PDA

View Full Version : What Causes a Ballscrew to Chirp??



CJL5585
02-01-2005, 11:24 PM
Ballscrew chirps ... Thought it might need some grease ... greased same ...still makes chirping sound .... Any ideas?

Appreciate any response.
Jerry :violin:

cncadmin
02-01-2005, 11:38 PM
maybe a metal chip is caught inside?

Pythagoras
02-02-2005, 12:04 AM
Well if you had a screw in your ball, you'd chirp too.

ESjaavik
02-02-2005, 12:07 PM
On some screws the seals are so effective that greasing the screw does not help much, it does not get into the nut. Did you use the grease port?

CJL5585
02-02-2005, 12:48 PM
The unit is factory sealed. It was designed for Class II cleanroom operation, and does not have a grease port. It does not make any sound if it is slow jogged or turned by hand. The chirp is not a major problem, as it can only be heard while operating a g-code program without performing any machining operations. I double/triple checked everything, and took the ballscrew mount loose in an effort to check the ball bearings running in the thread grooves to no avail. It is a quality piece of work.

Thanks guys- apparently it isn't a major problem.

Jerry :banana:

Al_The_Man
02-02-2005, 12:49 PM
Could be a chipped ball.
Al

gus
02-07-2005, 06:22 PM
Meebee it is actually the bearings

cadman
02-08-2005, 10:25 AM
The Z axis on one of my Fadals would chirp. Turned out to be the bearing in the ballscrew mount near the home position. Doesn't hurt the finish or any dimensions and the chirp hasn't gotten any louder so I just live with it.

CJL5585
02-08-2005, 12:54 PM
Found problem to be in motor mount.

Removed ballscrew from Y axis and allowed it to turn in bearings. Chirp was still there. That solved 2 possible problems. One, metal chip inside ballscrew, and Two, un-equal loading or stress related chirp.

Ran stepper at approximately 800 RPM and listened for chirp in (double) bearings. Chirp appeared to come from shaft coupling area and was amplified through the ballscrew shaft. Loosened motor mount screws with stepper turning shaft. When screws were loosened, chirp disappeared. Re-torqued mounting screws and unit operates normally.

Apparently motor mounts were not perfectly centered causing chirp.

Thanks a lot guys.
Jerry :banana:

KiwiOS
02-09-2005, 02:46 PM
If it only chirps when the axis initially accelerates or decelerates it could be the coupling between the drive motor and the ball screw. Ill fitting guards can also sound alot like what you describe. Does this only happen around one certain area in the machines' range of travel?. Does it only make noise with rapid (G00) movents?.

CJL5585
02-09-2005, 03:04 PM
The chirp only showed up at high feedrates. The problem was with the motor mount not holding the motor in perfect alignment.

Thanks for the tip.

I have now solved this problem.
Jerry