Fadal VMC4020A axis problem

[cwww]

Recently error #18 (motor overload) often pops up on the monitor when I jogged the y-axis (sometimes it happens when the machine is running), after resetting the axis driver it went back to normal again, but this error keep coming back...

I think the problem could either be a motor or an amplifier problem, but how can I check where the problem came from? or is there any ways to diagnose this problem? Please help... Thanks a lot...

[HuFlungDung]

Hi Cwww,

The first thing I would try to do, would be to disconnect the motor from the screw, and try turning the screw by hand (or with a small wrench, thus getting a "feel" for how the axis is. You may detect a bad bearing, or a gib screw that has come loose, and allowed the gib to wedge into the ways. This has happened to me

It is best to eliminate the possibility of a mechanical overload, before you start replacing motors, etc.

[cwww]

Thanks HuFlungDung...

But I'm still not very sure what I should do, the screw that you mentioned, is it item 26,27,31 and 32 (by refering to the 4020A parts manual page 4)? And which part is the gib and where are the ways? Can you please illustrate more (by refering to the parts manual) for me? Sorry I'm still quite new to the mechanical part of the machine... Thanks in advance...

Just in case you don't have the manual on hand, you can find it here:
http://www.fadal.com/ie/manuals/manuals1.asp

[cwww]

The Y-axis seems to be pretty ok except that it cannot moved with a high speed/feed, I've tried to jog it back and forth, it didn't give me any problem until I jogged it with a very high speed (following errors read more than 1500). It then choked a little bit and showed error #18 (sometimes "motor overload" and sometimes "servo amplifier fault"). Any advice for that?

[HuFlungDung]

Cwww,

I don't know much about your machine, as I do not have one of those. I would suggest that you talk to the factory technicians.

Is it possible that someone has been altering the setup parameters?

Perhaps you could get into the axis parameter setup, and decrease the acceleration/deceleration a little bit? Lower the Rapid rate a little bit? Or, perhaps the current limit is set too low on that axis for some reason. Compare values with the X axis setup.

[fjd]

I had this problem once turned out to be bad break switch.

[hardmill]

Pull off the way covers and make sure its not loaded up
with chips. I've seen simular errors on other machines
and the problem was that simple. We had gone through
all the things that you are checking.

PEACE

[cwww]

Originally posted by HuFlungDung Cwww, I don't know much about your machine, as I do not have one of those. I would suggest that you talk to the factory technicians. Is it possible that someone has been altering the setup parameters? Perhaps you could get into the axis parameter setup, and decrease the acceleration/deceleration a little bit? Lower the Rapid rate a little bit? Or, perhaps the current limit is set too low on that axis for some reason. Compare values with the X axis setup.

The problem is that the local distributor here doesn't have any qualified Fadal machine technician.

I don't think it's related to the setup parameters because I never altered anything there, and all the while I'm using the same settings...

Anyway, thanks...

[cwww]

Originally posted by fjd I had this problem once turned out to be bad break switch.

You mean the circuit breaker, or the fuse? Sorry I'm confused...

Originally posted by hardmill Pull off the way covers and make sure its not loaded up with chips. I've seen simular errors on other machines and the problem was that simple. We had gone through all the things that you are checking. PEACE

Thanks for the suggestion.
I've already cleared up the chips under the way covers, but didn't help much... still the same problem...

I've changed the y-axis amp with another one, but same problem occurred, so the problem is not on the amp. Maybe I should swap the y-axis motor with the another one to see whether the problem's still there or not...

[motomitch1]

That happen to me with the Z and it was 2 of the 6 brushs was bad i put 6 new ones in it and it runs good now.Fadal VMC4020

[cwww]

Thanks everyone for those valuable suggestions...

I've swapped the y-axis motor with another one, so far no error happen... but, the y-axis (with a different motor) is out of position (about .10" or .20"), when I coldstart the machine, the home position alignment marks didn't match each other, but can go to the normal extreme positions at +10.0000 and -10.0000 (it's a 40 X20 machine).

Then, I reset the home position of y-axis so that its home position alignment marks match each other, but now the extreme positions read +10.1740 and -9.8260...

Is there any simple ways to solve this problem? This is the first time I encounter this kind of problem, I'm not sure what I should do for this one...

[motomitch1]

yes thats easy to fix

1. cold start vmc
2.take cover off axis motor
3.losen the 3 screws securing the resolver and rotate the resolver
4.you will notice that rotating the reslover causes the axis to move a little.
5.contiune rotating the resolver untill the lines are aligned.
6.then tighten the 3 screws back up. put the cover back on , that should fix it.