I solved "most" of my ground loop problems and now have a new one.
My motor is disconnected from its load and will freespin in open air for testing.
I have 1 servo motor using the X axis. (encoder is on back of motor)
Starting from Machzero X, no matter what distance I tell the servo to travel, the camsoft interface X axis readout ends up at 25.xxxx . If I tell the machine !FEEDRATE 10:MACHGO 10 the servo motor will make rotations to 25.xxx
If I tell the machine !FEEDRATE 10:MACHGO 2 the servo motor will make rotations to 25.xxxx
Now I realize that the setup gear ratio and encoder counts per inch need to be entered correctly but that should have nothing to do with the camsoft interface X axis readout right?
If I tell camsoft to go to x=10 then the readout should say X=10 when it finishes its move right? (regardless of the actual move made).
So why does it seem to be going to the same point every time?? I am also getting an error "Begin with motor off?" after each move. I am assuming that this is caused by massive position error.
The encoder counts I am getting seem smooth now. When the motor is under torque, the encoder readout is very stable +/- 1 count.
Also, with the control wiring disconnected from the drive, the drive sits stable under torque. As soon as I connect the +/- 10v signal wires, the motor oscillates. (ground loop?).. So I disconnected the ground wire from the +/- 10v reference signal from the ICM2900 and the problem went away. Is this normal to have it hooked up with only 1 wire like this? I did a google search for Ground Loops and read about certain conditions when only 1 wire is desired. Any thoughts on this?
And why does this thing always want to go to 25 ??? Something strange here..
Thanks,
Murphy  |