Haas VF3 Servo Over Current... after installing new motor.

[jeffserv]

Hello,

Haas VF3 Serial number 2014 1994 model... Have owned for a year without any trouble...

I have a problem, I got the Ground fault error, which by bypassing that discovered my Y axis motor had a short... to the brush housing... I rebuilt the motor, new bearings and seal, new brushes... put it back in... then I got the Y Cable Fault error message... looking in the book, looked like it wiped the encoder out when it shorted... to ground.

So after more than a week, and much frustration... I need to get this thing going... I order in a new motor, and new cable, and installed them... I got work to do...

No..... Y Axis Servo Overcurrent... The Y axis jumps a little, about .100 thousands and stops giving this error...

I no longer have the Ground fault error, I no longer have the cable error, and I have a brand new motor...

Can someone help me with the proceedure to set up the parameters for the new motor... I think it does not know where it is... so jumps and then gets the error...

Help...

- Jeff

[Al_The_Man]

Is it possible the encoder phasing is wrong?
If the encoder direction is opposite to the motor direction, it is possible that this fault may occur.
This can usually be cured by swapping the A & /A on a differential encoder.
Or a quick easier test is to swap the motor leads, as long as it does not have a tach, as this would lead to another test of motor/tach phasing.
Al.

[jeffserv]

Anwser: Yes

In the Haas Parameters for the Y axis, it is possible with software to reverse the Encoder signals, the motor direction, as well as the limit switch and so forth, so that if it is wired backwards, you can simply tell it to read it opposite or inverse.

I have played with these settings, to no avail... still jumps, then gets the error... no matter if set forward, or backwards?

Thanks -

[rlabonte18]

Have you tried swapping the amp with the x axis to see if the error follows the amp or you new motor? If the old motor was shorted to ground the amp maybe bad also. These amps are pretty inexpensive I think around 400 for the brush motor style. the new cable and motor should have been plug and play no params to change or anything. The only problem that you might encounter is a zero return margin too small which in that case would lead to a parameter change, but the axis would still move.

[jeffserv]

Ok, there may be the problem... I did swap the A axis board, with the Y, in my original effort to fix the Y axis, I have not swapped it back...

This could explain why the new motor is not working. As well, before, when I bypassed the Y cable fault, and turned of the cable check... then I got the same action out of the other motor... overcurrent. Makes since that the encoder or cable was bad, and that the original drive swap, should be put back, and possibly the A axis board is not the same as the x,y,and z...

I will switch them back, and see what happens... will get back to you.

Thanks, Jeff

[jeffserv]

Thanks, the original board switch was the problem. I am up and running.