Connections

  1. The solder positions where the green and white/green wires are coming off the board is the location of the Force Sensing Resistor (FSR) screw terminal.

Assembly Instructions v1.0

This document has been relinked to the Initial Questions document here as part of our versioning system update.

Mechanical System

The assembly of the Mechanical System consists of four main sub-assemblies (shown in Figure 1 below):
  1. The motor mount (a modified Estes D & E Engine Mount Kit)
  2. The motor mount bracket
  3. The main structure
  4. The back plate

Figure 1 - Shepard Mechanical Components

Notes

Motor Mount

Assembly of the motor mount follows the instructions supplied with the Estes D & E Engine Mount Kit with a few small exceptions which are required to accomodate the t-connector (MM06) used to vent the ejection charge.

  1. Take the mount tube (MM01) and mark one end as the front [where the motor will be inserted] and the other as the rear [where the t-connector (MM06) will be attached]
  2. Test fit the t-connector (MM06) in the mount tube (MM01) by inserting it approximately 1/4" into the mount tube (MM01) and then remove it; the fit will be tight, and may even require a slight stretching of the mount tube (MM01)
  3. Make a mark 1/4" from one end of the red engine block (MM04)
  4. Cut the red engine block (MM04) at the 1/4" line from the previous step, keeping the larger section as the final engine block (see Figure 2)
    Figure 2 - Modified Engine Block (top) vs Original Engine Block (bottom)
  5. Follow Step 1 in the Estes D & E Engine Mount Kit instructions
    1. Step 1.A - Make a mark on the mount tube (MM01) 1" from the rear, and make another mark 5/8" from the front [this second mark should be offset along the circumference of the mount tube (MM01) slightly]
    2. Step 1.B - Cut a 1/8" wide slit at the mark 1" from the rear of the mount tube (MM01); insert the engine hook (MM05) into the slit (see Figure 3)
      Figure 3 - Engine hook inserted into mount tube
    3. Step 1.C - Apply wood glue to the outside of engine block (MM06) and the inside of the inside of the rear section of the mount tube (MM01) making sure to completely coat the inside of the mount tube (MM01) up to where the engine hook (MM05) is inserted; Slide the engine block (MM06) into the rear of the mount tube (MM01) until it rests agains the engine hook (MM05); be sure to smooth any excess glue in the mount tube (MM01) to create a smooth water tight surface (see Figure 4)
      Figure 4 - Engine block inserted into mount tube
  6. Follow Step 2 in the Estes D & E Engine Mount Kit instructions - Apply a bead of wood glue around the mount tube (MM01) just to the rear of the mark 5/8" from the front and then slide the engine retainer ring (MM02) onto the the mount tube (MM01) from the front of the mount tube (MM01) until the engine retainer ring (MM02) is just past the 5/8" mark (see Figure 5)
    Figure 5 - Engine retainer ring mounted
  7. Allow the assembly to dry overnight
  8. Apply a bead of multi-surface glue to the edge of the base end of the t-connector (MM06)
  9. Insert the t-connector (MM06) into the rear of the mount tube (MM01) (see Figure 6)
    Figure 6 - Completed motor mount
  10. Allow the motor mount to dry over night

Motor Mount Bracket

  1. Prepare the plate (MMB01)
    1. Drill the four 1/4" through holes for the zip ties (MMB04) (see Figure 7)
      Figure 7 - MMB01 with zip tie holes highlighted
    2. Drill and counterbore the two 3/32" through holes for the machine screws (see Figure 8)
      Figure 8 - MMB01 with machine screw holes highlighted
    3. Create the two 1/4" dados on the bottom of the plate (MMB01) to provide space for the zip ties (MMB04); this can be done on a table saw with either a dado blade or with multiple passes using a standard 1/8" wide blade (see Figure 9)
      Figure 9 - MMB01 with dados highlighted
  2. Clamp the block (MMB02) to the rear edge of the plate (MMB01) (see Figure 10)
    Figure 10 - Block clamped to plate
  3. Drill pilot holes for the two 1-1/2" drywall screws
  4. Attach the block (MMB02) to the plate (MMB01) using two 1-1/2" drywall screws, making sure to leave approximately 1/8" of the rear screw exposed

Main Structure

Figure 11 - Exploded Assembly View

  1. Assemble the Test Stand Base; Note: it is significantly easier to assemble the Test Stand Base using the concrete block (TSBa05) as a stand/jig
    1. Place the top (TSBa02) on the concrete block (TSBa05) so that the rear edge is flush with the concrete block (TSBa05)
    2. Place the two sides (TSBa01) along the edge of the concrete block (TSBa05) so the front edges of the sides (TSBa01) are flush with the front of the top (TSBA02)
    3. Clamp the sides (TSBa01) to the top (TSBa02)
    4. Drill pilot holes through the sides (TSBa01) into the top (TSBa02) [3 on each side], and use 2-1/2" dry wall screws (TSBa04) to attach the sides (TSBa01) to the top (TSBa02); be sure to remove the clamps
    5. Place the front (TSBa03) under the top so it rests against the concrete block (TSBa05)
    6. Drill pilot holes through the sides (TSBa01) [1 each side] and the top (TSBa02) [2 holes] into the front (TSBa03), and use 2-1/2" dry wall screws (TSBa04) to attach the front (TSBa03)
  2. Attach the Test Section Beam
    1. Remove the Test Stand Base from the concrete block (TSBa05)
    2. Draw a line down the centerline of the long axis of the top (TSBa02)
    3. Place and clamp the beam (TSBe01) along the line on the top (TSBa02)
    4. Turn the Test Stand Base on its side and drill 3 pilot holes through the top (TSBa02) and into the beam (TSBe01), and use the 2-1/2" dry wall screws (TSBe02) to attach the beam (TSBe01) to the top (TSBa02); be sure to remove the clamps
  3. Prepare the Back Plate
    1. Drill the 3/8" pass-through hole in the back plate (BP01)
    2. Place the Test Stand Base back on the concrete block (TSBa05)
    3. Place the back plate (BP01) against the back of the Test Stand Base [it should fit between the sides and rest against the concrete block (TSBa05) and the beam (TSBe01)]
    4. Drill 2 pilot holes through each side (TSBa01) into the back plate (BP01)
    5. Drill 1 pilot hole through the back plate (BP01) into the beam (TSBe01)
    6. Note: Do not attach the back plate (BP01) yet.
  4. Treat the test stand components with heat resistant paint
    1. In a well ventilated area, lay out all of the wooden components and apply two coats of heat resistent primer (see Figure 12)
      Figure 12 - Priming Shepard components
    2. Allow primer to dry per manufacture's instructions
    3. Apply two coats of heat resistent paint (see Figure 13)
      Figure 13 - Painting Shepard components
    4. Allow paint to dry per manufacturer's instructions

Final Assembly

  1. Insert the two zip ties (MMB04) into the Motor Mount Bracket (see Figure 14)
    Figure 14 - Zip tie placement
  2. Use the metal screws (MMB03) to attach the Motor Mount Bracket to the end of the drawer slide (RS01) (see Figure 15)
    Figure 15 - Motor Mount Bracket attached to Drawer Slide
  3. Attach the drawer slide (RS01) to the beam (TSBe01) using 1-1/2" drywall screws (RS02) (see Figure 16)
    Figure 16 - Drawer Slide attached to Beam
  4. Place Motor Mount on Motor Mount Bracket and close the zip ties (MMB04) snuggly; note, be sure to have a motor in the motor mount to prevent the zip ties from crushing the Motor Mount (see Figure 17)
    Figure 17 - Attaching the Motor Mount
  5. Trim the excess portion of the zip ties (MMB04) (see Figure 18)
    Figure 18 - Trimming zip ties
  6. Place the Back Plate in position and attach it to the Test Stand Base with 2-1/2" drywall screws (BP03) (see Figure 19)
    Figure 19 - Attaching the Back Plate
  7. Attach the 1-1/2" dry wall screw (BP04) to the Back Plate just above the through hole leaving approximately 1/2" exposed; this screw is used to hang the small pulley (BP02)
  8. Use thin double-sided tape to attach the contact pad (MMB05) to the side of the motor mount block (MMB02) facing the back plate (BP01); note, be sure to align the contact pad with the Force Sensing Resistor mounting specified below

This completes the Mechanical System assembly process.

Data Acquisition (DAQ) System

The assembly of the DAQ system consists of three main sub-assemblies:
  1. MAX31855 Thermocouple Amplifier Breakout Board
  2. Force Sensing Resistor (FSR) cable system
  3. Arduino ProtoShield

MAX31855 Thermocouple Amplifier Breakout Board

Force Sensing Resistor (FSR) cable system

Arduino ProtoShield

Components were soldered onto the ProtoShield in the configuration shown in the images below. Note that in the bottom view, the ProtoShield has been flipped vertically towards the bottom of the picture. This allows you to orient yourself so that you can follow the traces. For higher resolution images to aid in assembly, check the Shepard_v1.0_DAQ_Assembly_Images.zip file here

Figure 20 - Top View of the ProtoShield

  1. The MAX 31855 breakout board has the correct header pin spacing to fit the holes on the ProtoShield, so it was inserted directly. Note that the capacitor that is included with the K type thermocouple when purchased is being used. The thermocouple's reading had too much noise in it otherwise.
  2. The red and green wires used were breadboard prototyping jumpers from Radio Shack. Left over Ethernet cable wires can be used as well.
  3. The resistor was soldered directly to the ProtoShield, but care should be taken that the leads of the resistor do not short any of the connections on the board.
  4. A 14 pin DIP socket was used for the TLV2374 for multiple reasons including prevention of overheating of the IC during soldering, and ease of replacement in the event of damage due to a wiring mistake.
  5. A smaller screw terminal block for the FSR leads (left side) would have ideal, but the larger block pictured was all that was available at the time of assembly. The pins are spaced more widely on the block and thus the positioning was dictated by the spacing of the holes on the ProtoShield.
  6. Notice that even though the two green jumper wires disappear under the MAX 31855 breakout board in the image, they have been labeled with what pins they go from/to.

Figure 21 - Bottom View of the ProtoShield

  1. If you view the high resolution version of this image from the Shepard_v1.0_DAQ_Assembly_Images.zip file here , you'll notice that several solder bridges have been made to connect different points. Use the schematic diagram found in the Shepard_v1.0_DAQ.zip file here to give you a more complete view of what's being bridged.
  2. The solder bridges are made by laying short lengths of stripped solid wire against the pins (or in the holes) and then soldering them.
  3. Figure 22 labels what the corresponding top side connections are for most of the solder joints.

Figure 22 - Bottom View of ProtoShield With Landmark Connections

  1. The solder positions where the green and white/green wires are coming off the board is the location of the Force Sensing Resistor (FSR) screw terminal.

Assembly v1.0

This document has been relinked to the Assembly document here as part of our versioning system update.

See the assembly instructions here

Shepard Test Stand Block Diagram v1.1

This block diagram discussion can be found on the forums here

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.


( SVG Format )

Shepard Test Stand Block Diagram v1.0

This document has been relinked to the Block Diagram document here as part of our versioning system update.

This block diagram discussion can be found on the forums here

Gelled: 2012-06-01 v0.4

Shepard Test Stand BOM v1.1

Shepard v1.1

Shepard Test Stand Budget v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Overview

The budget is $200, firm. If there is a conflict between function and budget, for this iteration, budget should trump. Our goal is not to make the perfect test stand, it is to upgrade the first prototype (v1.0) of the test stand in a way that gives us an upgrade path to v2.0 and beyond. In the process we will continue to learn both about test stands, and about our processes within our distributed design framework. Holding to a firm budget minimizes the amount of time spent trying to make the stand perfect (once you are out of money, you have to wrap up the project, successful or not). Even an "unsuccessful" prototype will teach us important lessons to apply moving forward. This budget does not include "consumables" such as motors, nor tools, but the $200 cost for the stand itself keeps the basic project affordable if standard tools found in Makerspaces can be used. Any manufacturing that has to be hired out to a third party will be taken out of the $200 budget, and should be avoided to keep this project more practical for those same Makerspaces.

Detailed Budget

Preliminary Mechanical Cost Estimates (For One-Off Quantities)
Item Cost (Minus Shipping) Link
8' 2x10 pine board $7.75
8' 2x4 pine board $2.50
4"x8"x16" solid concrete block $1.50
Small Ball Bearing Drawer Guide $6.00
30 Ga Sheel Metal $7.93 Link
Pulley $3.31 Link
Estes D/E Motor Mount $9.00 Link
Estes Motor Adapters $6.00 Link
Copper T-Fitting $3.00
High Heat Spray Primer $8.00
High Heat Spray Paint $5.00
Misc Hardware (Screws, etc) $5.00
Total $64.99
Preliminary DAQ Cost Estimates (For One-Off Quantities)
Item Quantity Unit Cost (Minus Shipping) Cost to Builder (Including Shipping) Link
Arduino Uno R3 1 $29.95 $37.09 Link
Arduino Protoshield 1 $16.50 $20.45 Link
5 Kg Micro Load Cell 1 $6.80 $19.96 Link
INA122 Instrumentation Amplifier 1 $8.02 $13.02 Link
Melexis MLX90614 IR Temperature Sensor 1 $12.40 $17.74 Link
8-Pin DIP Socket 1 $0.99 $1.06 Link
10K Micro Trim Poteniometer 1 $1.99 $2.13 Link
15 Ohm Resistor 1 $0.10 $0.11 Link
150 Ohm Resistor 1 $0.10 $0.11 Link
2 x 3.5 mm Screw Terminal 2 $0.35 $0.82 Link
Misc (Wire, Shrink Tubing, etc) 1 $2.00 $2.00
Totals $79.20 $114.49

Total Project Cost:
$179.48 ($20.52 under budget)

Budget v1.0

This document has been relinked to the Budget document here as part of our versioning system update.

Overview

The budget is $200, firm. If there is a conflict between function and budget, for this iteration, budget should trump. Our goal is not to make the perfect test stand, it is to make the first prototype of a test stand and see what we can learn from that experience (both about test stands, and about our processes). We can always go back and do another iteration to meet the design requirements if needed. Holding to a firm budget minimizes the amount of time spent trying to make it perfect (once you are out of money, you have to wrap up the project, successful or not). Even a "unsuccessful" prototype will teach us important lessons to apply moving forward. This budget does not include "consumables" such as motors, nor tools, but the $200 cost for the stand itself keeps the basic project affordable if standard tools found in hackerspaces can be used. Any manufacturing that has to be hired out to a third party will be taken out of the $200 budget, and should be avoided to keep this project more practical for those same hackerspaces.

Detailed Budget

Preliminary Mechanical Cost Estimates (For One-Off Quantities)
Item Cost (Shipping to Midwest U.S.) Approx Total Link
8' 2x10 pine board $7.75 $7.75
8' 2x4 pine board $2.50 $2.50
4"x8"x16" solid concrete block $1.50 $1.50
Small Ball Bearing Drawer Guide $6.00 $6.00
Pulley $3.00 $3.00
Estes D/E Motor Mount $9.00 $9.00 http://bit.ly/Rrn330
Estes Motor Adapters $6.00 $6.00 http://bit.ly/MYMnNg
Copper T-Fitting $3.00 $3.00
High Heat Spray Primer $8.00 $8.00
High Heat Spray Paint $5.00 $5.00
Misc Hardware $5.00 $5.00
Total $56.75

Note: Need to address shielding in the cost table above.

Preliminary DAQ Cost Estimates (For One-Off Quantities)
Item Cost (Shipping to Midwest U.S.) Approx Total Link
Arduino Uno R3 $29.95 + shipping $35 http://bit.ly/N5kizl
Arduino Protoshield $16.50 + shipping $20.45 http://bit.ly/S7I466
1.5 Inch Square FSR $7.95 + shipping $16 http://bit.ly/Pd3ztz
TLV2374 Op Amp $1.71 + shipping $8 http://bit.ly/OcVA12
560 Ohm Resistor x 2 $0.20 (combined w/ shipping above) $0.20 http://bit.ly/M3duBJ
Type-K Glass Braid Insulated Thermocouple $10.00 + shipping $13.87 http://bit.ly/NPRosE
Adafruit Thermocouple Amplifier $17.50 + shipping $21.50 http://bit.ly/OqVc2A
Misc (Wire, Tape, etc) $5.00
Total $120.02

Total Project Cost:
$176.77 ($23.23 under budget)

Shepard Test Stand Design Review v1.1

There was no formal review of the v1.1 design since it was a minor incremental upgrade.

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Design Review v1.0

This document has been relinked to the Design Review document here as part of our versioning system update.

Shepard Test Stand Detailed Design v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Introduction

The Shepard Test Stand design is broken down into two main components. The first is the mechanical system, and the second is the Data Acquisition (DAQ) system. The mechanical system consists of the frame of the test stand, as well as the motor mounting mechanism and mounts for the thrust and temperature sensors. The DAQ system handles the task of collecting the data from the sensors and presenting them to the user in a way that facilitates motor testing.

Mechanical System

Component Overview

The Shepard Test Stand v1.0 mechanical system (pictured above) is made up of six key components. They are:

  1. Test Stand Base - The Test Stand Base (Base) is constructed from ripped down 2x10 pine stock, and fits over a 4" x 8" x 16" (nominal) solid concrete block which is available at most hardware stores. The outer dimensions of the Base are 10-7/8" x 21-1/2" x 5-3/16", and its inner dimensions are 7-3/4" x 15-5/8" x 3-1/2". The key dimensions of the base are the inner dimensions (to allow the base to fit over the concrete block during operation) and an open platform of 20" in length to accommodate the Test Section Beam.
  2. Back Plate - The Back Plate is constructed from ripped down 2x10 pine stock. Its function is to provide resistance to the thrust, and a mounting location for the force sensor (on the side facing the motor) and the DAQ electronics (on the side opposite the force sensor). The dimensions of the Back Plate are 7-3/4" x 14" x 1-1/2" (with 8-13/16" sticking up above the base). The key dimensions are the width (to match the top of the Base) and the height (which should be no less than 8" to provide enough space to mount the force sensor and the electronics). Note, there may be one or more holes in the Back Plate to feed wires from the sensors to the DAQ board (or other purposes). In the current version, there is one 3/8" diameter hole drilled through the center of the Back Plate approximately 3-7/8" above the Base to allow a cord from the Motor Mount Bracket to facilitate calibration. After passing through the Back Plate the cord goes over a pulley mounted on the back side of the Back Plate so weights can be hung from the cord to simulate thrust applying force to the force sensor.
  3. Test Section Beam - The Test Section Beam (Beam) is constructed from a 2x4 pine board, and sits vertically on top of the Base, along the center line. It is 20" long (6" longer than the Rail System) to provide room for the Rail System to retract the Motor Mount and Motor Mount Bracket away from the Back Plate for maintenance. The key dimension is its length.
  4. Rail System - The Rail System restricts the motor under test to motion along the initial thrust vector. It is made from a Liberty 14 inch Ball Bearing Drawer Slide (PN D80614C-ZP-W, available at Home Depot). Note, this was the shortest ball bearing drawer guide available at the time of testing. If a shorter drawer guide is found, the overall length of the test stand could be reduced. It is installed along the top of the Beam along the Beam's center line.
  5. Rail Shield (not shown) - Testing of v1.0 showed the Rail System was prone to becoming fouled by the exhaust from the motor under test. To protect the Rail System, a sheet metal guard, or Rail Shield, was added to the v1.1 design. The Rail Shield is a folded sheet piece of sheet metal sized and shaped to completely cover the portion of the Rail System in front of the Motor Mount. It is attached to the test stand with screws (for a small Rail Shield, it is attached to the Rail System; for a large Rail Shield, like the one used by CCSSC, it is attached to the Test Stand Base).
  6. Motor Mount - The Motor Mount is based on an Estes D and E Engine Mount Kit (PN 303159). It is assembled according to the instructions for E size motors with four modifications.
    1. It is assembled without "Centering Rings" (the cardboard rings used to connect the mount to a rocket body)
    2. 1/4" is removed from the "Engine Block" to leave room for a 3/4" copper plumbing t-connector to be inserted into the aft end of the mount
    3. A layer of wood glue is spread on the inside of the motor mount at the aft end to seal the surface which will be glued to the t-connector
    4. A 3/4" copper t-connector is glued into the aft end of the motor mount to redirect the ejection charge
  7. Motor Mount Bracket - The Motor Mount Bracket provides a connection between the Motor Mount and the Rail System. It is a 1/2" thick plate with a block on the aft end sized to provide the correct contact area with the force sensor. The current version is constructed from 1/2" sheet of pine plywood (to create the plate) and a pine block cut from a 2x4. The plate's dimensions are 6-1/4" x 1-23/32" x 1/2" (the 1-23/32" dimension is set to fit the selected force sensor). The block is 1-1/2" x 1-7/32" x 1-23/32". The critical dimensions are the overall length of the plate (sufficient to accommodate the block and the Motor Mount) and the area presented at the back of the Motor Mount Bracket (sized for the force sensor). The Motor Mount is attached to the Motor Mount Bracket using 2 plastic zip ties (rated at least 50 lbf), one over the t-connector and the other over the "Engine Retainer Ring" at the front of the Motor Mount. The Motor Mount Bracket has a number of holes drilled into it. Two countersunk holes are used to attach the Motor Mount Bracket to the Rail System. Four straight-through holes are used to allow the zip ties to pass through the Motor Mount Bracket. Finally, two grooves are cut in the bottom of the Motor Mount Bracket to give the zip ties room between the Rail System and the Motor Mount Bracket. Many of these details can be seen in the image below.

Note: All of the wooden components are covered in 2 coats of heat resistant spray on primer and 2 coats of heat resistant paint.

CAD Files

The CAD files for this version of the test stand are located in the Shepard_v1.0_CAD.zip file here and include the following:
  1. Drafts in PDF and SVG formats in the Drafts directory.
  2. An exploded view in PNG and SVG formats in the Images directory.
  3. Files in the Orig_Assemblies directory in the FreeCAD format, including the complete assembly and the exploded assembly.
  4. Files in the Orig_Parts directory in the FreeCAD format, which are the individual part files for the test stand.
  5. STEP versions of the part files stored in the STEP_Files directory, which were used to build the assemblies.
  6. The Templates directory holding two templates that are used with FreeCAD for the drafts/drawings. A4_Landscape_Simple.svg is a blank template that can be used to remove the title block from a drawing. A4_Mach_30_Title_Block.svg is the Mach 30 specific title block used in all the drafts/drawings.

Data Acquisition (DAQ) System

Component Overview

The Shepard Test Stand v1.0 Data Acquisition (DAQ) system (pictured above) is made up of four key components. They are:

  1. Arduino Uno - The Arduino Uno is an open hardware electronics prototyping platform that serves as the base for the test stand's DAQ system.
  2. Arduino Proto Shield - The Arduino Proto Shield is a pre-built shield for the Arduino Uno that allows a developer to easily package their components for the platform. There is a general overview of the components on the test stand's proto shield below.
  3. Force Sensing Resistor (FSR) - The FSR is a variable resistor who's resistance changes as pressure is applied to its contact area. These resistors are very low cost, but have issues with accuracy and drift, among others. For this prototype which used an FSR with male connectors, a custom cable was made using CAT 5 Ethernet cable and D-SUB pins to connect the FSR to the Arduino Uno. UPDATE: The FSR that was selected had an effective measurement range from 0.1 to 10 Newtons, which was too low for the rocket motors being tested since some could generate a peak thrust of nearly 30 Newtons. This was an oversight that ended up being a moot point because of the FSRs other shortcomings.
  4. Type K Thermocouple - The thermocouple has a 1-meter long fiberglass braided cable and can read temperatures of up to 500 °C.

  1. MAX31855 Thermocouple Amplifier Breakout Board - Available from Adafruit Industries, this amplifier is designed to work with any K-type themocouple and gives output from -200 °C to 1350 °C in 0.25 °C increments. It uses a SPI data interface with a built-in 14-bit ADC, and requires 70 to 100 ms to do a conversion. UPDATE: This slow conversion time seems to be the biggest factor limiting our overall data collection sample rate to around 15 samples/sec.
  2. 0.01uF Capacitor - This capacitor is wired in parallel with the thermocouple and helps smooth out the sampling jitter in noisy environments.
  3. 560 Ohm Resistor - This resistor is one side of a voltage divider, with the FSR being the other. This allows us to convert the change in resistance of the FSR to a voltage so that it can be measured by the Arduino Uno.
  4. TLV2374IN Quad 3MHz Op Amp - This TLV2374 is in a DIP package to make it easier to prototype. This IC is used to amplify the voltage from the FSR to a level suitable for the analog inputs of the Arduino Uno.
  5. 14 Pin IC Socket - Lying beneath the TLV2374, this is used to make it possible to swap out TLV2374 ICs if one is damaged in prototyping, and also prevents heat from the soldering iron from being transferred directly into the IC during assembly.

Electrical Schematics and PCB Files

There are no PCB files for this version of the Shepard Test Stand at this time.

You can find the schematic files in the DMSF plugin here

An image of the schematic is shown below.

Attached Files

Shepard Test Stand Detailed Design v1.0

This document has been relinked to the Detailed Design document here as part of our versioning system update.

Introduction

The Shepard Test Stand design is broken down into two main components. The first is the mechanical system, and the second is the Data Acquisition (DAQ) system. The mechanical system consists of the frame of the test stand, as well as the motor mounting mechanism and mounts for the thrust and temperature sensors. The DAQ system handles the task of collecting the data from the sensors and presenting them to the user in a way that facilitates motor testing.

Mechanical System

Component Overview

The Shepard Test Stand v1.0 mechanical system (pictured above) is made up of six key components. They are:

  1. Test Stand Base - The Test Stand Base (Base) is constructed from ripped down 2x10 pine stock, and fits over a 4" x 8" x 16" (nominal) solid concrete block which is available at most hardware stores. The outer dimensions of the Base are 10-7/8" x 21-1/2" x 5-3/16", and its inner dimensions are 7-3/4" x 15-5/8" x 3-1/2". The key dimensions of the base are the inner dimensions (to allow the base to fit over the concrete block during operation) and an open platform of 20" in length to accommodate the Test Section Beam.
  2. Back Plate - The Back Plate is constructed from ripped down 2x10 pine stock. Its function is to provide resistance to the thrust, and a mounting location for the force sensor (on the side facing the motor) and the DAQ electronics (on the side opposite the force sensor). The dimensions of the Back Plate are 7-3/4" x 14" x 1-1/2" (with 8-13/16" sticking up above the base). The key dimensions are the width (to match the top of the Base) and the height (which should be no less than 8" to provide enough space to mount the force sensor and the electronics). Note, there may be one or more holes in the Back Plate to feed wires from the sensors to the DAQ board (or other purposes). In the current version, there is one 3/8" diameter hole drilled through the center of the Back Plate approximately 3-7/8" above the Base to allow a cord from the Motor Mount Bracket to facilitate calibration. After passing through the Back Plate the cord goes over a pulley mounted on the back side of the Back Plate so weights can be hung from the cord to simulate thrust applying force to the force sensor.
  3. Test Section Beam - The Test Section Beam (Beam) is constructed from a 2x4 pine board, and sits vertically on top of the Base, along the center line. It is 20" long (6" longer than the Rail System) to provide room for the Rail System to retract the Motor Mount and Motor Mount Bracket away from the Back Plate for maintenance. The key dimension is its length.
  4. Rail System - The Rail System restricts the motor under test to motion along the initial thrust vector. It is made from a Liberty 14 inch Ball Bearing Drawer Slide (PN D80614C-ZP-W, available at Home Depot). Note, this was the shortest ball bearing drawer guide available at the time of testing. If a shorter drawer guide is found, the overall length of the test stand could be reduced. It is installed along the top of the Beam along the Beam's center line.
  5. Motor Mount - The Motor Mount is based on an Estes D and E Engine Mount Kit (PN 303159). It is assembled according to the instructions for E size motors with four modifications.
    1. It is assembled without "Centering Rings" (the cardboard rings used to connect the mount to a rocket body)
    2. 1/4" is removed from the "Engine Block" to leave room for a 3/4" copper plumbing t-connector to be inserted into the aft end of the mount
    3. A layer of wood glue is spread on the inside of the motor mount at the aft end to seal the surface which will be glued to the t-connector
    4. A 3/4" copper t-connector is glued into the aft end of the motor mount to redirect the ejection charge
  6. Motor Mount Bracket - The Motor Mount Bracket provides a connection between the Motor Mount and the Rail System. It is a 1/2" thick plate with a block on the aft end sized to provide the correct contact area with the force sensor. The current version is constructed from 1/2" sheet of pine plywood (to create the plate) and a pine block cut from a 2x4. The plate's dimensions are 6-1/4" x 1-23/32" x 1/2" (the 1-23/32" dimension is set to fit the selected force sensor). The block is 1-1/2" x 1-7/32" x 1-23/32". The critical dimensions are the overall length of the plate (sufficient to accommodate the block and the Motor Mount) and the area presented at the back of the Motor Mount Bracket (sized for the force sensor). The Motor Mount is attached to the Motor Mount Bracket using 2 plastic zip ties (rated at least 50 lbf), one over the t-connector and the other over the "Engine Retainer Ring" at the front of the Motor Mount. The Motor Mount Bracket has a number of holes drilled into it. Two countersunk holes are used to attach the Motor Mount Bracket to the Rail System. Four straight-through holes are used to allow the zip ties to pass through the Motor Mount Bracket. Finally, two grooves are cut in the bottom of the Motor Mount Bracket to give the zip ties room between the Rail System and the Motor Mount Bracket. Many of these details can be seen in the image below.

Note: All of the wooden components are covered in 2 coats of heat resistant spray on primer and 2 coats of heat resistant paint.

CAD Files

The CAD files for this version of the test stand are located in the Shepard_v1.0_CAD.zip file here and include the following:
  1. Drafts in PDF and SVG formats in the Drafts directory.
  2. An exploded view in PNG and SVG formats in the Images directory.
  3. Files in the Orig_Assemblies directory in the FreeCAD format, including the complete assembly and the exploded assembly.
  4. Files in the Orig_Parts directory in the FreeCAD format, which are the individual part files for the test stand.
  5. STEP versions of the part files stored in the STEP_Files directory, which were used to build the assemblies.
  6. The Templates directory holding two templates that are used with FreeCAD for the drafts/drawings. A4_Landscape_Simple.svg is a blank template that can be used to remove the title block from a drawing. A4_Mach_30_Title_Block.svg is the Mach 30 specific title block used in all the drafts/drawings.

Data Acquisition (DAQ) System

Component Overview

The Shepard Test Stand v1.0 Data Acquisition (DAQ) system (pictured above) is made up of four key components. They are:

  1. Arduino Uno - The Arduino Uno is an open hardware electronics prototyping platform that serves as the base for the test stand's DAQ system.
  2. Arduino Proto Shield - The Arduino Proto Shield is a pre-built shield for the Arduino Uno that allows a developer to easily package their components for the platform. There is a general overview of the components on the test stand's proto shield below.
  3. Force Sensing Resistor (FSR) - The FSR is a variable resistor who's resistance changes as pressure is applied to its contact area. These resistors are very low cost, but have issues with accuracy and drift, among others. For this prototype which used an FSR with male connectors, a custom cable was made using CAT 5 Ethernet cable and D-SUB pins to connect the FSR to the Arduino Uno. UPDATE: The FSR that was selected had an effective measurement range from 0.1 to 10 Newtons, which was too low for the rocket motors being tested since some could generate a peak thrust of nearly 30 Newtons. This was an oversight that ended up being a moot point because of the FSRs other shortcomings.
  4. Type K Thermocouple - The thermocouple has a 1-meter long fiberglass braided cable and can read temperatures of up to 500 °C.

  1. MAX31855 Thermocouple Amplifier Breakout Board - Available from Adafruit Industries, this amplifier is designed to work with any K-type themocouple and gives output from -200 °C to 1350 °C in 0.25 °C increments. It uses a SPI data interface with a built-in 14-bit ADC, and requires 70 to 100 ms to do a conversion. UPDATE: This slow conversion time seems to be the biggest factor limiting our overall data collection sample rate to around 15 samples/sec.
  2. 0.01uF Capacitor - This capacitor is wired in parallel with the thermocouple and helps smooth out the sampling jitter in noisy environments.
  3. 560 Ohm Resistor - This resistor is one side of a voltage divider, with the FSR being the other. This allows us to convert the change in resistance of the FSR to a voltage so that it can be measured by the Arduino Uno.
  4. TLV2374IN Quad 3MHz Op Amp - This TLV2374 is in a DIP package to make it easier to prototype. This IC is used to amplify the voltage from the FSR to a level suitable for the analog inputs of the Arduino Uno.
  5. 14 Pin IC Socket - Lying beneath the TLV2374, this is used to make it possible to swap out TLV2374 ICs if one is damaged in prototyping, and also prevents heat from the soldering iron from being transferred directly into the IC during assembly.

Electrical Schematics and PCB Files

There are no PCB files for this version of the Shepard Test Stand at this time.

You can find the schematic files in the DMSF plugin here

An image of the schematic is shown below.

Attached Files

Development Logs

Temperature Measurement

Thrust Measurement

Structure

Shepard Test Stand Disposal v1.1

According to the project requirements , the following guidelines must be followed when building, operating, and disposing of the test stand and/or its consumables.

STSR 11.1 Disposal of the spent Estes motors should conform to all local, state, and federal guidelines.
STSR 11.2 Electronic waste items, including batteries and circuit boards, must also be disposed of according to all local, state, and federal guidelines.
STSR 11.3 If the frame of the STS is damaged beyond repair during operation, proper disposal/recycling guidelines must be followed for the materials used in its construction.
STSR 11.4 Wherever possible, the STS design should make it as easy as possible to replace components which are consumable or relatively easy to damage.

Furthermore, under the section labeled "Disposal of standard Estes engines" here there are instructions for disposing of Estes motors properly.

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Disposal v1.0

This document has been relinked to the Disposal document here as part of our versioning system update.

According to the project requirements , the following guidelines must be followed when building, operating, and disposing of the test stand and/or its consumables.

STSR 11.1 Disposal of the spent Estes motors should conform to all local, state, and federal guidelines.
STSR 11.2 Electronic waste items, including batteries and circuit boards, must also be disposed of according to all local, state, and federal guidelines.
STSR 11.3 If the frame of the STS is damaged beyond repair during operation, proper disposal/recycling guidelines must be followed for the materials used in its construction.
STSR 11.4 Wherever possible, the STS design should make it as easy as possible to replace components which are consumable or relatively easy to damage.

Furthermore, under the section labeled "Disposal of standard Estes engines" here there are instructions for disposing of Estes motors properly.

Shepard Test Stand Errata v1.1

There are the problems that have been discovered with the current design.

  1. It has been mentioned that the cut list has some errors in cut lengths, but the incorrect cuts were not documented. However, these errors cause the cuts to be too long, so no material will be wasted during the build process.
  2. The data acquisition (DAQ) system is not capable of sample rates in excess of 15 samples per second. This is due to the fact that the thermocouple amplifier requires 70 to 100 milliseconds to do a temperature conversion (A to D). This is an unacceptably slow sample rate. The target for future iterations up through version 2.x should be a minimum of 200 samples per second.
  3. The contact between the Force Sensing Resistor's (FSR's) backing plate and the motor mount's contact plate is not completely parallel. This causes skewed results with the FSR.
  4. There was a process breakdown among the Shepard team that caused some Shepard v2.0 DAQ features to be mixed into the development logs and wiki for v1.1. The documentation has been cleaned up, but may still contain some v2.0 contamination that was missed.

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Errata v1.0

This document has been relinked to the Errata document here as part of our versioning system update.

There are a four main problems with the current design that will need to be addressed in future iterations (v1.1+).

  1. The drawer guide that is being used as a linear guide is not properly shielded from motor exhaust particulates, and thus the guide's bearings tend to foul after less than 30 test firings.
  2. The data acquisition system is not capable of sample rates in excess of 15 samples per second. This is due to the fact that the thermocouple amplifier requires 70 to 100 milliseconds to do a temperature conversion (A to D). This is an unacceptably slow sample rate. The target for future iterations up to version 2.0 should be a minimum of 150 samples per second.
  3. The Force Sensing Resistor (FSR) used will not measure forces in excess of 10.0 Newtons. Some of the motors that this stand tests can exert a trust of 25 to 30 Newtons, so this is unacceptable because the full range of thrust cannot be measured.
  4. The contact between the FSR's backing plate and the motor mount's contact plate was not completely parallel in version 1.0. This causes skewed results with the FSR. This should be corrected in future 1.x versions as much as the material (wood) allows.

General Overview

The Shepard Test Stand is a test stand for Estes rocket motors. It is named after Alan Shepard, America's first astronaut, as it is our first test stand. We anticipate using an Arduino board to provide the physical interface between the data collecting computer and the required sensors. This project is the first in a series of projects to develop the required skills for the practice of safe rocket engine operation, and to develop the capability to measure and record data about a rocket engine's performance. The use of Estes class motors provides a relatively safe environment to learn in before moving to higher powered motors and engines. The ultimate vision is to develop test stands for full scale liquid rocket engines for use in orbital launch systems.

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

General Overview v1.0

This document has been relinked to the General Overview document here as part of our versioning system update.

The Shepard Test Stand is a test stand for Estes rocket motors. It is named after Alan Shepard, America's first astronaut, as it is our first test stand. We anticipate using an Arduino board to provide the physical interface between the data collecting computer and the required sensors. This project is the first in a series of projects to develop the required skills for the practice of safe rocket engine operation, and to develop the capability to measure and record data about a rocket engine's performance. The use of Estes class motors provides a relatively safe environment to learn in before moving to higher powered motors and engines. The ultimate vision is to develop test stands for full scale liquid rocket engines for use in orbital launch systems.

Shepard Test Stand Initial Questions v2.0

Below is a list of questions and proposed answers to help us narrow down the requirements for this project. You can view the original forum discussion here .

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Q1. Why are we making this?

A1. The Shepard Test Stand is the first step toward developing an open source test stand for flight capable rocket engines. It's focus on low power, commercially available amateur rocket motors is intended to provide a safe first experience for both designers (low power and low cost lead to little penalty for failing to meet design goals the first time around) and operators (low power leads to lower cost if accidentally misused during early training). Additionally, as one of Mach 30's earliest open source hardware projects, it will give us practical experience in open source hardware development and managing projects on Open Design Engine (ODE). Finally, we have received interest in performing live demonstrations of the test stand as part of educational and outreach activities, so it is expected the test stand will become an educational and marketing tool.

Q2. Who is this for?

A2. The Shepard Test Stand is for anyone wanting to learn about measuring the performance of rocket motors. This includes open source spaceflight designers who will design and build future test stands (at Mach 30 or elsewhere), Mach 30 operators who will use future test stands in other Mach 30 projects, students and educators who want to bring rocket engineering into the classroom, and anyone else interested in how rockets are tested. To ensure the Shepard Test Stand will be accessible to the entire user community, including users with no experience in spacecraft engineering, the Shepard Test Stand team has selected a representative user with limited experience in spacecraft engineering and testing hardware. This representative user is a middle school (6th through 8th grade in the U.S.) teacher who does not have the support of an IT department, and who does not have computer expertise beyond how to connect a USB cable and install software, but has the desire to introduce their students to rocket science in a safe and hands-on way.

Q3. How will this be used?

A3. The final test stand will be used for verification of typical motor performance metrics such as thrust and casing temperature. The thrust metric will be compared against benchmark values provided in the Estes motor documentation . The test stand will then be used as a tool to teach rocket engineering in classrooms, and to do demonstrations at various conferences and educational events (outdoor only).

Q4. What features does it need to have (now)?

A4. The test stand needs to:

Q5. What features does it need to have (later)?

These features will not necessarily make it into any version of Shepard, but should be kept in mind for any of its larger sibling test stands later on.

Q6. What are the legacy requirements?

A6. Two features of the v1.x test stand are very desirable in future versions.

  1. The structure should easily mount to a concrete block without the need for special tools or modifying the block.
  2. The DAQ should use an Arduino as the interface between the sensors and the data collection computer.

Q7. Who's going to build this?

A7. The designs will be open so that anyone, without necessarily a technical education in rocketry, propulsion, or engineering, would be able to build and operate a Shepard Test Stand. Specifically, in order to support the use of the Shepard Test Stand in classrooms, teachers and students should be able to build the test stand from parts or kits.

Q8. How many do we want to make?

A8. Previous efforts focused on developing the single initial prototype. The success of this prototype and the very strong interest in the use of the Shepard Test Stand in schools (middle school through college) has led Mach 30 to decide it will sell Shepard Test Stand kits for use in schools, scouting troupes, and makerspaces. This means developing the Shepard Test Stand into a finished product. So, the short answer to this question is "as many as the market demands."

Q9. What is the budget?

A9. Based on feedback form CCSSC, the final cost for Shepard Test Stand kits needs to be around $200 (though having a data component and being reusable like Shepard could allow for higher prices). Using the standard OSHW cost multiplier of 2.6, the total cost for parts and labor needs to be around $78 (note, the most recent experiments in structure design have a materials cost of about $40). To allow for several additional prototypes while still holding the materials cost down, the updated structure budget has a threshhold (maximum value) of $150 and an objective of $100.

Q10. What is the timeline?

A10. The v2.0 prototype (completed structure integrated with existing v2.0 prototype DAQ) needs to be complete and have its initial test firing by Dec 31, 2013. This timeline works with the efforts by the Coca-Cola Space Science Center to develop curriculum for the Shepard Test Stand (as long as they have early access to new structure prototypes).

Q11. What waste products will be produced by the manufacture and/or operation of this?

A11. Spent Estes motors will be a waste product of the operation of this test stand, and any residual materials should be treated as hazardous. Disposal of these motors should conform to all local, state, and federal guidelines. Estes motors are based on black powder propellant, so any motors that do not fire properly or are damaged can be disposed of in an ordinary manner by first soaking them in water until the casing unwraps and the propellant falls apart. Possible electronic waste items may include batteries from the ignition control box, and circuit boards. These must also be disposed of according to all local, state, and federal guidelines. If the frame of the test stand is damaged beyond repair during operation, proper disposal/recycling guidelines must be followed for the materials used in its construction.

Shepard Test Stand Initial Questions v1.0

This document has been relinked to the Initial Questions document here as part of our versioning system update.

Below is a list of questions and proposed answers to help us narrow down the requirements for this project. You can view the original forum discussion here

Q1. Why are we making this?

A1. The Shepard Test Stand is the first step toward developing an open source test stand for flight capable rocket engines. It's focus on low power, commercially available amateur rocket motors is intended to provide a safe first experience for both designers (low power and low cost lead to little penalty for failing to meet design goals the first time around) and operators (low power leads to lower cost if accidentally misused during early training). Additionally, as one of Mach 30's earliest open source hardware projects, it will give us practical experience in open source hardware development and managing projects on ODE. Finally, we have received interest in performing live demonstrations of the test stand as part of educational and outreach activities, so it is expected the test stand will become an educational and marketing tool.

Q2. Who is this for?

A2. The Shepard Test Stand is for anyone wanting to learn about measuring the performance of rocket motors. This includes open source spaceflight designers who will design and build future test stands (at Mach 30 or elsewhere), Mach 30 operators who will use future test stands in other Mach 30 projects, students and educators who want to bring rocket engineering into the classroom, and anyone else interested in how rockets are tested.

Q3. How will this be used?

A3. The final test stand will be used for verification of typical motor performance metrics such as thrust and exhaust temperature. These metrics will be compared against benchmark values provided in the Estes motor documentation . The test stand will also be used to do demonstrations at various conferences and educational events (outdoor only).

Q4. What features does it need to have (now)?

A4. The test stand needs to:

Q5. What features does it need to have (later)?

A5a. Version 2.0 A5b. Beyond Version 2.0

Q6. What are the legacy requirements?

A6. This is the first project of its kind at Mach 30, there are no existing projects it must interface with. However, if the system includes desktop control software, that software should run on all three major PC platforms (MS Windows, Mac OS X, and Linux). Additionally, it should use standard connections back to the control software (for example, USB, Ethernet, or similar connections).

Q7. Who's going to build this?

A7. It is assumed that volunteers within the Mach 30 community will build this test stand. The designs will be open so that ANYONE, without necessarily a technical education in rocketry, propulsion, or engineering, would be able to build and operate a Shepard test stand.

Q8. How many do we want to make?

A8. One (for now). If the design proves particularly valuable as a teaching or training tool, we may revisit this decision. If highly successful, it is not outside the realm of possibility to consider offering it (or a related design) as a kit for others to assemble.

Q9. What is the budget?

A9. $200, firm. If there is a conflict between function and budget, for this iteration, budget should trump. Our goal is not to make the perfect test stand, it is to make the first prototype of a test stand and see what we can learn from that experience (both about test stands, and about our processes). We can always go back and do another iteration to meet the design requirements if needed. Holding to a firm budget minimizes the amount of time spent trying to make it perfect (once you are out of money, you have to wrap up the project, successful or not). Even a "unsuccessful" prototype will teach us important lessons to apply moving forward. This budget does not include "consumables" such as motors, nor tools, but the $200 cost for the stand itself keeps the basic project affordable if standard tools found in hackerspaces can be used. Any manufacturing that has to be hired out to a third party will be taken out of the $200 budget, and should be avoided to keep this project more practical for those same hackerspaces.

Q10. What is the timeline?

A10. The goal is to complete the project within three months of formal launch as an exercise of agile design. However, given the project is also an experiment in open source hardware development and is all volunteer based, we need to recognize the need to be flexible in this requirement.

Q11. What waste products will be produced by the manufacture and/or operation of this?

A11. Spent Estes motors will be a waste product of the operation of this test stand, and any residual materials should be treated as hazardous. Disposal of these motors should conform to all local, state, and federal guidelines. Estes motors are based on black powder propellant, so any motors that do not fire properly or are damaged can be disposed of in an ordinary manner by first soaking them in water until the casing unwraps and the propellant falls apart. Possible electronic waste items may include batteries from the ignition control box, and circuit boards. These must also be disposed of according to all local, state, and federal guidelines. If the frame of the test stand is damaged beyond repair during operation, proper disposal/recycling guidelines must be followed for the materials used in its construction.

Gelled: 2012-05-03 v7

Shepard Test Stand Integration v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

There were no formal integration tests for version 1.1, but the information for version 1.0's tests is below.

There were two live integration tests, and both were performed at Club Cyberia in Indianapolis, IN. The first was a rough first pass at giving everything the opportunity to work together, and the second was intended to collect usable data.

First Integration Session

The first integration test is talked about in this forum post .

This video shows the first integrated firing of the test stand.

The software at this point was very rudimentary, and did little more than tell us the test stand had the potential to give data similar to the published Estes thrust curves. It was at this point that it was realized that a contact pad needed to be created for the interface between the motor mount block and the Force Sensing Resistor (FSR). This ensured that there was contact across the entire face of the FSR without contacting the border area. This is a requirement of the FSR to make sure that you get valid readings. The FSR and the contact pad were affixed to the stand with double sided tape that was thin and did not compress under load.

Second Integration Session

The second integration session yielded little usable data due to a glitch in the data collection software. However, J. was able to get a good deal of screen capture video from the software which ended up in the following demo reel. There is some picture in picture footage starting at about 3:10 which shows the physical firing of the test stand synchronized with the screen cast of the data collection software.

Integration v1.0

This document has been relinked to the Integration document here as part of our versioning system update.

There were two live integration tests, and both were performed at Club Cyberia in Indianapolis, IN. The first was a rough first pass at giving everything the opportunity to work together, and the second was intended to collect usable data.

First Integration Session

The first integration test is talked about in this forum post .

This video shows the first integrated firing of the test stand.

The software at this point was very rudimentary, and did little more than tell us the test stand had the potential to give data similar to the published Estes thrust curves. It was at this point that it was realized that a contact pad needed to be created for the interface between the motor mount block and the Force Sensing Resistor (FSR). This ensured that there was contact across the entire face of the FSR without contacting the border area. This is a requirement of the FSR to make sure that you get valid readings. The FSR and the contact pad were affixed to the stand with double sided tape that was thin and did not compress under load.

Second Integration Session

The second integration session yielded little usable data due to a glitch in the data collection software. However, J. was able to get a good deal of screen capture video from the software which ended up in the following demo reel. There is some picture in picture footage starting at about 3:10 which shows the physical firing of the test stand synchronized with the screen cast of the data collection software.

Shepard Test Stand Licensing and Attribution

Hardware - Mach 30 Open Design Pledge
Software - Apache License, 2.0
Documentation - Creative Commons Attribution

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Licensing and Attribution v1.0

This document has been relinked to the Licensing and Attribution document here as part of our versioning system update.

Hardware - Mach 30 Open Design Pledge
Software - Apache License, 2.0
Documentation - Creative Commons Attribution

Shepard Test Stand Meeting Minutes

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Version 2.0

08-01-13 09-05-13 09-12-13 09-19-13 09-26-13 10-17-13

Version 1.1

01-31-13 08-29-13

Version 1.0

03-01-12 04-26-12 05-17-12 06-14-12 06-27-12 06-28-12 07-25-12 08-16-12 08-23-12 08-30-12 09-20-12 09-23-12

Meeting Minutes v1.0

This document has been relinked to the Meeting Minutes document here as part of our versioning system update.

03-01-12 04-26-12 05-17-12 06-14-12 06-27-12 06-28-12 07-25-12 08-16-12 08-23-12 08-30-12 09-20-12 09-23-12

Shepard Test Stand Operating Manual v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Hardware Operation

Unpacking After Transport

  1. Check shipping container(s) for:
    1. Test stand
    2. Concrete block
    3. Box of accessories
      1. Launch controller
      2. D motor spacer ring
      3. Motor mount adapters (A, B, and C to D/E size)
      4. Thermocouple attachment tape (high temp)
    4. Computer and USB cable
    5. Motors to test (with igniters and igniter plugs)
    6. Fire extinguisher and maybe a bucket for water

Test Stand Setup

  1. Place concrete block in location where test stand will be operated
  2. Set test stand on concrete block
  3. Create the safety perimeter.
    1. Delineate no stand zone for both proximity and positions
      1. Use length of cord for the igniter (radius of operations)
      2. Exclusion zones exist behind where exhaust escapes (30 degree cone), and in front on each side of the exhaust T (30 degree cone on each side)
  4. Set up the management area for test.
    1. Igniter
      1. Clip the igniter to a part of the test stand and deploy the cable to its full length and place it where the test(s) will be run from
    2. Computer
      1. Set up computer
      2. Boot computer
      3. Run USB cable from computer to test stand
      4. Connect Arduino-based DAQ system to USB cable at test stand
      5. Start the Test Stand App
      6. Ensure DAQ system and Computer are both running and connected

Prepare For Test*

  1. Check the following areas of the test stand for fatigue damage and good fit.
    1. Motor mount
    2. Zip ties holding motor mount
    3. Linear guide rail system
  2. Clear any debris from linear guide rail system and ejection charge exhaust ports
  3. Test sensors
    1. Push on thrust sensor and confirm current value slider responds
    2. Put fingers around thermocouple(s) (after ensuring it is not hot) and confirm plot responds
  4. Install motor in test stand
    1. A-C Motors
      1. Attach thermocouple(s)
      2. Insert igniter into motor and cap with igniter plug, making sure to space leads
      3. Install the motor in an adapter
      4. Insert D spacer ring into the motor mount
      5. Insert the motor assembly into the motor mount so a notch from the adapter lines up with the clip on the motor mount so it clicks into place
    2. D Motors
      1. Attach thermocouple(s)
      2. Insert igniter into motor and cap with igniter plug, making sure to space leads
      3. Insert D spacer ring into the motor mount
      4. Insert the motor into the motor mount, pushing it all the way into the the motor mount, note the clip should close
    3. E Motors
      1. Attach thermocouple(s)
      2. Insert igniter into motor and cap with igniter plug, making sure to space leads
      3. Insert the motor into the motor mount, pushing it all the way into the the motor mount, note the clip should close
  5. Double check that the range is actually clear
  6. Set up igniter
    1. Make sure the firing pin is not in place
    2. Connect alligator clips from Launch Controller to the igniter (one to each lead)
      1. At this point the range is hot (ready to fire)

Perform Test (Fire Motor and Take Data)*

  1. Hit button to Enable Recording
  2. Insert firing pin into Launch Controller
  3. Check for continuity by pressing on firing pin (light will turn on)
  4. Count down
  5. Press ignition button (may have to hold it down for a second)
  6. At the end of the firing, remove the firing pin from the Launch Controller

Post Test Duties*

  1. Remove motor and prepare for disposal
    1. Wait several minutes before removing the motor to allow it to cool down to a safe handling temperature
    2. Remember to also remove the D space ring if the motor was D size or smaller
    3. Remember to find the igniter (it should still be attached to the alligator clips) so it can be properly disposed
    4. For C size motors and smaller, be sure to recover the motor adapter
    5. Store spent motors away from flammable material during future tests
  2. Check to make sure that data was autosaved to the "data" directory.
  3. Click the Clear button on the software once you have finished viewing the data.

Post Operations Duties (After Firing All Motors)

  1. Dispose of motor(s), being careful to observe all state, federal, and local guidelines.
    1. Rinse motors in water to ensure they are completely cooled before disposal
    2. Throw the motors away according the manufacturer’s recommendation
  2. Pack up the accessories
  3. Pack up the computer
  4. Pack up the test stand and block

Note: If performing multiple tests during the same setup, repeat the steps with an asterisk (*) for each test.

Software Operation

For instructions on how to download and install the Shepard data acquisition (DAQ) software, please see the Software Source Code section of the wiki.

Wiring (Arduino) Software

Inside the ShepardDCS_Arduino directory within the repository (/trunk/ShepardDCS/ShepardDCS_Arduino), you will find the ShepardDCS_Arduino.ino file. Before this file can be opened and run using the Arduino IDE, there is a third-party library from Adafruit that must be installed for the MAX31855 thermocouple amplifier breakout board. The library should already be included in the trunk/libraries directory, but if it's not, the library can be downloaded from Github here , and instructions to install the library are included under the "Arduino Library" section here . To make sure that the library gets inluded, set the shepard-ts/trunk directory to be the Sketchbook location under File -> Preferences in the Arduino IDE.

Processing (Desktop) Software

When you've downloaded the source code via subversion, you descend through the directory tree until you end up in the ShepardDCS directory (see Listing 1). Inside this directory you will find a directory holding the Arduino code, and one holding the Processing (PC-side) code. There is a file named ShepardDCS_Arduino.ino inside the ShepardDCS_Arduino directory. You open this file with the Arduino IDE and compile/upload it to the Arduino Uno. The ShepardDCS_Processing directory includes the ShepardDCS_Processing.pde file, which you open and run with the Processing IDE on your PC to display the data dashboard for Shepard.

Listing 1

├── branches
├── tags
└── trunk
    ├── libraries
    │   └── controlP5
    └── ShepardDCS
        ├── ShepardDCS_Arduino
        └── ShepardDCS_Processing

You'll notice that there is a libraries directory at the same level as the ShepardDCS directory. libraries contains the ControlP5 library which provides the graphical elements for the ShepardDCS user interface. In order for this library to be found, you will either need to move the libraries directory into the already configured Processing sketchbook directory, or you'll have to reconfigure the sketchbook directory to point to the trunk directory. This option is found under File -> Preferences in the Processing IDE (Figure 1 and Figure 2).

Figure 1

Figure 2

Once you're connected the PC to the Arduino Uno with a USB cable, open and run the ShepardDCS_Arduino.ino file from the Arduino IDE first. This will load and start the program on the Uno. When the Arduino program is running and ready to transmit data, the TX LED for the serial port will be lighted continuously.

Start the Processing application and the TX LED on the Arduino Uno should start to flash. If you have the sensors attached, you should be able to apply pressure to the thrust sensor to change the "CUR" (current thrust value) slide on the user interface as a simple test. To check temperature monitoring, you can hold the thermocouple between your thumb and index finger to see if the "CUR" value for the temperature rises.

There are several components of the user interface, and those are numbered for reference in Figure 3.

Figure 3

  1. The SERIAL PORT dropdown box allows you to set the serial port that the Arduino is attached to. This dropdown box will be populated with the serial ports (including the Arduino) that are attached to your system. For Windows it will be a serial port designation such as "COM5", and for Linux it will be something like /dev/ttyACM0 . Linux users may have to add themselves to a group that has access to serial ports such as dialout.
  2. The text that you enter in the MOTOR MODEL field will be prepended to the output file name. The rest of the file name will consist of a time stamp. For instance, if you enter "B1-6" in the MOTOR MODEL text field and then record data at 8:42:38 AM, you will end up with a file name of B1-6_8_42_32.csv. If you leave this field blank the file name will start with an underscore followed by the time stamp (_8_42_32.csv).
  3. The ENABLE RECORDING button allows you to control whether or not the application keeps track of the thrust and temperature on the chart, and the max/peak and average sliders. This button also controls whether or not the data is written to a CSV file. When this button is enabled (clicked so that it becomes highlighted) and the thrust value goes above a value of 0.0, data will be collected. Once the ENABLE RECORDING button is disabled (clicked so that it is no longer highlighted) and the thrust value has been above 0.0, the data will be written to a file.
  4. The CLEAR button clears the charts, averages, and maxes to prepare for the next run. Do not click this until you are finished looking at the data from the previous test.
  5. The Thrust chart has Newtons (N) on the Y-axis, and time on the X-axis. The X-axis will auto scale as the time (seconds) increases, and new values feed from the right side to the left side of the chart.
  6. The CUR (current value) sliders provide a graphical and numeric representation of either the thrust (top slider), or the temperature (bottom slider). The slider will fill from the bottom to the top as the value increases.
  7. The PEAK or MAX value sliders show the same thing, but different terminology is used for the thrust (PEAK) than for the temperature (MAX). Both of these sliders show the highest value that is reached during a test run. This is either the peak thrust of the motor, or the highest temperature that was seen on the motor casing.
  8. The AVG (average) sliders keep track of a running average of the values reported by the thrust and temperature sensors. This average is influenced by how long you leave the ENABLE RECORDING button enabled (clicked so that it is highlighted), so it's best to stop the recording soon after the motor has exhausted its fuel and ejected the parachute charge.
  9. The Temperature chart works in the same way as the Thrust chart above. The Y-axis is in degrees Celsius (C), and the X-axis is again in seconds. The X-axis auto-scales as time increases, and new values feed from the right side of the chart to the left.

For a normal test run, you would follow all of the steps shown in "Hardware Operation" above. Two software related items that are called out is clicking the Enable Recording button and clicking the Clear button. If the Enable Recording button is not clicked when you preform a test run, you will only see the current value slider change, and no data will be recorded. On the other hand, you do not want the Enable Recording button to be clicked/enabled when you're testing sensors or you may end up with a false trigger and useless data. Keep the Enable Recording button toggled to disabled until you're ready to perform a test fire. Failure to click the Clear button before doing another test run will cause the new data to be combined with the old data, causing tandem curves on the charts, and incorrect averages and maxes.

The test stand's data is stored in CSV (comma delimited) format, so you can copy the files to any computer to perform an analysis. Applications like Microsoft Office and Libre Office will allow you to create line charts and do much more with the data.

Integrated Operation

Once the third-party library is installed, you should be able to compile and upload the Arduino program. You can then close the Arduino IDE, restart the Arduino Uno, and launch the Processing app to start collecting the data.

Operating Manual v1.0

This document has been relinked to the Operating Manual document here as part of our versioning system update.

Hardware Operation

Unpacking After Transport

  1. Check shipping container(s) for:
    1. Test stand
    2. Concrete block
    3. Box of accessories
      1. Launch controller
      2. D motor spacer ring
      3. Motor mount adapters (A, B, and C to D/E size)
      4. Thermocouple attachment tape (high temp)
    4. Computer and USB cable
    5. Motors to test (with igniters and igniter plugs)
    6. Fire extinguisher and maybe a bucket for water

Test Stand Setup

  1. Place concrete block in location where test stand will be operated
  2. Set test stand on concrete block
  3. Create the safety perimeter.
    1. Delineate no stand zone for both proximity and positions
      1. Use length of cord for the igniter (radius of operations)
      2. Exclusion zones exist behind where exhaust escapes (30 degree cone), and in front on each side of the exhaust T (30 degree cone on each side)
  4. Set up the management area for test.
    1. Igniter
      1. Clip the igniter to a part of the test stand and deploy the cable to its full length and place it where the test(s) will be run from
    2. Computer
      1. Set up computer
      2. Boot computer
      3. Run USB cable from computer to test stand
      4. Connect Arduino-based DAQ system to USB cable at test stand
      5. Start the Test Stand App
      6. Ensure DAQ system and Computer are both running and connected

Prepare For Test*

  1. Check the following areas of the test stand for fatigue damage and good fit.
    1. Motor mount
    2. Zip ties holding motor mount
    3. Linear guide rail system
  2. Clear any debris from linear guide rail system and ejection charge exhaust ports
  3. Test sensors
    1. Push on thrust sensor and confirm current value slider responds
    2. Put fingers around thermocouple(s) (after ensuring it is not hot) and confirm plot responds
  4. Install motor in test stand
    1. A-C Motors
      1. Attach thermocouple(s)
      2. Insert igniter into motor and cap with igniter plug, making sure to space leads
      3. Install the motor in an adapter
      4. Insert D spacer ring into the motor mount
      5. Insert the motor assembly into the motor mount so a notch from the adapter lines up with the clip on the motor mount so it clicks into place
    2. D Motors
      1. Attach thermocouple(s)
      2. Insert igniter into motor and cap with igniter plug, making sure to space leads
      3. Insert D spacer ring into the motor mount
      4. Insert the motor into the motor mount, pushing it all the way into the the motor mount, note the clip should close
    3. E Motors
      1. Attach thermocouple(s)
      2. Insert igniter into motor and cap with igniter plug, making sure to space leads
      3. Insert the motor into the motor mount, pushing it all the way into the the motor mount, note the clip should close
  5. Double check that the range is actually clear
  6. Set up igniter
    1. Make sure the firing pin is not in place
    2. Connect alligator clips from Launch Controller to the igniter (one to each lead)
      1. At this point the range is hot (ready to fire)

Perform Test (Fire Motor and Take Data)*

  1. Hit button to Enable Recording
  2. Insert firing pin into Launch Controller
  3. Check for continuity by pressing on firing pin (light will turn on)
  4. Count down
  5. Press ignition button (may have to hold it down for a second)
  6. At the end of the firing, remove the firing pin from the Launch Controller

Post Test Duties*

  1. Remove motor and prepare for disposal
    1. Wait several minutes before removing the motor to allow it to cool down to a safe handling temperature
    2. Remember to also remove the D space ring if the motor was D size or smaller
    3. Remember to find the igniter (it should still be attached to the alligator clips) so it can be properly disposed
    4. For C size motors and smaller, be sure to recover the motor adapter
    5. Store spent motors away from flammable material during future tests
  2. Check to make sure that data was autosaved to the "data" directory.
  3. Click the Clear button on the software once you have finished viewing the data.

Post Operations Duties (After Firing All Motors)

  1. Dispose of motor(s), being careful to observe all state, federal, and local guidelines.
    1. Rinse motors in water to ensure they are completely cooled before disposal
    2. Throw the motors away according the manufacturer’s recommendation
  2. Pack up the accessories
  3. Pack up the computer
  4. Pack up the test stand and block

Note: If performing multiple tests during the same setup, repeat the steps with an asterisk (*) for each test.

Software Operation

For instructions on how to download and install the Shepard data acquisition (DAQ) software, please see the Software Source Code section of the wiki.

Wiring (Arduino) Software

Inside the ShepardDCS_Arduino directory within the repository (/trunk/ShepardDCS/ShepardDCS_Arduino), you will find the ShepardDCS_Arduino.ino file. Before this file can be opened and run using the Arduino IDE, there is a third-party library from Adafruit that must be installed for the MAX31855 thermocouple amplifier breakout board. The library should already be included in the trunk/libraries directory, but if it's not, the library can be downloaded from Github here , and instructions to install the library are included under the "Arduino Library" section here . To make sure that the library gets inluded, set the shepard-ts/trunk directory to be the Sketchbook location under File -> Preferences in the Arduino IDE.

Processing (Desktop) Software

When you've downloaded the source code via subversion, you descend through the directory tree until you end up in the ShepardDCS directory (see Listing 1). Inside this directory you will find a directory holding the Arduino code, and one holding the Processing (PC-side) code. There is a file named ShepardDCS_Arduino.ino inside the ShepardDCS_Arduino directory. You open this file with the Arduino IDE and compile/upload it to the Arduino Uno. The ShepardDCS_Processing directory includes the ShepardDCS_Processing.pde file, which you open and run with the Processing IDE on your PC to display the data dashboard for Shepard.

Listing 1

├── branches
├── tags
└── trunk
    ├── libraries
    │   └── controlP5
    └── ShepardDCS
        ├── ShepardDCS_Arduino
        └── ShepardDCS_Processing

You'll notice that there is a libraries directory at the same level as the ShepardDCS directory. libraries contains the ControlP5 library which provides the graphical elements for the ShepardDCS user interface. In order for this library to be found, you will either need to move the libraries directory into the already configured Processing sketchbook directory, or you'll have to reconfigure the sketchbook directory to point to the trunk directory. This option is found under File -> Preferences in the Processing IDE (Figure 1 and Figure 2).

Figure 1

Figure 2

Once you're connected the PC to the Arduino Uno with a USB cable, open and run the ShepardDCS_Arduino.ino file from the Arduino IDE first. This will load and start the program on the Uno. When the Arduino program is running and ready to transmit data, the TX LED for the serial port will be lighted continuously.

Start the Processing application and the TX LED on the Arduino Uno should start to flash. If you have the sensors attached, you should be able to apply pressure to the thrust sensor to change the "CUR" (current thrust value) slide on the user interface as a simple test. To check temperature monitoring, you can hold the thermocouple between your thumb and index finger to see if the "CUR" value for the temperature rises.

There are several components of the user interface, and those are numbered for reference in Figure 3.

Figure 3

  1. The SERIAL PORT dropdown box allows you to set the serial port that the Arduino is attached to. This dropdown box will be populated with the serial ports (including the Arduino) that are attached to your system. For Windows it will be a serial port designation such as "COM5", and for Linux it will be something like /dev/ttyACM0 . Linux users may have to add themselves to a group that has access to serial ports such as dialout.
  2. The text that you enter in the MOTOR MODEL field will be prepended to the output file name. The rest of the file name will consist of a time stamp. For instance, if you enter "B1-6" in the MOTOR MODEL text field and then record data at 8:42:38 AM, you will end up with a file name of B1-6_8_42_32.csv. If you leave this field blank the file name will start with an underscore followed by the time stamp (_8_42_32.csv).
  3. The ENABLE RECORDING button allows you to control whether or not the application keeps track of the thrust and temperature on the chart, and the max/peak and average sliders. This button also controls whether or not the data is written to a CSV file. When this button is enabled (clicked so that it becomes highlighted) and the thrust value goes above a value of 0.0, data will be collected. Once the ENABLE RECORDING button is disabled (clicked so that it is no longer highlighted) and the thrust value has been above 0.0, the data will be written to a file.
  4. The CLEAR button clears the charts, averages, and maxes to prepare for the next run. Do not click this until you are finished looking at the data from the previous test.
  5. The Thrust chart has Newtons (N) on the Y-axis, and time on the X-axis. The X-axis will auto scale as the time (seconds) increases, and new values feed from the right side to the left side of the chart.
  6. The CUR (current value) sliders provide a graphical and numeric representation of either the thrust (top slider), or the temperature (bottom slider). The slider will fill from the bottom to the top as the value increases.
  7. The PEAK or MAX value sliders show the same thing, but different terminology is used for the thrust (PEAK) than for the temperature (MAX). Both of these sliders show the highest value that is reached during a test run. This is either the peak thrust of the motor, or the highest temperature that was seen on the motor casing.
  8. The AVG (average) sliders keep track of a running average of the values reported by the thrust and temperature sensors. This average is influenced by how long you leave the ENABLE RECORDING button enabled (clicked so that it is highlighted), so it's best to stop the recording soon after the motor has exhausted its fuel and ejected the parachute charge.
  9. The Temperature chart works in the same way as the Thrust chart above. The Y-axis is in degrees Celsius (C), and the X-axis is again in seconds. The X-axis auto-scales as time increases, and new values feed from the right side of the chart to the left.

For a normal test run, you would follow all of the steps shown in "Hardware Operation" above. Two software related items that are called out is clicking the Enable Recording button and clicking the Clear button. If the Enable Recording button is not clicked when you preform a test run, you will only see the current value slider change, and no data will be recorded. On the other hand, you do not want the Enable Recording button to be clicked/enabled when you're testing sensors or you may end up with a false trigger and useless data. Keep the Enable Recording button toggled to disabled until you're ready to perform a test fire. Failure to click the Clear button before doing another test run will cause the new data to be combined with the old data, causing tandem curves on the charts, and incorrect averages and maxes.

The test stand's data is stored in CSV (comma delimited) format, so you can copy the files to any computer to perform an analysis. Applications like Microsoft Office and Libre Office will allow you to create line charts and do much more with the data.

Integrated Operation

Once the third-party library is installed, you should be able to compile and upload the Arduino program. You can then close the Arduino IDE, restart the Arduino Uno, and launch the Processing app to start collecting the data.

Shepard Test Stand Preliminary Design v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Introduction

The preliminary design discussion is broken down into two parts in the forums.

  1. Mechanical systems
  2. Data Acquisition (DAQ) Systems

Most of this preliminary design work was done via Google+ Hangout. The meeting minutes from those hangouts will be distilled down into a form suitable for this document, but in the meantime you can find links to the raw meeting minutes below. You will most likely need to request permission to view the document.

  1. Mechanical Hangout Minutes
  2. Data Acquisition Hangout Minutes

A full list of all the meeting minutes pertaining to Shepard can be found here

Preliminary Mechanical Design

You can refer back to the version 1.0 preliminary design items STSPM 2.2 through STSPM 2.4.3 for competing design choices for the structure.

Preliminary Data Acquisition Design

Shepard Test Stand Preliminary Design v1.0

This document has been relinked to the Preliminary Design document here as part of our versioning system update.

Introduction

The preliminary design discussion is broken down into two parts in the forums.

  1. Mechanical systems
  2. Data Acquisition (DAQ) Systems

Most of this preliminary design work was done via Google+ Hangout. The meeting minutes from those hangouts will be distilled down into a form suitable for this document, but in the meantime you can find links to the raw meeting minutes below. You will most likely need to request permission to view the document.

  1. Mechanical Hangout Minutes
  2. Data Acquisition Hangout Minutes

Note: Need to get all of the minutes linked here

Preliminary Mechanical Design

Preliminary Mechanical Cost Estimates (For One-Off Quantities)
Item Cost (Shipping to Midwest U.S.) Approx Total Link
8' 2x10 pine board $7.75 $7.75
8' 2x4 pine board $2.50 $2.50
4"x8"x16" solid concrete block $1.50 $1.50
Small Ball Bearing Drawer Guide $6.00 $6.00
Pulley $3.00 $3.00
Estes D/E Motor Mount $9.00 $9.00 http://bit.ly/Rrn330
Estes Motor Adapters $6.00 $6.00 http://bit.ly/MYMnNg
Copper T-Fitting $3.00 $3.00
High Heat Spray Primer $8.00 $8.00
High Heat Spray Paint $5.00 $5.00
Misc Hardware $5.00 $5.00
Total $56.75

Note: Need to address shielding in the cost table above.

Preliminary Data Acquisition Design

Preliminary DAQ Cost Estimates (For One-Off Quantities)
Item Cost (Shipping to Midwest U.S.) Approx Total Link
Arduino Uno R3 $29.95 + shipping $35 http://bit.ly/N5kizl
1.5 Inch Square FSR $7.95 + shipping $16 http://bit.ly/Pd3ztz
TLV2374 Op Amp $1.71 + shipping $8 http://bit.ly/OcVA12
560 Ohm Resistor x 2 $0.20 (combined w/ shipping above) $0.20 http://bit.ly/M3duBJ
Type-K Glass Braid Insulated Thermocouple $10.00 + shipping $13.87 http://bit.ly/NPRosE
Adafruit Thermocouple Amplifier $17.50 + shipping $21.50 http://bit.ly/OqVc2A
Misc (Wire, etc) $5.00
Total $99.57

Shepard Test Stand Procurement v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Mechanical System

All of the items in the mechanical system are described on the wiki , and detailed information including measurements can be found in the BoM .

Data Acquisition (DAQ) System

The items in the DAQ system are described on the wiki .

Shepard Test Stand Procurement/Manufacture

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Mechanical System

All of the items in the mechanical system are described on the wiki , and detailed information including measurements can be found in the BoM .

Data Acquisition (DAQ) System

The items in the DAQ system are described on the wiki .

Procurement/Manufacture v1.0

This document has been relinked to the Procurement/Manufacture document here as part of our versioning system update.

Mechanical System

All of the items in the mechanical system are described on the wiki , and detailed information including measurements can be found in the BoM .

Data Acquisition (DAQ) System

The items in the DAQ system are described on the wiki .

Shepard Test Stand Requirements Document v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Introduction

The requirements list matches up to the Initial Questions in step one of the Systems Engineering process as shown below. Each requirement is labeled with STSR (Shepard Test Stand Requirement), followed by the number of the initial question that the requirement corresponds to, followed by a dot and then the ID number of the requirement.

Technical Requirements

Technical requirements are those requirements which include measurable performance values. Each technical requirement should be verified through testing to ensure the design meets the requirement.

Project Requirements

Project requirements are the remaining requirements which are not tied to specific performance values.

Future Requirements

These are for reference only so that future features can be accommodated in the current design where practical.

The accommodation of:

Glossary

ADC - Analog to Digital Converter
consumables - Items that are used and then discarded, i.e. rocket motors.
IAW - In Accordance With
LSB - Least Significant Bit
NAR - National Association of Rocketry
STS - Shepard Test Stand
STSR - Shepard Test Stand Requirement

Shepard Test Stand Requirements Document v1.0

This document has been relinked to the Requirements Document here as part of our versioning system update.

Introduction

This requirements document is currently being discussed on the forums here. The requirements list matches up to the Initial Questions in step one of the Systems Engineering process as shown below. Each requirement is labeled with STSR (Shepard Test Stand Requirement), followed by the number of the initial question that the requirement corresponds to, followed by a dot and then the ID number of the requirement.

Technical Requirements

Technical requirements are those requirements which include measurable performance values. Each technical requirement should be verified through testing to ensure the design meets the requirement.

Project Requirements

Project requirements are the remaining requirements which are not tied to specific performance values.

Future V2.0 Requirements

These are for reference only so that future features can be accommodated in the current design where practical.

Version 2.0: Beyond Version 2.0 (Accommodation of):

Glossary

ADC - Analog to Digital Converter
consumables - Items that are used and then discarded, i.e. rocket motors.
IAW - In Accordance With
LSB - Least Significant Bit
NAR - National Association of Rocketry
STS - Shepard Test Stand
STSR - Shepard Test Stand Requirement

Gelled: 2012-05-28 v47

Shepard Test Stand Safety Procedures v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Introduction

This document includes procedures that are designed to ensure the safe operation of the Shepard Test Stand. Each safety procedure item is labeled with a prefix of "STSSP", which stands for "Shepard Test Stand Safety Procedure". This prefix is followed by the number of the main section (i.e. 1), which is then followed by the number of the specific item (i.e. x.1). This is done so that the procedures are easy to reference for training purposes or to point out a specific safety violation.

Safety Procedures

Figures

Figure 2.4

Glossary

NAR - National Association of Rocketry
STSSP - Shepard Test Stand Safety Procedure

Safety Procedures v1.0

This document has been relinked to the Safety Procedures document here as part of our versioning system update.

Introduction

This document includes procedures that are designed to ensure the safe operation of the Shepard Test Stand. Each safety procedure item is labeled with a prefix of "STSSP", which stands for "Shepard Test Stand Safety Procedure". This prefix is followed by the number of the main section (i.e. 1), which is then followed by the number of the specific item (i.e. x.1). This is done so that the procedures are easy to reference for training purposes or to point out a specific safety violation.

Safety Procedures

Figures

Figure 2.4

Glossary

NAR - National Association of Rocketry
STSSP - Shepard Test Stand Safety Procedure

Shepard Test Stand Schematics and PCB Files v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

There are no PCB files for this version of the Shepard Test Stand at this time.

You can find the schematic files in the DMSF plugin here

An image of the schematic is shown in Figure 1.

Figure 1

Schematics and PCB Files v1.0

This document has been relinked to the Schematics and PCB Files document here as part of our versioning system update.

There are no PCB files for this version of the Shepard Test Stand at this time.

You can find the schematic files in the DMSF plugin here

An image of the schematic is shown in Figure 1.

Figure 1

Navigation

Shepard Test Stand

Documentation

  1. BOM
  2. Schematics and PCB Files
  3. Software Source Code
  4. Assembly Instructions
  5. Operating Manual
  6. Safety Procedures
  7. Software/Firmware Summary
  8. Errata

Systems Engineering Process

  1. Initial Questions
  2. Requirements Document
  3. Block Diagram
  4. Budget
  5. Timeline
  6. Preliminary Design
  7. Detailed Design
  8. Design Review
  9. Procurement
  10. Manufacture
  11. Assembly
  12. Integration
  13. Testing
  14. Disposal
  15. Development Logs
  16. Meeting Minutes

Shepard Test Stand Software and Firmware Summary v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

The software for the test stand consists of two main components:
  1. The Processing software that runs on the laptop or desktop computer.
  2. The Arduino Wiring software that runs on the Arduino Uno.

Processing (Desktop) Software

Contained within /trunk/ShepardDCS/ShepardDCS_Processing in the repository, this software is responsible for receiving the data from the Arduino and displaying it for the user. In order to run, the code depends on the controlP5 library that is in /trunk/libraries/controlP5 . This must be installed according to the instructions found here before the desktop software will run. The software is not designed to run stand-alone in the current iteration, and instead is run through the Processing Integrated Development Environment (IDE).

Wiring (Arduino) Software

Contained within /trunk/ShepardDCS/ShepardDCS_Arduino in the repository, this software runs on the Arduino and is responsible for collecting the sensor data and sending it to the Processing desktop application. The Arduino software requires the installation of a third-party library from Adafruit for the MAX31855 thermocouple amplifier. You can find those installation instructions here

Software and Firmware Summary v1.0

This document has been relinked to the Software and Firmware Summary document here as part of our versioning system update.

The software for the test stand consists of two main components:
  1. The Processing software that runs on the laptop or desktop computer.
  2. The Arduino Wiring software that runs on the Arduino Uno.

Processing (Desktop) Software

Contained within /trunk/ShepardDCS/ShepardDCS_Processing in the repository, this software is responsible for receiving the data from the Arduino and displaying it for the user. In order to run, the code depends on the controlP5 library that is in /trunk/libraries/controlP5 . This must be installed according to the instructions found here before the desktop software will run. The software is not designed to run stand-alone in the current iteration, and instead is run through the Processing Integrated Development Environment (IDE).

Wiring (Arduino) Software

Contained within /trunk/ShepardDCS/ShepardDCS_Arduino in the repository, this software runs on the Arduino and is responsible for collecting the sensor data and sending it to the Processing desktop application. The Arduino software requires the installation of a third-party library from Adafruit for the MAX31855 thermocouple amplifier. You can find those installation instructions here

Misc Software

There are several development programs here which represent the early stages of the Shepard v1.0 software development process. Some of this code may still be useful for reference or things like manual calibration.

Shepard Test Stand Software Source Code v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

In order to download the latest source code for the data acquisition (DAQ) software, you will need a subversion client.

Please be aware that the newest versions of Shepard DCS will not work with this version of the Shepard DAQ. You'll want to check out version 22 instead.

On Linux, you can install the subversion package and then execute the following on a command line.

svn co https://opendesignengine.net/svn/shepard-ts

This will download the source tree to the current directory. The top level directory will be shepard-ts and the most current version will be in the trunk directory.

There will also be milestone versions available for download from DMSF . These versions will not necessarily be up-to-date though.

For instructions on how to use the software, please see the Operating Manual

Software Source Code v1.0

This document has been relinked to the Software Source Code document here as part of our versioning system update.

In order to download the latest source code for the data acquisition (DAQ) software, you will need a subversion client.

On Linux, you can install the subversion package and then execute the following on a command line.

svn co https://opendesignengine.net/svn/shepard-ts

This will download the source tree to the current directory. The top level directory will be shepard-ts and the most current version will be in the trunk directory.

There will also be milestone versions available for download from DMSF . These versions will not necessarily be up-to-date though.

For instructions on how to use the software, please see the Operating Manual

Shepard Test Stand Testing v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

There was no formal testing done on version 1.1. However, work was done to ensure that the replacement Force Sensing Resistor (FSR) increased the effective range of the thrust measurement.

The testing was done in three main phases, with the first two progressing in parallel:
  1. The mechanical system was tested as a stand-alone unit.
  2. The Data Acquisition (DAQ) system was tested as a stand-alone unit.
  3. The mechanical and DAQ systems were integrated and then tested.

Mechanical System Testing

Below are several videos taken during the initial mechanical tests of the test stand by J. Simmons at Dayton Diode in Dayton, Ohio.

DAQ System Testing

During DAQ System testing, it was discovered that the data collection rate of the system was much too low, being around 15 samples per second. This is due to the fact that the MAX31855 thermocouple amplifier takes between 70 and 100 milliseconds to convert its reading.

Integrated Testing

During the integrated testing, 2 more flaws were discovered in the design.

  1. The drawer guide used as the linear rail for the motor mount tended to foul within 30 to 50 test firings due to the fact the ball bearings were exposed to the motor exhaust particulates. Figure 1 shows the fouling.
  2. The Force Sensing Resistor (FSR) that was specified for the test stand was not capable of registering anything higher than 10 Newtons of force. This puts some of the higher thrust motors beyond the range that the FSR can measure.

Figure 1 - Fouling of the Drawer Guide's Bearings By Exhaust Particulates

It was also realized before the first test firing that the motor mount contact pad would have to be added. This was to ensure that the thrust of the motor was spread over the entire sensing surface of the FSR and not beyond into the substrate border.

Below are several raw videos taken during the integration tests of the test stand by J. Simmons and Jeremy Wright at Club Cyberia in Indianapolis, Indiana.

There is a safety violation in the following video when Jeremy enters one of the "Cones of Exclusion" within the range. This should be taken as an example of what not to ever do. Make sure to follow the Shepard safety procedures to prevent injury and fire during a test.

Testing v1.0

This document has been relinked to the Testing document here as part of our versioning system update.

The testing was done in three main phases, with the first two progressing in parallel:
  1. The mechanical system was tested as a stand-alone unit.
  2. The Data Acquisition (DAQ) system was tested as a stand-alone unit.
  3. The mechanical and DAQ systems were integrated and then tested.

Mechanical System Testing

Below are several videos taken during the initial mechanical tests of the test stand by J. Simmons at Dayton Diode in Dayton, Ohio.

DAQ System Testing

During DAQ System testing, it was discovered that the data collection rate of the system was much too low, being around 15 samples per second. This is due to the fact that the MAX31855 thermocouple amplifier takes between 70 and 100 milliseconds to convert its reading.

Integrated Testing

During the integrated testing, 2 more flaws were discovered in the design.

  1. The drawer guide used as the linear rail for the motor mount tended to foul within 30 to 50 test firings due to the fact the ball bearings were exposed to the motor exhaust particulates. Figure 1 shows the fouling.
  2. The Force Sensing Resistor (FSR) that was specified for the test stand was not capable of registering anything higher than 10 Newtons of force. This puts some of the higher thrust motors beyond the range that the FSR can measure.

Figure 1 - Fouling of the Drawer Guide's Bearings By Exhaust Particulates

It was also realized before the first test firing that the motor mount contact pad would have to be added. This was to ensure that the thrust of the motor was spread over the entire sensing surface of the FSR and not beyond into the substrate border.

Below are several raw videos taken during the integration tests of the test stand by J. Simmons and Jeremy Wright at Club Cyberia in Indianapolis, Indiana.

There is a safety violation in the following video when Jeremy enters one of the "Cones of Exclusion" within the range. This should be taken as an example of what not to ever do. Make sure to follow the Shepard safety procedures to prevent injury and fire during a test.

Shepard Test Stand Timeline v1.1

This is a newer document based on this one , and you should refer to that original version if you want to see the revision history.

Overview

The goal is to complete the project within three months of formal launch as an exercise of agile design. However, given the project is also an experiment in open source hardware development and is all volunteer based, we need to recognize the need to be flexible in this requirement.

See the Gantt chart if you would like to track the progress of this project. The best way to see the entire timeline of the project is to set the Status pull down menu to All, and set the filters to be 12 months from May 2012 (Figure 1). Then click "Apply".

Figure 1 - Filter Settings to See the Complete Shepard v1.0 Timeline

Timeline v1.0

This document has been relinked to the Timeline document here as part of our versioning system update.

Overview

The goal is to complete the project within three months of formal launch as an exercise of agile design. However, given the project is also an experiment in open source hardware development and is all volunteer based, we need to recognize the need to be flexible in this requirement.

See the Gantt chart if you would like to track the progress of this project. The best way to see the entire timeline of the project is to set the Status pull down menu to All, and set the filters to be 12 months from May 2012 (Figure 1). Then click "Apply".

Figure 1 - Filter Settings to See the Complete Shepard v1.0 Timeline

v1.0 Shepard Test Stand - Prototype

This version of the test stand is a prototype to not only teach us about the fundamentals of building a rocket motor test stand, but also about the process of building spaceflight related hardware with a geographically distributed team. Many lessons were learned in this version that will be rolled into future versions of Shepard and beyond.

Shepard Test Stand Version 1.0

Documentation - Version 1.0

  1. BOM
  2. Schematics and PCB Files
  3. Software Source Code
  4. Assembly Instructions
  5. Operating Manual
  6. Safety Procedures
  7. Software/Firmware Summary
  8. Errata

Systems Engineering Process - Version 1.0

  1. Initial Questions
  2. Requirements Document
  3. Block Diagram
  4. Budget
  5. Timeline
  6. Preliminary Design
  7. Detailed Design
  8. Design Review
  9. Procurement_Manufacture
  10. Assembly
  11. Integration
  12. Testing
  13. Disposal
  14. Meeting Minutes

V1.1 Description

The second iteration of the Shepard rocket motor test stand. This is an incremental update over 1.0 where only the major issues are fixed, and the requirements are scaled back appropriately for the level of the project.

There was a little bit of a process breakdown on this version, so some version 2.0 DAQ documentation got mixed in with the version 1.1 docs. Because of this, the wiki and dev logs may be a little hard to follow but have been cleaned up as much as possible.

Please refer instead to the Shepard v2.0 documentation to make sure that you are building the latest iteration.

Shepard Test Stand Version 1.1

Documentation - Version 1.1

  1. BOM
  2. Schematics and PCB Files
  3. Software Source Code
  4. Assembly Instructions
  5. Operating Manual
  6. Safety Procedures
  7. Software/Firmware Summary
  8. Errata

Systems Engineering Process - Version 1.1

  1. Initial Questions
  2. Requirements Document
  3. Block Diagram
  4. Budget (The 1.5 inch square FSR should have been replaced with this 1.0 inch round version )
  5. Timeline
  6. Preliminary Design
  7. Detailed Design
  8. Design Review
  9. Procurement
  10. Manufacture
  11. Assembly
  12. Integration
  13. Testing
  14. Disposal
  15. Meeting Minutes

Versions

v1.0 Description Documentation
v1.1 Description Documentation
v2.0 Description Documentation

Shepard Test Stand Wiki v2.0

Introduction

Welcome to the project Wiki for the Mach 30 Shepard Test Stand. This test stand holds small model rocket motors fixed (clamped in place) during firings so that things like thrust and casing temperature can be measured. This wiki contains documentation covering the design, development, fabrication, and use of the test stand.

The Shepard Test Stand is named after Alan Shepard, America's first astronaut, as it is our first test stand. We are using an Arduino board to provide the physical interface between the data collecting computer and the required sensors. This project is the first in a series of projects to develop the required skills for the practice of safe rocket engine operation, and to develop the capability to measure and record data about a rocket engine's performance. The idea behind the Shepard Test Stand project is to start small and simple, and then build on what is learned when moving to larger and more complex stands later on. This is very much in keeping with Mach 30's philosophy of starting (literally) from the ground up to build the infrastructure required to facilitate safe, routine, reliable, and sustained access to space. The second iteration of Shepard only measured the thrust and motor casing temperature of Estes model rocket motors sized A through E. This third iteration (v2.0) will step beyond that to offer higher resolution measurements and an easier to assemble structure, among other things. The Shepard project is structured in a way that should allow anyone to build and improve upon the designs. Everyone from experienced space flight hardware designers to educators and students are encouraged to get involved with the project and share their knowledge and enthusiasm.

If you're interested in getting involved, please introduce yourself in the forums and let us know what your interests and specialties are. There is also the navigation bar at the right to help you browse the documentation to get up-to-speed.

Shepard for Teachers and Scout Leaders

We are currently working with a partner organization, the Coca-Cola Space Science Center to develop curriculum so that Shepard can be used in middle school, high school, and college classrooms. In addition, we intend to have Shepard Test Stand kits available for sale sometime in the first half of 2014. If you're interested in finding out more about Shepard in education, please contact Mach 30 . If you're planning to build and operate a Shepard Test Stand on your own, please start by reading the Safety Procedures.

Shepard for Makers

Mach 30 believes that Makers and Makerspaces will be a large part of the new spacefaring workforce, partnering with us in our mission "[t]o hasten the advancement of humanity into a spacefaring civilization through sustainable leadership, open design practices, and a bias toward mature technology." If that sounds like something you want to be involved in, we encourage you to jump right in. If you want to start with our design rationale, take a look at the Systems Engineering Process section in the navigation bar at the right. If building, testing, and operating a test stand is more your speed, start with the Documentation section of the navigation bar. Always make sure to read the Safety Procedures first so that you can have the safest experience possible with Shepard. Also, don't forget to register for an Open Design Engine account so you can start posting to the forums.

Shepard for Students

If you're a student who's ready to start working with Shepard, be sure to start with the Safety Procedures. Once you're up to speed on those, you'll want to take a look at the Operating Manual to learn how to operate the test stand. Any other documentation that you may need should be in the navigation bar at the right under Documentation. Also, don't forget to register for an Open Design Engine account so you can start posting to the forums.

Contributing Makerspaces

A Makerspace located in Indianapolis, Indiana with space (and tools) to collaborate on projects, a training room, a 3D printing area, and much more. Club Cyberia graciously hosted integration testing for versions 1.0 and 1.1 of the Shepard test stand.
Website: http://clubcyberia.org/
A Makerspace located in Dayton, Ohio which is a special interest group (SIG) of the Dayton Microcomputer Association an Ohio 501c(3) non-profit organization. Dayton Diode hosted some of the build sessions for versions 1.0 and 1.1 of the Shepard test stand structure.
Website: http://www.daytondiode.org/