Ball Screw Newbie Question

[Ferrari2007]

Hi All,

I have what is most likely a dumb question, but here goes....

Building a CNC router and when I installed the ball nut for the Y axis and rotated it along the ballscrew, several of the ball bearings fallout the front (flange side) of the ball nut. Is this normal or will my mating flange provide the means to keep the ball bearing in?

When I did the same setup for the X axis I have not encountered the problem, it rotates fine and does not lose any bearings. Was I just lucky on the X axis or do I have a problem with the Y axis nut?

Both ball screws are identical as well as the ball nuts.

Thanks

[Ferrari2007]

Posting a picture of my setup.

Once again I am sure I am overlooking the obvious, but appreciate any input.
THanks

[Glacern]

The balls should not have fallen out of the nut. Sounds like something may have gone wrong during the installation, and some of the balls slipped past the return tube.

What kind of a ballnut are you using? External circulation with a bolt-on return tube, or internal circulation?

If you need a place to upload photos, you can try our free photo upload: http://www.glacern.net

-Sol
Glacern Machine Tools

[Ferrari2007]

Sol,

Thank you for your response and use of the upload site.

I am using a Thompson 1" round ball nut with external return tubes. Picture link is below

http://www.glacern.net/free_photo_upload/P1010005.JPG

Is there a seal that keeps these in that could have been damaged during installation? These are brand new and as I did on the X axis, I slid the ball nut on the screw while removing the cardboard tube as it threaded on...seemed pretty mistake proof, but it sounds like something went wrong like you said.

Thanks again

Kevin

[Glacern]

Hey Kevin,

There is no seal, just the cardboard tube, which may have slipped during installation.

Rebuilding the nut should be fairly straightforward, albeit a bit tedious, especially since you have two ball circuits. There's a step-by-step on how to rebuild these types of nuts somewhere on the web. I don't have the URL anymore, but perhaps someone else here does.

-Sol

[Ferrari2007]

Hi Sol,

I will search around for the rebuilding article on these and see if I can't get them reloaded properly. Its good to know that nothing is damaged, just sounds like I may have started off wrong during the installation.

Thanks again for the help.

Kevin