Myford Lever Operated Collet Chuck

guess

Mike,

I think it is infact a Burnerd chuck flogged by Myford.

In my Burnerd collet chuck on my Colchester Master 2500, there is a ring of bronze where you have the two slippers. The ring occupies the entire slot that your slippers run in, the outer edges are chamfered to give clearance for the operating ring that has the lever attached.

AWEM

Andrew

Thanks for the reply.

What I don't understand is how a solid bronze ring can be fitted into the slot. Is it split in some way?

Mike

chuck?

shape.

chuck

slipper

attached.

Andrew

Thanks for the reply.

What I don't understand is how a solid bronze ring can be fitted into the slot. Is it split in some way?

Mike

Not noticably! I assumed that the body of the chuck unscrewed, parting the two sides of the slot.

AWEM

The "Myford ML7 Lathe Manual" by Ian Bradley gives a section drawing of the lever operated collet chuck. But I think it is of an earlier design as it shows a shoulder rather than a slot and the "thrust ring" is retained by a "thrust ring & pin assy" is retained by a circlip" - terms in quotes are the terms used on the drawing. However a close up photo show no signs of a circlip! and fit your description - hence my belief that that the drawing is of an older model. I imagine that a solid ring could be made of bronze undersize on the bore, oversized on the o/d. Split diametrically into two hale rings, soft soldered back together, finished to required size then desoldered giving to halves that when clamped firmly together by the "pivot pins" would give a good running fit with considerably more wearing surface than the two bits of fibre shown in your photos.

Brian

rote:

he lever operated

a slot and the

are the terms

tion - hence my

, oversized on

to required size

e a good running

Thanks for that.

I did have in mind something along the lines you suggest, but I wanted to check first that I hadn't missed something!

The next challenge will be to obtain a suitable piece of 3 inch diameter, 1/2 inch thick, phospor bronze!

Mike

lever operated

slot and the

- hence my

required size

good running

I'd hold on before you do. I can't see any point in having a continuous ring for what it's doing, rather the current blocks or phosphor bronze versions should be fine. Having used similar collet closers before the pads are only loaded when you opening or closing the collet I believe and may only rub lightly when the lathe is running. Shame the picture here is not clearer (bottom of page)

I agree with David's comment. I have one of these collet chucks and it has two slippers just like the ones you have in reddish fibre like material and they work fine. They are only under load when you open or close the chuck. My chuck does look a bit different to yours, maybe it's a later or earlier design. However, the bronze/brass frame looks the same. In my chuck the slippers just push a ring which forces steel balls into the body of the chuck, which in turn force the collet holder forward towards the tailstock, closing the collet against the large threaded collet retainer. As far as I know the fibre slippers are original and they are still working without problem. They don't look worn but if they were I wouldn't replace them with brass or bronze.

Mike

occupies

chamfered

drawing of the lever operated

rather than a slot and the

in quotes are the terms

description - hence my

the bore, oversized on

finished to required size

would give a good running

continuous

bronze

believe

picture

Well that illustration certainly doesn't have the big bronze ring that mine has - maybe they were just slippers originally?

AWEM

Someone with one of this type of chuck has told me that their chuck

b1_photos/

Before you rush to give yourself a lot of work,you might consider sticking with the Tufnol or similar slippers. I used to run automatic multispindle lathes.The collet closers on these were Tufnol and there was only one slipper.Typical duty would be opening and closing an 8" diameter bobbin six times a minute while it was turning at 1200 rpm.It would do this ten hours a day at least five days a week.That Tufnol slipper would last at least two years.Brass/ bronze wouldn`t have lasted a month in that application. Mark.

Thanks to all who replied.

I have now re-examined my chuck very carefully, and there is no sign of any way of separating the slot. There is certainly no circlip and removable section. It is not like the drawing in the Myford Series 7 book mentioned above. However, I notice that the photo in the book alongside the drawing is unlike the drawing! In fact it looks more like my chuck, with no circlip on the end, no visible bronze bearing ring, and no lubrication nipple on the attachment spigots. One of my concerns about the tufnol slipper pad arrangement was that the location of the outer assembly was poor, but if the link to the headstock is rigid, as shown in the photo, this would be taken care of. Other chuck versions with the continuous bronze ring bearing seem to have a loose double-jointed link from chuck to headstock. My chuck came with the link to the headstock missing, so no further clue from that!

So I think I will make some new tufnol pads, and a rigid attachment link, and see how well it it all works.

Thanks again

Mike