MORI SEIKI SL80 - FS18iT

[crow36]

Dear all,

I'm currently having this problem with the SL80 turning machine.
The load for the Z-axis is inconsistent. When the problem arise,
the lead for the threading cycle will also be messed up.

I've tried moving the only the z axis and the load goes up n down on the load meter. When i shut the machine down n power it up again the problem sometimes goes away.

Already replaced the end bearings for Z-axis but the problem is still there.

Any idea whats the problem guys?

Thanks
crow

[JohnnyTurn]

If your lead on a machined thread is wrong. You may have a faulty spindle encoder. Your machine has Z axis load meter? The load meter on most machines is for the spindle only. Not for the Axis drives.

But if you do have a load meter that you are sure is for the Z axis load, it could indicate mis-alignment. Has the machine been crashed before? If not, you have a bad Z axis motor or Z axis drive. It will be one of these problems, I'm sure.

How about your spindle? Is it smooth and quiet with zero backlash?

Check these out,

JT

[crow36]

JT,

I dont think the spindle encoder is the culprit as this also happen when i move the z axis by jog mode only. i will try to swap the servo drive and then the motor to eliminate the problem. Btw what do you mean by misalignment?

Thanks for the info.

crow

[JohnnyTurn]

Crow,

What I mean is, If the machine has been crashed you could have a Ball screw problem. You could have the turret sadle twisted on the Z axis ways. You just might have a bad MPG wheel.

Does this only happen when you use the MPG wheel? When you run a program does the machine act normal? If it's not mechanical, it's Servo motor or Drive.

Good luck,

JT

[crow36]

Hi JT,

As i know, there is no accident being reported.
Also i'm using jog mode when moving the z axis, therefore MPG not related.
This morning when i powered up the machine and jog the z axis, the load went was inconsistent. Then when i shut off and power it up again, the problem went away.

Suspect the servo drive at the moment. Will try swapping it soon.
Thanks again

crow

[underthetire]

Things that can effect load

Ballscrew bearings not installed correctly or bad ( you can not simply change them out, you must set stretch of the screw and rotational run-out during assembly) . This is on 99% of mori machines

Ballscrew bent

Thrust block alignment

Power supply, drive unit problem.

Lubrication problem.

Keep in mind, when you power up a Mori, the lube pump runs right away. Make sure the pressure is in the green section of the gauge.

[crow36]

At the moment, i'm suspecting the drive unit or the power supply unit.

This is because every morning when we power it up, we can see the load fluctuating when moving the axis in jog mode.

All i do is to power it off n on again and the problem will disappear for the whole day. The problem only appear the next morning when we power it up.

Currently doing it every morning as i still waiting to swap the units.

Thanks for your info btw

crow