Gen7 Z axis issue

So I was able to get Teacup loaded on my gen7 1.3 painlessly. Everything is working fine - except the Z-axis is not turning properly. It almost immediately smoked the Pololu driver.

I plugged in a new driver and it gets very hot as soon as any of the axis are turn on. The motor makes a bad humming sound like it's violently skipping steps, but doesn't rotate at all. Its not a wiring or mechanical issue - it's the same deal with or without the Z motors plugged in or another motor plugged into the Z jack, and I've double checked the traces and soldering and all seems well. I suspect the E driver may have the same issue as well, but I haven't plugged in a Pololu there yet. I've trimmed the Pololu pot up and down with no real results. Is this a firmware issue? What am I missing here?

Also, the config file says:

Set your microcontroller type in Makefile! atmega168/atmega328p/atmega644p/atmega1280

If you want to port this to a new chip, start off with arduino.h and see how you go.
*/
#ifndef __AVR_ATmega644P__
#ifndef __AVR_ATmega644__
#error GEN7 has a 644 or a 644P! set your cpu type in Makefile!
#endif
#endif


I have a 644 installed and I only see an option for 644P in the Makefile. What am I missing? Is this possibly causing my trouble?

I've also killed several pololus on my Z axis. In my case it was a "cold solder" point on one of the noice canceling capacitors.Every other axis worked just fine and also the Z did it's job for lets say half an hour so I didn't expect my soldering. You might also have a second look on it.

Hmm well coincidentally the only bad toner transfer part I had was on one of the caps on the Z axis. I had to tie the capacitor lead to the pololu header. It, unfortunately, isn't the issue. I've really checked and double checked every joint on the board now. Before I start ripping out and replacing components randomly, any other ideas?

Quote

I have a 644 installed and I only see an option for 644P in the Makefile.

644 and 644P differ in only three points:

- The 644P is slightly more energy efficient. 100 mW instead of 200 mW.

- The 644P has a second serial port, which is of no use for RepRap purposes.

- 644 and 644P have different signatures.

So, as soon as you could upload a firmware, you've solved all three of the above points.

A firmware issue is unlikey, because the firmware does not more than setting a constant voltage on the DIR and ENABLE pins and sending pulses to the STEP pin.

What you describe looks like an issue close to the motor connector. You can remove these (noise canceling) 0.1 uF caps and stepper drivers should still work. You can measure motor coil resistance with motors plugged in but Pololus removed to check traces and connectors. Also, none of the motor connector pins should have contact to anything else but their Pololu pin.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Thanks for the help guys. After a few nights of checking the motors, drivers, wiring, traces and soldering, I still don't see the problem.

UPDATE:
Hmm, I have two bad stepper drivers (not including the one I cooked already). Question now is what did to break them....

Edited 3 time(s). Last edit at 03/31/2012 10:46AM by largecamel.