G0602 X-Axis Ball Screw

[Flenser]

Hi all,

I converted a Grizzly 10X22 lathe to CNC last year. I was in a hurry, though and took some short cuts. The one glaring issue I want to correct is that I initially mounted the X-Axis ball screw on top of the cross slide instead of under the saddle where the original lead screw was located. My problem then as now is the ball nut has a flange that's too big to fit in the channel.





These are super cheap ball screws I got off ebay from linearmotionbearings. They have so far been both accurate and durable. My only complaint is he only has flanged ball nuts available. What I'm considering is cutting the channel in the saddle to fit the ball nut, but I'm worried that will weaken the dovetails too much. Has anyone tried this?

Thanks,

Jeff

[SCzEngrgGroup]

If you really want to keep that screw and nut, why not re-machine the nut to remove the flange, and put a different end on it?

Or, machine a couple of "notches" in the saddle and use set-screws to attach the nut, and let the screw travel back and forth with the cross-slide?

Regards,
Ray L.

[ViperTX]

I believe the ballnut is attached to the cross-slide and you want it to travel down the channel of the saddle?

If so then as Ray said "machine the flanges of the ballnut to allow it to travel through the channel". Then you will need to machine a bracket to allow you to attach the ballnut to the cross-slide.

Paul

[Flenser]

Yes, the ballnut is attached to the cross-slide. I was hoping to avoid machining the ballnut, though. It has proven to be much harder than the ballscrews were. I will have to grind it, and probably get some grit inside the nut.

You two are probably right, though. Machining the ballnut is the better option. It's just that cutting the saddle would be so much easier...

Jeff

[TXFred]

I will have to grind it, and probably get some grit inside the nut.

I wouldn't consider grinding a ballnut without first unloading it. After all, you'll be getting metal dust everywhere, and also dipping the ballnut into water to cool it as you grind. Getting grit inside is not likely, it's certain.

But if you've unloaded it, then it's no problem. Just clean up the nut with a parts washer or brake cleaner once you're done, and put it back together.

[Flenser]

I was lead to believe reassembling a ball nut can be very... challenging. I've never tried it, though.

[SCzEngrgGroup]

I was lead to believe reassembling a ball nut can be very... challenging. I've never tried it, though.

It's really not a big deal at all, once you know how.

Regards,
Ray L.

[Flenser]

Well, getting it on and off the screw without losing the bearings was pretty simple, but I haven't been able to find much information on reinserting the bearings once they are free of the housing.

I have a "spare" empty housing now, because I was playing with g-code commands right after getting everything hooked up - everything but the limit switches, that is. The bearings were scattered, but the ones I found could be inserted by unscrewing the nut just enough to leave a bearing sized gap. Is that essentially what I would need to do??

Thanks,

Jeff

[SCzEngrgGroup]

Well, getting it on and off the screw without losing the bearings was pretty simple, but I haven't been able to find much information on reinserting the bearings once they are free of the housing.

I have a "spare" empty housing now, because I was playing with g-code commands right after getting everything hooked up - everything but the limit switches, that is. The bearings were scattered, but the ones I found could be inserted by unscrewing the nut just enough to leave a bearing sized gap. Is that essentially what I would need to do??

Thanks,

Jeff

There is generally a removable ball return guide, that allows the balls to be slipped back in, with the nut on the screw, then the return guide is replaced.

Regards,
Ray L.

[Flenser]

Hm, there are only plastic inserts with no obvious way to remove them from the outside. If there is a return guide, I sure don't see it. These are the same as the ones I have. Maybe they are cheaper than I thought...

Jeff

[SCzEngrgGroup]

Hm, there are only plastic inserts with no obvious way to remove them from the outside. If there is a return guide, I sure don't see it. These are the same as the ones I have. Maybe they are cheaper than I thought...

Jeff

I have not taken apart that style, but those plastic plugs must be the returns. I would guess they just pry out, to expose the ball tracks.

Regards,
Ray L.

[Flenser]

I found a thread with a few different people reassembling these specific ballnuts. It's probably not quite as simple as machining the saddle, but maybe not beyond my limited skills

I also cut one flange from the spare housing using a diamond dremel wheel mounted in the the mill. With max speed of 1500 RPM I was only able to cut 0.003" at a time without the wheel chattering, but at that depth I could feed as fast as I could turn the handle. I was surprised it cut so well after having dulled a HSS end mill and chipped a carbide insert with little more than a few scratches to show for my effort.

Thanks everyone for the help. The g0602's saddle thanks you as well!

Jeff