Cross slide half nuts for 7x12

[Brian]

A continuation of the feed screw thread.

  The cross slide nut.pdf (Size: 324.73 KB / Downloads: 45)

Enjoy Brian

[EdK]

Brian,

Do you have any more details on that mod? It's not clear to me what you did. More pictures or a drawing would help with the details.

Thanks,
Ed

[Brian]

Will this help

   
Brian

[EdK]

Perfect! Thanks Brian.

Ed

[PixMan]

I had made a new split cross slide nut like that for "fullautomike" when he was rebuilding his Harrison M300 lathe, along with a mating screw. On my own Victor 1640, I had simply bought a new screw & nut set from the manufacturer. Both work in a similar fashion, though no pins to slide on. The one in my lathe has held position perfectly for years, zero backlash between the 5/8-5 ACME thread and the nuts. I don't know how Mike's is working because he seems to be an "unregistered" member here now.

The only problem I have with mine that I cannot seem to fix is the pair of nuts on the end of the screw which keep unscrewing themselves and giving me lots of backlash. They are fine pitch bearing nut style with a tabbed washer between them. The washer is definitely keeping the two nuts tight to each other, but they back off together. Any ideas on how I might fix it? I'm thinking my only alternative is to mash the threads between the outer nut and the end of the screw using a center punch. I'm open to any suggestions.

Here's what the nuts I'm referring to look like.

[EdK]

Ken,

Are there enough threads there to make and install a nylon lock nut of some sort?

Ed

[PixMan]

Not really Ed. Looking at it now I'm thinking the best thing to do would be to take the nuts off completely and add set screws that have brass tips to prevent mashing the threads. They would have to be tiny set screws because the nuts are thin. I would just make a single, wider nut with set screws, but the threads on the screw are metric and I don't have the 70T gear I need to make metric threads.

[DaveH]

One way (albeit a lot of work) is to drill and tap the outer nut and use a grub screw with a copper slug to tighten on the threads.
May be just use one nut instead of two.
Just a thought

DaveH

PS Ken You posted just before I did

[DaveH]

Ken,
It does show how great minds think a like

DaveH

[stevec]

How about one metric nut (if it's std. and available) and a nylon tipped setscrew?