Shepard Test Stand

h1. Shepard Test Stand Preliminary Design v1.0

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h3. Introduction

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

# "Mechanical systems":https://opendesignengine.net/boards/4/topics/158

# "Data Acquisition (DAQ) Systems":https://opendesignengine.net/boards/4/topics/159

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.

# "Mechanical Hangout Minutes":https://docs.google.com/document/d/1M5qMFE-SNDYR_yHCI5XGnKLK1Xq17f7NVWNOhb3XkyU/edit

# "Data Acquisition Hangout Minutes":https://docs.google.com/document/d/1c4HOtpcp2yDxln5aTmMffk5PxDC5d3YM5UA53KJLoi0/edit

h3. Preliminary Mechanical Design

* *STSPM 1.1* We're going to attempt to use "FreeCAD":http://sourceforge.net/apps/mediawiki/free-cad/index.php?title=Main_Page as the base CAD program for this project.

** *STSPM 1.1.1* Files will be stored on "Open Design Engine":opendesignengine.net in the default FreeCAD file format.

** *STSPM 1.1.2* For milestones STL versions will be saved for models, and DXF and PDF formats will be saved for draft files.

* *STSPM 2.1* The frame design will somewhat follow the RepRap family of frames by using threaded rod, smooth rod, and bearings.

** *STSPM 2.1.1* Each end of the frame consists of a triangle of threaded rod with plastic corner caps in a "Mendel assembly":http://reprap.org/wiki/File:Frame-side-assembly.PNG configuration.

** *STSPM 2.1.2* The cross members that tie the two ends of the frame together will be smooth rod, again in the vein of the "Mendel assembly":http://reprap.org/wiki/File:Plumb-1.jpg

** *STSPM 2.1.3* Linear bearings will ride on the smooth rod cross members, and the motor mount carriage will mount to those.

h3. Preliminary Data Acquisition Design

* *STSPD 1.1* A "Force Sensing Resistor":http://www.trossenrobotics.com/c/robot-force-sensor-fsr.aspx will be used for the load cell.

** *STSPD 1.1.1* A "unity gain amplifier":http://banananan.wordpress.com/2012/01/12/pressure-sensor-arduino-processing-signal-analysis/ will be used to obtain measurable output from this sensor.

* *STSPD 1.2* A "type K glass braid insulated thermocouple":http://www.sparkfun.com/products/251 will be used to measure the casing temperature of the motor.

** *STSPD 1.2.1* An Adafruit "thermocouple amplifier":http://www.robotshop.com/productinfo.aspx?pc=RB-Ada-13&lang=en-US will be used to condition the signal for the Arduino's analog inputs.

* *STSPD 1.3* The data will that is recorded by the Arduino will be streamed over the USB connection unless it is found that is not fast enough.

** *STSPD 1.3.1* The data format will consist of a data point coupled with a simple time stamp.

** *STSPD 1.3.2* Data processing will be handled by the computer. This will included the conversion from voltage to force due to the logarithmic nature of the force sensing resistor.

* *STSPD 1.4* The Wiring programming language will be used to program the Arduino, and Processing will be used for any computer-side code.