[dneisler]

I was working on a customers part just now, and some bad gcode ran my y screw off the nut just enough 5 of the balls came out. Is there a way to get them back in there? I need help badly.

[cjdavis618]

This should clear it up for you.

http://www.youtube.com/watch?v=cPOhA...eature=related

[dneisler]

Well, my nut looks nothing like that. I don't have any of those tubes. If I do, they are internal and I cannot get to them.

Here is a pic of the nuts I have. They only a small plastick section that could be the tube but I cannot get it to come out.

[cjdavis618]

I see. Sorry, I don't have those nuts on mine.

I would check with the company that made it or get in touch with CNCfusions. Maybe they have some ideas.

I ended up running my ballnut off twice before I decided to weld a washer to the end of the shaft. That has stopped ball loss for me.

[devers6]

I have the CNCFusion deluxe kit as well, so I know what you're talking about. I was worried about overtravel on the Y so I installed a hard stop to prevent it; but it's a bit late for that now...

I have had the opportunity to reload balls in a few ballnuts, one a dual-circuit nut that was fairly similar to the CNCFusion. Here is how I did it: I got some white lithium grease and swabbed it all around the circuits inside the nut, so that the balls would stick in the track without having the holding tube in place. You can then work them into place in the holes they use to circulate. I lost all the balls, so I had them all to reload; but with careful attention I got my ballscrew back. You have to be very careful when screwing the nut back onto the ballscrew - a finger inside while rotating it on will help keep the balls in place. I was given advice that if you encounter even the slightest resistance, back off - otherwise you risk jamming the balls somewhere that might make it impossible to go either forward or backward; which would be a hell of a fix.

Like I say, it was a different ballnut; but I suspect the approach is valid. Lithium grease is very sticky, maybe too much. I've heard Vaseline will work without being quite so messy.

[devers6]

A bit off-topic on this thread, but a little horror story that illustrates that you can come back from a real disaster:

One day I received a ballscrew I had bought on Ebay. It came packed in a long cardboard tube that the guy had stuck wood blocks in the end and then stapled the hell out of them with a pneumatic stapler. I spent about half an hour trying to dig them out with a screwdriver and pliers; finally I gave up and took the tube over to my band saw and sawed off one end. Bet you can see this coming - when the end came off, it was filled with that spray-foam insulation and embedded in the cutoff end was a nice slice of the plastic end cap of the ballnut, exposing about a dozen balls and a bunch of intricate tracks for them to recirculate.

After cussing up a storm and doing my best to kick myself in the butt, I sat down and surveyed the damage. The endcap was a total loss - sliced in half with no hope of being glued back together. But fortunately, it looked like the other side of the ballnut had the exact same end cap. So I removed it, cleaned it up nice, made a silicone mold and cast a copy of it in urethane. The new part came out an exact replica; I was able to reload the balls and install it in place of the sawed-off one and I had salvaged my ballscrew.

Just goes to show that although ballscrews are one of the scariest things in the shop when they come apart, they will go back together. After all, someone had to put them together in the first place. Best thing I learned in dealing with ballscrews - work over a towel. If any balls drop out, they will be cought by the towel. Otherwise, they will bounce right off the bench and roll incredibly far away.

[dneisler]

Thanks everyone. I played with it now for about 4-5 hours total and I finally got it back. I did talk back and forth with CNC Fusion, which was great help. About 10 balls came out of mine total, and I lost one. CNC Fusion told me I would be fine one short. Lets home so. I now have it back together and moving very nicely. I put the seals back on each end and it now a little harder to turn, but still very nice. So I am hoping for the best so I can get back to my RPM sensor in a aluminum case that I am almost complete and my X3 belt conversion that I am just now drawing up. Didn't want to waste time on things like this, but sometimes you just have to...

Again, thanks to everyone who helped and responded.

[The Blight]

I can still find balls from a little disaster I had a while ago. There really is no friction in linear rails and ball screw assemblies.

After you have put all the balls into the nut (with lithium grease or vaseline), just put the tube back in (assembly tube) and put the nut back on the screw as you would with a new nut. You don't have to mess around with it with your finger inside the nut.

[cadmonkey]

...X3 belt conversion that I am just now drawing up...

Love to see this one when you've got something to show

I'm still finishing up my X3 CNC conversion and am eager to expand the power, durability, sound, controllability, etc.