Need Help!- Noisy drive axis

[KTECH]

Hi every body. I have a 2000 3016L that has a very noisy x axis. Sounds like chewbacka from star wars! So far I have tried tuning the x axis amp. That did no good. Then I tried switching the x and y amp boards. That still didn't change anything. Also, I did NOT have any noise from it till I changed to the new style couplers when I put new thrust bearings in the bottom end. The guild ways look fantastic too. Has any one else had this problem??? I talked to a fadal tech and didn't have any luck there so I figured I would try this.

[Al_The_Man]

Did you try disconnecting the motor mechanically and run it?
This should pin it down to either Drive/motor Mechanics!
Al.

[KTECH]

If you mean unhooking the motor from the axis I did that when I put new bearings in. It was all very smooth. Its as if its getting feed back electrically. Like its fighting its self. The fadal tech said that all that vibration would wreak the new bellows style coupler if I didn't fix it. I have a feeling it has something to do with the drive motor its self. Does any one know how to finish diagnosing the problem with out spending 2 k on a drive motor just to prove whats wrong? i guess I could swap the z motor with the x to see what happens. Will this work? The y axis motor would be hard to get at.

[scadvice]

Swapping sounds like a plan. That way you can check both the axis mtrs and mech.
Steve

[KTECH]

Ok get this.... I put silicon on the bellow coupler and its quiet as can be now??? is this an issue with this style coupler? I never had the problem till I switched. Has anyone heard of this? It was so loud I was scared to run over 20 inches a min without it sounding like it was going to destroy something. Tomorrow I will try running a part to see what the finish looks like.


Thanks for the replies guys!

[Al_The_Man]

If you replaced the bearings in the motor itself and it is either BLDC or AC it is possible you disturbed the commutation angle if the feedback device was moved, this will give you the symptoms you describe.
Al.

[KTECH]

No I did not mess with the motor its self. I followed the instructions from fadal for tuning and balancing the amps. Thats the only other thing I did. The fadal tech was the one that suggested that to fix the problem. Im sure putting the silicon was just a patch for some thing truly wrong but if it gets me by for now Ill live with it. Ill do some playing tomorrow to see how well it cuts. I want to get another mill soon so I can investigate further later. Any ideas I still welcome though. Is it possible to put a scope on it to see the out puts and such. Is it possible that its a tach or encoder problem?

[KTECH]

Problem solved. The thrust bearing had some thing wrong with it. I put another new one in and it works great now. I when I jogged the table back and forth I could feel that the vibrating was coming from the lead screw side of the coupler so thats what drove me to take another look at it.

[scadvice]

Very common problem with Fadals with some miles on them...very easy fix also... one of the reasons I like the good old Fadals...
Steve