Anyone had luck building the Chopper board on Phils site??
I built mine, all parts as listed no substitution. It works but two problems,
1. The Fet outputs get super hot (even with a heatsink).
2. There is a jitter from the motors when I run them. The jitter occurs on all three of the outputs.
Before that (over a year) I was using resistors and everything worked great. But I wanted to improve performance with a 32V 10 amp supply. That would require some large rsistors so I decided to build the Chopper. Using the 3 axis board from Phils site to run the machine, the Chopper board is an add on for it designed by Mr. Tachus42 who designed the 3 axis board as well I believe. The steppers are 24v at 2 amps.
I have checked everything over and over. Using the 32V supply. I tried varying timing capacitors, recalculated the resistors, stared at the schematics, triple checked my board and solder connections, and searched the forum for hours. The voltages look correct and the wave forms have a nice chop (in my opinion anyway). Have there been any updates that maybe haven't been recorded somewhere. In my searching I have found several people that ran into the same problem.
Should I throw in the towel and maybe someone can suggest a better option? I hate to just give up as I have invested so much time.
Last edited by camcam; 06-26-2008 at 10:15 AM.
Had some time to do more testing (experimenting). If I leave everything on the board as if it were running on 30 volts, but use 12 volts for the power supply everything works fine. The FET stays cool and the jitter is gone!
I wonder if this circuit will work with 32 volts???