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Here you can find my documents for the Spring 2016 iteration of 2.77: Fundamentals of Precision Product Design as taught by Prof. Alex Slocum.
PUPS #3
PREP Comments
Write-up
FRDPARRC Table
Problem 6 Model / Calculations
Problem 7a Stick Figure Sketches
Error Apportionment
Error Budgets
Lab 3: Build a 1D linear motion device
Rough CAD Model
My linear motion axis was a basic leadscrew and rod configuration. I used a 5/16"-24 piece of threaded rod for the lead screw, and 2 scrap pieces of 1/2" OD (actually about 0.502" OD) 316SS tubing for the support rods. The carriage was made out of 1" square 6061 extruded rod, and the end blocks were made from 1/2" thick nylon. I did the machining using a EZ-Trak CNC, and was able to hold tolerances to +/-0.001" (which admittedly took longer than I had planned for, but it worked out).
I did some basic testing of the backlash of my axis, and was pleasantly surprised to find that it was just ~0.001" (~25um).
The testing was done by moving the carriage toward one of the end blocks, then measuring the carriage-end block distance with calipers, and then moving the carriage a fixed distance (1 inch) in the opposite direction and remeasuring the carriage-end block distance. I did this several times at different distances and against both end blocks.
Seek and Geek
This week I finally was able to obtain a copy of "Tools and How to Use Them" by Albert Jackson and David Day. This is a book that I first heard about via the Cool Tools blog started by Kevin Kelly. Unfortunately, as soon as the book was featured on a post in the blog, the prices for used copies shot up from just a few dollars to a few hundred dollars. I've been monitoring the prices for the last few months, and was finally able to get a UK version, which appears to be identical, except it's called "The Complete Book of Tools and How to Use Them". In addition to the concise explanations of the purpose and use of the tools, one of the things that I think makes the book really cool is the hand-drawn illustrations of all the tools. Here is a picture of 2 of the 12 pages on pliers:
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