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Need Help with mazak servo lag excess error

Unionbrass

Plastic
Joined
Jul 14, 2006
Location
eagan minnesota
I have an error on the x axis servo.
I have tryed swaping a cnc board 720
I have tryed swaping ball screw encoders.
I have tryed swaping motor encoders.
I have tested as much wireing as possible.
I have replaced the compleat 3 axis drive unit.
I have changed parameters

But I still have a servo lag excess error. The machine is running but if I bump the rapid travel up over 30% then the machine will error out randomly over the next few minutes. The time it takes to error out is proportional to the rapid percentage. I have had the xaxis counter ballance tweeked in and fixed.

The mazak repair man refuses to come back and look at it. I have had him in several times for this problem. I Have gone through numerous checks with mits on the phone for several houres at a time.

I am leaning twards the ball screw is binding or some sort of physical problem is causing the ball screw to move harder than it is suppoze to.

Anyone have any thoughts?
I am sick of running this thing at 30 percent and the boss is getting upsett that I have not fixed it in several months.

The servo drive flips several codes for about .5 of a second and then resets itself. It gets a red hard stop error. but then if you hit reset on the control and then hit start the machine will then start again from the begining of the part, whith the red error still on the screen. The repair man said that this is just not possbible. I have also replaced the battery backup and reset the parameters from the factory specks.
 
what control?
what machine?
will it do it on differant programs?
does it take longer on monday morning to alarm?
is this a legaly imported mazak or is it a bootleg hyundai?
 
The control is a T32-3
The machine is a SQT 10 MS
Same result different programs. bump up the rapid and it errors out.

No same monday as any other day.

The machine is ammerican as far as I know, and I have gotten the mazak repair man out hear many times, he just got frustrated and gave up after he extended all options. Basicly the mazak man said call mits, and the mits man said call mazak. I tryed to learn as much as I could and eleminated many possibilities of the problem by myself.

I am thinking that the problem is the ball screw, or the way covers.

But unfortunatly, I dont know how to dissasemble the x axis ball screw on the 45 degree and not have it crash and put it back together without running the risk of screwing something up. And if I did take it appart how are you to tell if it is damaged somewhere. The machine seems to only error in the x direction of travel, or if it is doing a x,z move at the same time.

I can manage to take the covers of and clean and inspect them, although I have not done this yet.
 
the fact that your never getting to the point of a drive alarm would imply that it's not bound mech.
if you were putting undo strain on drive over and over eventually it would burn the drive.
that coupled with the abitlity to run with a fatal red alarm(servo lag on MY mazaks can only be cleared by powering down machine).
would lead me to think you got some kind of bug in the NC
not my specialty
or maybe the cableing between drives and NC
we need a control expert to step up
anybody?
i might pull that lower x cover and run a dry cycle for awile to see if that changed anything
would eliminate at least one thing
 
Ok I will try taking the x cover off and see if it works. Yes the error has baffled people at mits over the phone and the mazak repair man who has been hear just scratches his head. yesterday the dumb machine blew a temp overload switch on the hydrolic motor, and I tracked it down and reset it, man I am sick of this dumb machine.
 
I have had a similiar problem a few years ago on a QT-28 lathe where we had to replace the bearings and the ball screw. Since you have switched out cards and encoders, I would lean more towards a mechanical problem. A servo lag excess is usually caused by a increased resistance on that axis.
I would first look at your load meter and see if it is higher than normal. If it is high then I would say your bearings or ball screw needs replaced. Also, listen and see if the x-axis is noisy. This could be an indicator that a bearing is going out. Also, it could be an alignment problem with you x-axis. If the machine has been crashed the ball screw could have moved and not be perfectly in alignment.
 
I figured it out it was the hydrolic counter ballance that was busted on the inside. Every now and then the nut would plug the hole for the hydrolic fluid and cause the servo lag error.
 
thanks for coming back
alot of this stuff just drifts off into space
and we never find out what it was
real answers help the old data base
 








 
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