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Repstrap Al (75% done?)

Posted by mikefazz 
Repstrap Al (75% done?)
November 15, 2009 09:46PM
So its been a while since I last posted but I have made some progress in the last few months. I have all the structure in place along with the stepper motors and chain. Most the electronics are done too.

Some features that may help others:
- attaching the gears to the motors (from old bike de-railers) is accomplished by drilling out the metal bushings and tapping them for small pinion screws. A slot cut in the gear allows it to be pushed back over the bushing with the pinion screw in place. Some glue holds it in place well.
- tensioning the chain: While working on a way to do this a roommate suggested using guitar string tensioners which he had some old un-needed ones. They make adjustment simple

So my issue now is with actually controlling the steppers. When I run the stepper tester code they all work fine. When I load up the firmware and try to position anything it slightly jerks and the big chips get real hot so I don't leave it powered long. I have tried checking the wiring and the stepper to make sure the colors of the leads are correct. I don't have the end stops in place and I haven't made the stepper for the extruder yet (been avoiding the SMT one I gotwinking smiley). Oh and the com test works but the motor tester gives scrolling garbled text... and doesn't work.

Some future issues to work out:
- 80/20 bearings... yeah we'll see how they do
- Electronics enclosure... I added lots of fans hopefully that is OK

progress is goodcool smiley

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