Bidirectional Problem with UHU Board

[jlobin]

I am currently trying to use a UHU Servo Controller 3.0 with the original PCB, not the HP version. The motor runs fine, and can be tuned well, in one direction. When I reverse the motor direction, steps cause the motor to respond in large amplitude, short cycles. With no steps, the motor will hold position, but it only seems to respond correctly in one direction. I've tried different motor/encoder combinations, and I've switched out all the ICs. None of that helps. Has anyone seen this? Any ideas on what is causing this?

Thanks,

[mibo1112]

Hi there,

It looks to me like a something I had problem with, though didn't try to rotate motor connection wires. I'm using Mach3Turn software.
When I jogged in one direction, motor was turning. When I jogged in the other direction (by pressing the other direction tastature arrow) motor didn't turned at all. When tried to turn it by hand, it couldn't be done, motor holded position.
I checked defined numbers for Step/Dir pins (in Config-Ports and Pins) several times and nothing.
But, while checking one time I saw that for "step" pin was selected digit 2, and for "dir" pin digit 3. That was for X axis. But, it should be digit 3 for a "step" pin and digit 2 for a "dir" pin.
So, while I was checking earlier, I just was making attention on the digits itself and not the position.
So, check that again and check it carefully. Maybe that is a problem,

Milos.

[LZ1TWB]

Originally Posted by jlobin With no steps, the motor will hold position, but it only seems to respond correctly in one direction.

Does the motor hold its position correctly when stopped and you try to turn it with a hand? If not, you could search for some interconnection between traces. I've had a similar problem, when one of the traces that passes between 2 legs of an IC had made contact. Of course this was due to the homemade PCB. Commercial PCB's should not have this problem. What kind of motor/supply voltages do you use?

Todor