Myford ml7 6″ 4 jaw chuck

[von dutchParticipant @vondutch]

[von dutchParticipant @vondutch]

Evening all,I need some advice on my 4 jaw chuck it's a slim body 6" burnerd one with a backing plate threaded to suit a myford lathe,whilst using it on my ml7 I noticed it does overhang the front of the lathe bed ways by about 1/4".Can I remove backing plate and is it possible to turn a press fit insert into back of chuck to suit myford spindle or could I remachine backplate to make it thinner.The chuck does clear the bed ways but if I wanted to machine anything larger diameter the jaws will foul.All advice greatly appreciated.

[Michael GilliganParticipant @michaelgilligan61133]

That’s unfortunate

The custom Myford version has a screwed body and no backplate … to overcome that problem.

MichaelG.

[von dutchParticipant @vondutch]

Yes I've seen those hence why I wondered if I could turn up a press fit insert to copy that idea,it's a decent quality chuck that I got for a good price

[Michael GilliganParticipant @michaelgilligan61133]

Posted by von dutch on 03/04/2021 20:49:04:

Yes I've seen those hence why I wondered if I could turn up a press fit insert to copy that idea,it's a decent quality chuck that I got for a good price

.

Sorry for not stating the obvious …

As Meg Ryan famously proclaimed : Yes, Yes, Yes !!

MichaelG.

[von dutchParticipant @vondutch]

Ha ha ,I was just wondering if anyone had made there own insert,if it's possible or maybe I can make the back plate a bit thinner?

[Michael GilliganParticipant @michaelgilligan61133]

If it was me [which it’s not, because I have two of the Myford ones] … I would make an insert, and fix it with Loctite 638.

Other opinions will probably be available, but no-one has come forward yet.

MichaelG.

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Edit: __ Have you see this thread : https://www.model-engineer.co.uk/forums/postings.asp?th=118763&p=2

Edited By Michael Gilligan on 03/04/2021 21:28:30

[Pete.Participant @pete-2]

Could you turn down the backplate and use that to press inside a suitably bored hole in the chuck, or is that what you'd planned?

[von dutchParticipant @vondutch]

Not sure yet which route to go,shame to turn away the faceplate,when I could make an insert or use another faceplate that doesn't have so much overhang?, putting out there I guess for ideas

[not done it yetParticipant @notdoneityet]

Question: How thin would the back plate finish, if you removed the minimum to clear the bed?

[von dutchParticipant @vondutch]

I will measure when home from work

[old martParticipant @oldmart]

The insert method would certainly work in theory, but absolute precision would be needed. You won't be able to just skim the front face as with a backplate. If the face does not run perfectly, everything in the chuck will also not be in line with the spindle axis. This is a disadvantage when using a four jaw chuck, you will not be able to turn work round in the chuck and have the ends in line.. Have a close look at the backplate, it may be possible to remove some of the rear so that it screws on a bit more, then face off the front and you will have more thickness removed. I would not thin the outside of the plate below 6mm thick.

[von dutchParticipant @vondutch]

I've had a brief look at backplate,it would be reduced to about 1/4" thickness for the jaws to clear the bed ways,I did wonder if an insert would have to be fitted very precisely,I might see if I can reduce the thickness of the backplate,do you think reducing it to 1/4" thickness is to much ?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by old mart on 04/04/2021 15:13:49:

The insert method would certainly work in theory, but absolute precision would be needed. You won't be able to just skim the front face as with a backplate. If the face does not run perfectly, […]

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As before

If it was me [which it’s not, because I have two of the Myford ones] …

What I had in mind was to make and assemble the insert with the register and thread unfinished: Then clamp it to a true-running stub mandrel [no, not Neil] by its own jaws and finish to size.

A lot of faffing about, but I think it should work nicely.

Alternatively … the chuck may look like Nick’s one from the other thread [von dutch hasn’t commented on that] in which case the preferred solution might be different.

MichaelG.

[old martParticipant @oldmart]

1/4" backplate thickness is plenty. If you have front mount with threads in the backplate, it would be a good idea to get some longer bolts that allow nuts and washers to be added at the rear. There is usually a step for the chuck register nearer the centre. The chuck should touch the outer part before the centre part if that is so. Some backplates are flat fronted and their od fits the register in the rear of the chuck.

[von dutchParticipant @vondutch]

Michael g ,I did look at that thread yes very helpful sorry I didn't comment i have been working nightshifts, making a rear tool.post , trying to fathom the chuck in-between , reading these posts and most importantly obviously keeping my girlfriend happy!.When I've finished the work in the chuck I think I shall take back plate off and have a look it looks very similar to the one in the link,also when I bought it I do remember thinking blimeys that's a thick backplate I reckon it must be at least 1/2".Thanks for your help people's.

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