You can use the hex shafts from AM if those dimensions work for you, or you can machine your own. A very inexpensive ($50-$100) tool that makes this extremely easy is a hex collet holder such as
this. Put your stock in a lathe collet of the correct bore and clamp the collet into this holder. The holder can be clamped into the vice on a manual mill. Then run down one side of the stock with the end mill, rotate the collet holder in the vice, and repeat until you have six identical sides.
You can also buy hex rod from various metal suppliers, but I am unaware of specifics there.
Another thing you'll want to think about is the pieces that go on the shaft. Many you can get with a hex bore, but if you ever need to do it yourself, you will need a hex broach, or a sponsoring machine shop with one, since they are significantly more expensive (~$800 for rotary).
Many students I have met will insist that nothing is better than FIRST robotics. And most people would agree that a ham sandwich is better than nothing. So does it logically follow that a ham sandwich is better than FIRST robotics? - tsaksa [more] 
05-09-2011, 18:02
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