Mitsubishi spindle problem

[wcopley]

Has anyone had or know of a solution to this problem?

Mitsubihi 520m Control, Mits Drives, Mits Spindle motor,

when machining inconel 625 .075 doc 70 rpm 4. ipm 20 horse spindle motor no gear box when the inserts break down the spindle will only go to about 60% then the motor stalls and the table continues to move no Alarms etc. Just broken inserts when doing this manually in jog mode if you reverse the axis movement the spindle will turn again.

We checked param and everything seems good from what we have wrote in
Thanks in advance
Bill

[MetLHead]

Hi Bill,

Did this problem just recently start? Has the spindle seemed wimpy before? Does the spindle load stay at 60% when the motor stalls?

Can you tell if the motor is a dual winding motor? If so, do the contactors switch state when changing speed ranges?

This does sound like it could be a parameter problem, do you have the model numbers of the drive and motor?

Thanks,
Scott

[wcopley]

This problem is recent since this is the first time we ran this slow and are cutting inconel. in steel at 450 rpm and .125 doc 14 ipm spindle rearely went over 20%. there are no speed ranges. I can get motor and drive model numbers tommorow at work and post then. What concerns me the most is it does not alarm out when it does this and it causes quite a mess broken inserts etc. and it is real boring standing there staring a the spindle for 10 hours a day. 60hrs apiece only 14 more to go
Bill

[MetLHead]

Unfortunately, the control does not automatically detect that the spindle has stalled and stop the feed. This would need to be added to the PLC logic and may not be a simple thing to do depending on the complexity of the PLC program.

The lack of power may just be that you are running the motor too slow. For these motors, power is proportional to speed from zero up to the base RPM of the motor. Base RPM may be as high as 1500 depending on the motor model. In a case like this, a gear box is a good thing.

Scott

[wcopley]

Darn that is not what I wanted to here. This has been a good machine so far we aquired it used it is a 1998 Sintec Tiawan made and have had no trouble up to now It has out done our brand new Milltroncs VM30XP thru spindle coolant and all the fancies its been down almost as much as it has ran and its only 16 months old

[wcopley]

I think it is still a Param problem. I have been machining for over 30 yrs, CNC since 1979 and could always run 100% on the spindle.
Bill

[MDLang]

Not a mazak but with a mitsubishi drive and spindle servo the overload sensing should be done by the IPM (Inteligent power modual) that is the busness end of the drive unit. Any alarm state should be triggered by the drive regardless of parameter settings. To have the spindle resume rotation after the load is removed makes me think the IPM in the drive is failing.

Could be wrong.

Mike

[Al_The_Man]

Originally Posted by wcopley I think it is still a Param problem. I have been machining for over 30 yrs, l

To prove the parameter theory, just re-load the parameters from floppy.
Al.

[wcopley]

Originally Posted by Al_The_Man To prove the parameter theory, just re-load the parameters from floppy. Al.

Al
The only parameters we have on floppy are the ones I copied out of the control after we recieved it.
Thanks
Bill

[wcopley]

Originally Posted by MetLHead Hi Bill, Did this problem just recently start? Has the spindle seemed wimpy before? Does the spindle load stay at 60% when the motor stalls? Can you tell if the motor is a dual winding motor? If so, do the contactors switch state when changing speed ranges? This does sound like it could be a parameter problem, do you have the model numbers of the drive and motor? Thanks, Scott

Scott

Here is the spindle drive model MDS-B-SP-260
AC Spimdle motor model SJ (that is what I think th sj is) Hard to read the way they mount the tag in behind the spindle.
Thanks
Bill

[Al_The_Man]

Originally Posted by wcopley Al The only parameters we have on floppy are the ones I copied out of the control after we recieved it. l

That would probabally be the ones to reload.
Al.

[MetLHead]

Originally Posted by wcopley Scott Here is the spindle drive model MDS-B-SP-260 AC Spimdle motor model SJ (that is what I think th sj is) Hard to read the way they mount the tag in behind the spindle. Thanks Bill

Bill,

Can you get the rest of the motor number? Should be something like SJ-15A or SJ-18.5A

Also, if you can post the current parameter settings that would help too.

Thanks,
Scott