I am stuck with Biesse Rover 322 retrofit

bevins wrote:

The setting has to do with the encoders I think.

It seems to me that I got the drives to work. Thank you for the hint that I did not have them enabled as the drive had to show "run" to be in operation mode, the manual took me there.

Now if I enable the drives, motors are slowl drifting and if I give voltage to analog input of the drives, I can jog the motors. So far I did that with sliders in pyvcp panel. Now I would like to connect pwmgen to PID modules. I would appreciate any hint for initial PID values. I suspect that drives work in velocity mode, so I would need FF1=1.
I have been playing now, but I am puzzled. I set P = 0.01, Deadband = 0.0005, FF1 = 1 and all the rest are 0.
The output value is too large, it moves the motor way too much and then jumps back. If I disable drives (independetly from LinuxCNC, which thinks all is fine, because ferror is set to huge value) then in HalShow I see that pwm value is set to 1,5, which would give 1,5V to drive, but the drive has max input 6V, so that sudden jump would be expected as the drive tries to move it at 1/4 of max speed.

I would suspect Output_scale and Max_output to be responsible, but nothing changes, if I set output_scale = 100 and max_output = 1 or if I swap the values to output_scale = 1 and max_output = 100. Why is there no change? Am I missing something very basic here? It has been 4 or 5 years since I dealt with servos...

Before doing any of that make sure your encoders are connected to mesa boards and working. This is important to have connected so your servos don't run away.

for your output:
OUTPUT_SCALE = 10
OUTPUT_MIN_LIMIT = -10
OUTPUT_MAX_LIMIT = 10

Something like that.

And don't forget about encoder scale

bevins wrote:

And don't forget about encoder scale

Yes, encoders are connected and are working. I have calculated the scale approximately, I have to do some tests to adjust it, that is for tomorrow.

I wopuld put FF1 back to 0 and the rest at 0. Start with upping the P. Mine for these drives with 1.8kw ac servos are around 15.

bevins wrote:

I wopuld put FF1 back to 0 and the rest at 0. Start with upping the P. Mine for these drives with 1.8kw ac servos are around 15.

Ok, thank you!

Tommy, thank you for the link!

I will try to do some tuning tomorrow morning, will report back then.

viesturs.lacis wrote:

bevins wrote:

I wopuld put FF1 back to 0 and the rest at 0. Start with upping the P. Mine for these drives with 1.8kw ac servos are around 15.

Ok, thank you!

Tommy, thank you for the link!

I will try to do some tuning tomorrow morning, will report back then.

What Servos you have on that machine?

bevins wrote:

What Servos you have on that machine?

Attached is a picture of a label on Y axis motor.

You mentioned that you changed servodrive settings related to encoder. Today I wanted to start by making sure that encoder feedback works correctly and to get the input scale as precise as possible. Currently it seems to be way wrong, measured and actual distance traveled differs approximately 10 times. Seemed like simple adjustment of scale value.
But what puzzles me is that Y axis is slowly drifting and it can travel 40-60 mm while there is no position change detected. So I wanted to check servo drive settings regarding position output. The manual I found seems good enough to explain, which parameter is that and how to get there, but what I do not understand is how to get in "setting mode". Manual and label on drive says to use SW4. But nothing happens to any of the drives, if I press SW4 shortly or press and hold it for longer time. Tried to hold it up to 10 seconds. Nothing. What am I missing here?

YAY! I got servo runaway on Y axis! I had never seen that before. Good news is that it seems that it did not break the machine. Well, I already had a conclusion that there is something wrong with encoder feedback from Y axis motor and I was trying to understand if that is encoder itself or cable to drive or is it the drive's position output that is wrong. Well, it seems that I have an answer now.
Where do I start tackling this one?