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VQC 20/50A M2 drive faults

mada87

Aluminum
Joined
Dec 27, 2017
Hi all,

I am getting intermittent faults on both Y or Z axis (mostly Y right now. Most are a sevro lag excess fault, machine runs fine otherwise. When I had this happen on another machine it was because the timing belt had a bad spot and was slipping. This belt seems to be in really good condition, anyone have any ideas on what else to check?

Thanks!
 
servo lag means axis did not move the same as commanded
so
could be hurt drive (but that tends to be "axis drive alarm")
could be burnt motor
could be jammed up
could be bad code causing interference with something like end of screw, piece party or the like
on a mill and some bigger lathes it could also be failing counter balance over working drive
 
On some controls there is a sw adjustment to allow more time for the lag to resolve. However will the effect the overall actual amount the axis moves?
If you can locate the value in the sw, note it, place a very accurate indicator on the axis and compare values before and after changing the value. Just a rough off the top of my head idea, a starting point.

Best of luck, D
 
On some controls there is a sw adjustment to allow more time for the lag to resolve. However will the effect the overall actual amount the axis moves?
If you can locate the value in the sw, note it, place a very accurate indicator on the axis and compare values before and after changing the value. Just a rough off the top of my head idea, a starting point.

Best of luck, D

I was wondering if there might be some sort of adjust meant. what does sw stand for? Is it a parameter or an adjustment on the drive?

I have swapped a new drive (keep the top card of the drive though at Mits suggestion), seems to be faulting less but still faults, I always have thought that the Y axis seemed a little jerky. So I looked up info on drive adjustments and tried adjusting drive settings (dials that you adjust on the drive top card), I may have made it better but not much (I certainly can adjust them to make it worse). Lastly I have a third shift although I rarely am around then but it does seem to fault more often on third. Makes me wonder if the voltage is running higher or lower during the night and causing more faults.

Thanks
 
I would do a reality check of your lube system to insure there is lots of lube on the ways.
If the ways run dry, it takes more power to position (larger lag) all axis can be affected, and motion can be jerky as the breakaway friction has increased.

Since you have been tweaking adjustments, and then find dry ways, problems may increase when you get the lube system working properly.
This is because things are way overcompensated now and need to be put back to normal.

Bill
 
I would do a reality check of your lube system to insure there is lots of lube on the ways.
If the ways run dry, it takes more power to position (larger lag) all axis can be affected, and motion can be jerky as the breakaway friction has increased.

Since you have been tweaking adjustments, and then find dry ways, problems may increase when you get the lube system working properly.
This is because things are way overcompensated now and need to be put back to normal.

Bill

Good idea, don't know why I didn't think of it. I did take pictures of the drives settings so that I can put them back.

After continuing to trouble shoot I have found a few things. There does seem to be one spot or area that it seems to fault in more often. It also seems to fault more often during the middle of the night (on third shift). I have never been able to watch the drive when it faults but when I watch it otherwise the current draw always appears quite low on the readout. If the machine is stopped and you feel the timing belt on the z axis there is no movement, but when on feel the timing belt on the y axis (the one with the problem) there is a hum/vibration.
 
most of the ways were oiled but one face seems dry, so I oiled it all by hand and it didn't seem to make a difference.

Something else that I have found now is that it is much more common for it to fault when moving under load (cutting) in the Y minus direction, I have the same cut elsewhere on the part except the machine is moving in Y plus and it rarely faults during that cut. ( It still does fault at other random locations but probably faults in this certain area when cutting in Y minus 5 or 6 times before some other random location.)
 








 
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