Myford ML7 Chucks – Which one?

[ZanParticipant @zan]

If you get a new Chuck go for a 4 jaw self cantering. They give a very solid grip on material are incredibly accurate and contrary to popular belief they still grip hex material on centre. Despite the warnings above, my 125 mm has been on my well used S7 for 20 years with no ill effects

[DiogenesIIParticipant @diogenesii]

GandM Tools have a tidy used 100mm TOS with both sets jaws etc. already on a Myford backplate listed at the moment – I have one, it's a solid and dependable chuck..

Edited By DiogenesII on 11/11/2020 06:32:23

[Ramon WilsonParticipant @ramonwilson3]

Doc G, I have two independent chucks a 4" and a 6" the latter with Myford internal fitting so use those for irregular shapes.

As said I bought the SC 4 jaw thinking it would be handy not to have to clock square stuff in when using those – ust pop it in the chuck and get going. I use it for round most of the time now but of course it does square and hexagon when required. No, it does not work independently – another SC chuck but more versatile. Recommended!

Ramon

PS If you go this route you could fit your existing 3 jaw with soft jaws and have more versatility – something else I use constantly throughout a build – very useful.

Edited By Ramon Wilson on 11/11/2020 08:23:41

[Dr_GMJNParticipant @dr_gmjn]

Thanks all.

[Dr_GMJNParticipant @dr_gmjn]

Just noticed Arc do a Self-branded 100mm s/c 4 jaw chuck “Chinese Origin”. Anyone got experience of them? At least it looks nicely finished.

[peak4Participant @peak4]

Posted by Dr_GMJN on 11/11/2020 21:37:31:

Just noticed Arc do a Self-branded 100mm s/c 4 jaw chuck “Chinese Origin”. Anyone got experience of them? At least it looks nicely finished.

I have an HBM one which seems nicely finished and is pretty accurate; currently mounted on my dividing head.
I'm sure Ketan would give you an honest opinion on the ones he's selling, particularly as he is changing supplier by the looks of it.

I seem to recall him writing about it in past thread somewhere.

Bill

[Mike PooleParticipant @mikepoole82104]

The number of broken teeth on ML7 back gears would suggest that they are fragile and it’s not a good idea to lock the spindle with this method. Usually a chuck will unscrew with not too much force required and the back gear will be untroubled but if a heavy interrupted cut has be used the chuck can be difficult to remove. Spinning the chuck on with enthusiasm can make it very tight. If the chuck is anything other than easy to remove then think again about how to lock or hold the spindle. Sparey was a very skilled engineer and most likely had a well developed sense of mechanical sympathy so wouldn’t employ a bigger hammer or longer lever if his chuck was stuck.

Mike

[egaParticipant @ega]

Posted by Zan on 10/11/2020 23:19:48:

If you get a new Chuck go for a 4 jaw self cantering. They give a very solid grip on material are incredibly accurate and contrary to popular belief they still grip hex material on centre. Despite the warnings above, my 125 mm has been on my well used S7 for 20 years with no ill effects

Interesting suggestion and I didn't know about the hex point.

I can't help feeling that a 4J SC would have to have exceptional accuracy for each jaw to bear equally on round stock. I have got one which I use for non-critical holding of cold-rolled square bar but for accuracy and grip would use the independent 4J.

[Howard LewisParticipant @howardlewis46836]

For my admittedly larger chucks on my larger lathe, a hole was drilled into the chuck body. Into this is inserted a bar with a short matching piece of Silver Steel attached to it. With the belt tight, a swift blow on the end of the bar with a copper / hide mallet slackens the chuck.

To avoid risking the gear teeth, you could grip a piece of relatively large hexagon bar in the 3 jaw, ( Square for the 4 Jaw ) and apply a long spanner to the metal before using a copper / hide mallet on the outer end. The inertia of the motor and the Headstock usually provides enough resistance to a sudden blow, to slacken the chuck ..

If at first you don't succeed, give it another whack, and do follow through!

Remember the advice, not to run the chuck on under power. They will be quite tight enough, possibly more so, if just spun on by hand!

To reduce risk of chucks sticking, the threads and register on the Mandrel and in the chuck should be clean. Mine given a wipe, or brush, every time before fitting, (Ditto when changing from Internal to External chuck jaws. )

HTH

Howard

[Dr_GMJNParticipant @dr_gmjn]

I might have given the wrong impression somewhere, but I’ve never had an issue with the unscrewing a chuck. I’m doing light work, and certainly don’t over-tighten them. If I thought I was going to have to apply a hammer to the spanner, or extend its handle, there’s no way I’d be using the gears to lock it. Remember the gears themselves aren’t made of cheese – they can handle some torque…I’d expect way more than I ever apply on chuck removal.

[Howard LewisParticipant @howardlewis46836]

A friend with a Myford used to loosen the chuck with backgear engaged. I cut several replacement gears for him.

Glad when he sold the lathe.

A suddenly applied force has double the effect of a gradually applied one. So using a mallet on a spanner against the inertia of the machine, rather than locking the gears, does no real harm. It will slacken many a "stuck" chuck without doing damage. All that may happen is that the Mandrel may rotate slightly.

The "Mallet on a 12 inch lever on an unrestrained Mandrel" works on my 8" chuck (At least four times the inertia of a four inch chuck  ) so should have no problem with a four inch one!

Chucks do self tighten. As the work heats up, the chuck body eventually warms and expands and cutting forces screw the chuck a little further on. When cold the chuck contracts onto the mandrel, and will be tight to remove.

Howard

Edited By Howard Lewis on 12/11/2020 17:30:48

[Dr_GMJNParticipant @dr_gmjn]

Posted by Howard Lewis on 12/11/2020 17:30:23:

A friend with a Myford used to loosen the chuck with backgear engaged. I cut several replacement gears for him.

Glad when he sold the lathe.

A suddenly applied force has double the effect of a gradually applied one. So using a mallet on a spanner against the inertia of the machine, rather than locking the gears, does no real harm. It will slacken many a "stuck" chuck without doing damage. All that may happen is that the Mandrel may rotate slightly.

The "Mallet on a 12 inch lever on an unrestrained Mandrel" works on my 8" chuck (At least four times the inertia of a four inch chuck ) so should have no problem with a four inch one!

Chucks do self tighten. As the work heats up, the chuck body eventually warms and expands and cutting forces screw the chuck a little further on. When cold the chuck contracts onto the mandrel, and will be tight to remove.

Howard

Edited By Howard Lewis on 12/11/2020 17:30:48

Howard, I'd expect a shock load applied to a chuck (via. a spanner on the jaws or an in-situ hexagon bar or whatever) might not damage the gears, but might not do the chuck any good?

As I said I'm not doing heavy work where I'm generating significant heat or load. I've never needed anything other than hand pressure on a large adjustable spanner to loosen them.

[Howard LewisParticipant @howardlewis46836]

Doc, you are fortunate.

Most of the rest of us do find such problems from time to time. Hence the variety of solutions quoted.

The problem of sticking chucks will be present at some time for almost anyone with a screw on chuck.

may your good luck continue.

Howard

[Martin KyteParticipant @martinkyte99762]

Posted by Michael Gilligan on 10/11/2020 21:53:58:

Posted by Dr_GMJN on 10/11/2020 20:36:41:

Here's the quote from the Myford website:

THIS 125mm CHUCK IS TOO HEAVY TO MOUNT ON ANY MYFORD WITHOUT THE M42.5 x 2mm 4MT SPINDLE

.

Aaah … Fond memories

It’s almost exactly five years since we looked at that ^^^
**LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=111162

MichaelG.

Can I point out that the chuck in question was a 4 JAW self centring chuck backplate mouted. I have one and it gets used for accasional use. Myford (Mytholmroyd) did warn against it as well as selling it. I asked them at a show what the thinking was and the response was it just looks too heavy for the lathe. The went on to add that they would not imagine any harm being done by occasional use. My interpretation was that the notice was a recommendation but came accross as a warniing notice instead.

4 jaw independent chucks of this diameter don't overhang nearly as much as this chuck and the same is true of screwed bodied chucks.

I appologise to anyone who has been through this conversation before but I thought it worth including this in this thread too.

regards Martin

[Dr_GMJNParticipant @dr_gmjn]

Posted by Martin Kyte on 12/11/2020 20:35:43:

Posted by Michael Gilligan on 10/11/2020 21:53:58:

Posted by Dr_GMJN on 10/11/2020 20:36:41:

Here's the quote from the Myford website:

THIS 125mm CHUCK IS TOO HEAVY TO MOUNT ON ANY MYFORD WITHOUT THE M42.5 x 2mm 4MT SPINDLE

.

Aaah … Fond memories

It’s almost exactly five years since we looked at that ^^^
**LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=111162

MichaelG.

Can I point out that the chuck in question was a 4 JAW self centring chuck backplate mouted. I have one and it gets used for accasional use. Myford (Mytholmroyd) did warn against it as well as selling it. I asked them at a show what the thinking was and the response was it just looks too heavy for the lathe. The went on to add that they would not imagine any harm being done by occasional use. My interpretation was that the notice was a recommendation but came accross as a warniing notice instead.

4 jaw independent chucks of this diameter don't overhang nearly as much as this chuck and the same is true of screwed bodied chucks.

I appologise to anyone who has been through this conversation before but I thought it worth including this in this thread too.

regards Martin

Martin, the chuck in question that I’m talking about is a 3 jaw. It’s here:

**LINK**

[SteviegtrParticipant @steviegtr]

If you can get hold of a used 100mm griptru 3 jaw it has a very accurate adjustability. I got one on the myford ,when purchased along with a 125mm 4 jaw independent. I say used because it looks like they are around £500 new.

Mine was running out nearly 9 thou & i just thought it was how a 3 jaw was. Until i saw a thread on here about them being adjustable. This is how accurate i got mine at the moment. Other makes i cannot comment on as this is all i have.

Steve.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Martin Kyte on 12/11/2020 20:35:43:

Posted by Michael Gilligan on 10/11/2020 21:53:58:

Posted by Dr_GMJN on 10/11/2020 20:36:41:

 

Here's the quote from the Myford website:

THIS 125mm CHUCK IS TOO HEAVY TO MOUNT ON ANY MYFORD WITHOUT THE M42.5 x 2mm 4MT SPINDLE

.

Aaah … Fond memories

It’s almost exactly five years since we looked at that ^^^
**LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=111162

MichaelG.

 

 

Can I point out that the chuck in question was a 4 JAW self centring chuck backplate mouted. […]

 

.

Well yes, you can, Martin

… But may I then point out that my comment referred to the quoted text [in bold red] rather than a specific item of hardware ?

The same warning note is used in more than one product description.

MichaelG.

.

Edit: I’m not sure if this will work as a link … but it should go directly to my 2015 post where you and I discussed the advice you had received from Myford: http://th=111162&p=1901283

Oops … no it didn’t work as a link … but it’s on page 3

Edited By Michael Gilligan on 12/11/2020 23:46:22

Edited By Michael Gilligan on 13/11/2020 00:01:44

[Peter SpinkParticipant @peterspink21088]

Was lucky to find this a couple of years ago – brand new and unused for £100.

A 125mm Pratt Burnerd self centring 4 jaw which I've been using on my S7 with no problems at all.

It's a 'nice to have but not essential' bit of kit but I wouldn't be without it now.

Only slight drawback is the chuck and backplate are quite heavy to manhandle but those with bigger lathes are probably quite used to that!

[SteviegtrParticipant @steviegtr]

My mates Colchester student has a 4 jaw independant & self centering. It has 2 sets of key holes for the chuck key. Only problem it is around 9" dia & i would never lift it.

Steve.

[Martin KyteParticipant @martinkyte99762]

Posted by Michael Gilligan on 12/11/2020 23:34:01:

Posted by Martin Kyte on 12/11/2020 20:35:43:

Posted by Michael Gilligan on 10/11/2020 21:53:58:

Posted by Dr_GMJN on 10/11/2020 20:36:41:

Here's the quote from the Myford website:

THIS 125mm CHUCK IS TOO HEAVY TO MOUNT ON ANY MYFORD WITHOUT THE M42.5 x 2mm 4MT SPINDLE

.

Aaah … Fond memories

It’s almost exactly five years since we looked at that ^^^
**LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=111162

MichaelG.

Can I point out that the chuck in question was a 4 JAW self centring chuck backplate mouted. […]

.

Well yes, you can, Martin

… But may I then point out that my comment referred to the quoted text [in bold red] rather than a specific item of hardware ?

The same warning note is used in more than one product description.

MichaelG.

.

Edit: I’m not sure if this will work as a link … but it should go directly to my 2015 post where you and I discussed the advice you had received from Myford: **LINK**

Oops … no it didn’t work as a link … but it’s on page 3

Edited By Michael Gilligan on 12/11/2020 23:46:22

Edited By Michael Gilligan on 13/11/2020 00:01:44

Fair comment Michael. I know you are well aware of the history. I think Myfords are being a little over cautious and the warning seems to have been extended to other 125 chucks. My take is they are fine for occasional use but too big for a main chuck. The 4 Jaw independent screwed bodied chuck being the exception with it's small overhang.

regards Martin

[Howard LewisParticipant @howardlewis46836]

Has anyone suggested boring through the damaged jaw screw, making up a replacement end, and welding the two together?

It is even possible that removing the damaged screw, and squeezing together the fractured faces, possibly slightly veeing, and then MIG welding. Probably the pressure will need to be maintained while a couple of tack welds are made, before the whole crack is welded.Then filing back the weld, as little as possible, to ensure clearance may restore use.

The dings on the face, whilst signs of carelessness (to be charitable ) may not render the chuck useless.

Howard

[Dr_GMJNParticipant @dr_gmjn]

Posted by Howard Lewis on 14/11/2020 15:33:22:

Has anyone suggested boring through the damaged jaw screw, making up a replacement end, and welding the two together?

It is even possible that removing the damaged screw, and squeezing together the fractured faces, possibly slightly veeing, and then MIG welding. Probably the pressure will need to be maintained while a couple of tack welds are made, before the whole crack is welded.Then filing back the weld, as little as possible, to ensure clearance may restore use.

The dings on the face, whilst signs of carelessness (to be charitable ) may not render the chuck useless.

Howard

Howard, the split screw doesn't affect the chuck – just looks bad. I can still tighten it up fine.

[Howard LewisParticipant @howardlewis46836]

You are in business then! Even if it looks unsightly.

Probably driving on the bottom part of the square. Pity that someone, in the past, has brutalised the chuck so much.

It was a good chuck, but even so, it may still function satisfactorily, despite its appearance..

The reason for warnings about fitting big chucks is the concern that the weight of the chuck will so great as to cause premature wear of the plain white metal bearings in the Headstock.

Keep us posted!

Howard

[Dr_GMJNParticipant @dr_gmjn]

I've been waiting to get one of these, which I thought looked OK, and are recently back in stock:

3 Jaw Self Centring Cast Iron Lathe Chucks – Arc Euro Trade

But after measuring my original, the Arc one is considerably longer in terms of overhang, plus it needs a backplate which will add even more.

I'd rather have something much closer to the bearing. What do I search for, is it called a "low profile" chuck? Are they even available any more for the ML7?

Thanks.

[SteviegtrParticipant @steviegtr]

There are many lathes that benefit from being shallow in design. It is not just the Myford that benefits from this. Many small lathes do. There is even a guy on youtube who turns a deeper model in to a shallow one. A lot of work though.

Being available. I think most chucks are available if you search for one. New or 2nd hand is a question. Without getting your hands on a 2nd hand one & trying it will be difficult. Beware , some of the imported ones are not as good as they look. Just saying. I guess companies like arc etc will give you at least very good back up if you are not happy with the product. Have you actually rang arc etc to speak to someone who knows the answers to your long standing questions.

Steve.

[Author]

Posts