Removing nut off ballscrew, I've never seen anything like it

[geohot]

The thing in red is what i am trying to get off. There are no set screws around it. I have tried spinning the shaft the opposite direction, it won't budge. Has anyone seeen anything like this before? If so, do you know how I could get it off?

[HuFlungDung]

Looks like a double nut, with a dog setscrew drilled halfway into each. Remove the setscrew(s) completely, then you should be able to loosen off the outer one.

[MrBean]

Looks to me like you'd need a "C" spanner. I think that's what it's called. It's basically a hinged C shaped (part ring) with a pin on one end that locates in one of the holes around the body of that nut.

Not sure if that's right, but that's how it looks from here.

Regards Terry.

[geohot]

How would I go about removing the set screws? They don't appear to have a head on them.

[Al_The_Man]

It looks to me that there is a threaded dowel, if so you need to use a bolt extractor that threads into the dowel and then draws itself out either by slide hammer or exerting force against the retainer.
Car steering wheels use this same idea.
Al.

[MrBean]

Ok. Maybe what Hu said sounds better.

[Geof]

Originally Posted by Al_The_Man It looks to me that there is a threaded dowel, if so you need to use a bolt extractor that threads into the dowel and then draws itself out either by slide hammer or exerting force against the retainer. Car steering wheels use this same idea. Al.

Al is correct but a little ambiguous; he says you need to use a bolt extractor which could be taken to mean you need one of those reverse thread tapered extractors for broken bolts. That is not the case all you need is a bolt or theaded rod the same thread as inside the pin. Threaded rod is better; you screw a length in, get a bushing slightly larger than the OD of the pin and slide this onto the threaded rod, then a washer and nut and tighten the nut to pull the pin up into the bushing.

I have copied one of your pictures and drawn a white arrow on it pointing at two semicircles which do not quite line up. This nut assembly is probably something to do with adjusting tension or backlash and you get different amounts of clearance by lining up different semicircle pairs and driving the pin in at that location.

[geohot]

Thanks for your help. I put in a screw, LOC-TITEd it, and unscrewed it. It came out perfectly. The front half of the nut unscrewed and then the back half slid off. After much effort, I got the ballscrew out.