Submitted by cronix on Thu, 05/12/2011 - 21:05
Posted in
Wow, I am almost there. I hope to have a working dolly very soon from now (within 6 weeks). This will be a prototype dolly because I want to test the mechanics and electronics first. I have chosen to make the dolly based on a stepper motor and the OpenMoco engine.
My most important parts:
Motor:
http://www.damencnc.com/damencnc.php?dir=cpt&time=1305233867&langId=EN&idComp=208
My very beefy stepper driver:
http://www.damencnc.com/damencnc.php?dir=cpt&time=1305233550&langId=EN&idComp=200
Gearbox:
http://www.ondrives.com/gearboxes-reducers-wormwheel-gearbox-pf20nm-nema-17.html
Arduino and electronics are housed in:
http://www.watterott.com/index.php?page=product&info=1663
But now my bug report. I want to use the kill signal of the engine. That way I can save a lot of energy from my batteries. The problem is that the engine is turning on the stepper driver just before it is sending steps to the stepper driver. The time between the on signal and the first step is very, very short. My driver doesn't have the time to wake up before the firs step command is sent. I am therefore missing steps. I can very easily reproduce this when I use:
motor 0 steps 1
The motor doesn't move at all when I use the kill on command. It is working fine without.
Maybe we should add a short configurable delay just before the first step is given?
Sounds exactly like the
Sounds exactly like the driver responds more slowly than the ones I tested with. No biggie, will include a configurable delay in the next update =) (Which is coming soon, I hope!)
!c