Hmmm, tried this in a different forum with no response. I will try again here.
I have a Kelling (Automation Technologies) KL34-180-72 DC servo motor connected to a Gecko G320X drive. I am using the Kelling 72V, 20A power supply. I have it temporarily mounted to the knee on my Bridgeport to do some testing to see what ratio to gear the pulleys before I build the final mounts. Right now it is set up with a 2:1 ratio. I know that ratio is a bit low, but I want to see what I can drive with the motor then gear it a little more. With the smallest pulley I can get on the motor and still have enough meat on the hub to tighten the set screws I can get a 3:1 ratio and still have the lead screw pulley smaller than the dial so I can still use it easily in manual mode.
When I first tried this I connected the motor directly to the power supply without the Gecko. Moving the table up it moved slower than it did going down, but it still had plenty of torque to truck it right on up.
After connecting the Gecko and running it with Mach III to see what max speed I could get I expected that it would still have the same torque available and I would not have a problem until I exceeded that max speed going up, but I was very surprised that I could not get the table to go up at any speed. It moves down just fine, but going up it sometimes just does not move at all and sometimes it starts to move and goes just a little way then stops.
I have not done the PID tuning on the Gecko yet, but I did set the pots to the recommended positions and I have the max current cranked all the way up on the drive. I ran through some troubleshooting with Gecko on the phone and all the other settings seem to be fine. I have tried with the jog speed set very slow and faster all with the same results.
Any ideas what to check next? I have not put a meter on the motor direct to the power supply since I don't have a DC meter that will go over 20A, but it is a 20A power supply and the motor is not stalled so I am making the assumption that it is not the 20A limit on the Gecko that it keeping the motor from running. Is it normal to be able to get more torque out of the motor when connected direct to the power supply than when the Gecko is driving it?