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Deckel FP4A Part tool marks

Harri89

Cast Iron
Joined
Nov 21, 2016
I am getting x and y both sides tool marks from the Cutter. This is mostly beacaus of the slow control and Cutter standing still?

Or backlash in the ballscrews/thrust bearing?

X axis has some backlash somewhere. I cannot use 0.01mm increment button to move the axis. It will give an error and shutdown the control. Everythin else works like should.

More and more wanting to upgrade to Advantech LNC control. This one is so jerky with moves. Atleast with high feeds :D
 
I did yesterday the servo tune with OFFSET and TACHO. Before that i cleaned every tachometer. I was getting "error 17" From the Y-axis from time to time. Now in mode 4 i can jog every axis 0.01mm increment, but when i change X-Axis direction, i get "error 16". Y and Z no problem when dircetion changed.

I need to check the X-axis ballscrew thrust bearing.

I hope the servo tune fixed the error from the y axis, really annoying when it shuts down the machine in middle of a program...
 
have an electrical engineer look at the servo drive signals, the +/-10V ones, with a 2 channel scope, one probe at the motion control output, the other one at the input to the servo drive, write a program that moves the axis back and forth the same amount, like +/-100mm at decent speed and look for differences in the waveform on the scope

I'm suggesting this because of similar issues with my Mikron WF41, I was getting random drift up to 0.04mm most often on Z, less often on Y, it seemed to be more frequent when the machine was just switched on cold, and the control would error out sometimes, the issue turned out to be some additional relays added by someone before I got the machine, they were there to cut the signal from the control to the drives and switch to some outside source, the cables to the outside source were cut near the relays, but relays stayed in the cabinet, and oxidation on the relay contact caused my issues, I noticed differences using a scope just as previously described, removed all the unnecessary relays, rewired the signals back the way they were supposed to be and the issues immediately went away
 
Check your "X" axis for lost motion on direction reversal....
Take the cover off the "X" axis servo motor to expose the tacho commutator.
Setup a good indicator (.01mm or better) that is fixed to the machine vertical box ways (magnet base) and indicates to something mounted to the table.
Make a move in each direction (.01mm or more) you should see the commutator move for the tach, the indicator should record the move in each direction and repeat.
If the tach moves but the table (indicator) does not follow you have an issue with the thrust bearing, the ball screw or the anchor bearings at each end of the screw,,,,,

You can easily verify that the issue is not in the servo drive cards, by swapping the cards from the "X" with the "Y"in the Bosch drive.
Don't think this is where your issue lies as you have already been successful "tuning" the cards...betting its mechanical....

Cheers Ross
 








 
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