spindle thread

[john brown 17Participant @johnbrown17]

[john brown 17Participant @johnbrown17]

Has any one come across a lathe with a 1 27/64" x 8tpi thread on the spindle its on a very old IXl lathe , l did think it was 1 3/8" but trying that size its to loose,be nice to have a new chuck for it when the old girl is restored.

john

[DC31kParticipant @dc31k]

Surely the chuck does not use the threads alone for location. Does it not have a register inboard of the threads? The register size and fit of the chuck to that register is way more important than loose or tight threads. The threads do not want to be too tight lest they try to influence the register.

[OldironParticipant @oldiron]

Is it IXl or Zyto branded? Try here for lots of info IX1-Zyto

regards

[colin hawesParticipant @colinhawes85982]

DC31k is correct; the thread will be 1 3/8 x 8 and it's job is to push the chuck onto the register which IS a close fit. Colin

[David George 1Participant @davidgeorge1]

Could it be 36mm x 3mm pitch as they were made in Germany in the main. Have a look at lathes.co.uk

David

[john brown 17Participant @johnbrown17]

Thanks for that lathe link ,it looks like l have got a 6" IXL AKT gap bed lathe ,but could not se on the site about the spindle thread size,yes do get the thread an register side buit 1 3/8 " is really loose .

john

[Pete RimmerParticipant @peterimmer30576]

I don't find it unusual at all. I had to make a backplate for a IXL dividing head last week which was 1-41/64" – 11tpi

[DC31kParticipant @dc31k]

Posted by colin hawes on 04/02/2021 16:47:44:

DC31k is correct; the thread will be 1 3/8 x 8

If you have understood my post as saying this, then I am sorry that I did not write more clearly.

A simple OD measurement of the register would give a more reliable indicator of the thread size than an OD measurement over the thread crests. If the register is 1 3/8", then it would be difficult for the thread to be 1 27/64" (27/64" is bigger than 3/8" so the register would not go over the male thread).

If the register is close to 1 27/64", then further investigation is needed, including David's metric possibility. One way may be to do a three wire measurement of the thread. There is a good online calculator somewhere for this, whose address has been posted here before. It will tell you the best size wires, but will also give you the measurement if you input the wires you are using. This means you can use three drill shanks, three drill blanks or three bits of silver steel or whatever you have to hand that is close.

On further reflection, I am wondering how a loose fit of a 1 3/8" (female?) thread leads to the supposition that the mating (male, spindle?) thread is 1 27/64", a bigger size. Surely the only way to get the two threads to mate at all is some gender reversal?

[john brown 17Participant @johnbrown17]

Many thanks for your help ,being honest it would have nice to get a back plate etc already made,and not keep hiding under the stairs when it comes to screw cutting ,but my mentor friend and his side kick have given me the push to do it , and l do have a chuck that fits the lathe ,so will make a dummy spindle and take good measurements from the spindle when its on the bench and go for it .

john

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