RE: [CAD_CAM_EDM_DRO] stepper update

Thought I'd give update on our travel a certain distance and stop car
project. We were trying to use steppers, but just couldn't get power we
needed from fax machine stepper. Monday night, we switched to a VEX motor
and shaft encoder, did some math to get appropriate encoder clicks, ran a
couple times, changed the speed we traveled and went to the competition on
Tues AM, without significant data from test runs. On T, ran 8.1 meters on
the same surface as the competition. Checked the unit into impound and
waited to run. Had to program for 6.3 meters and predict time the run would
take. They were about 10 cm offline (needed to work a bit more on aligning
wheels) and about 2 cm long, and missed the time by 0.17 seconds - among the
top 3 runs of the day!! They did outstanding work under pressure, for which
I'm very proud.

Now, however, I think it might be hard to get them to go back and try to
make the steppers actually work. I wanted to do this first, so we could
build a little 3 axis router for which we've rec'd many donations from this
group. We might just have to move to the router, as even if we get the
stepper to work, I doubt we'll do better than we've already done.

Thanks for your help, and I'll update again the next few weeks.

Chuck Merja
<http://www.srvscience.org> www.srvscience.org
www.3rivers.net/~chuckm/index.htm

Lemelson-MIT Inventeams - http://web.mit.edu/invent/n-main.html

US FIRST Robotics - http://www.usfirst.org/
lat/long 47.52383 -111.67912


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