Myford Lever Operated Collet Chuck

Does anyone in the group have a Myford lever operated collet chuck?
I ask because I'm renovating an old chuck, and I need some help
understanding the design..
In my rather battered example, the hinged bronze frame which the lever
operates retains two slipper blocks, which in turn run in a 1/2 inch
wide groove in the rotating part of the chuck. On my example the two
slipper blocks are made from some dark red fibre material, and are
very worn. Wear aside, they look wrong (and home-made) to me, not
least because of the material used, and because they provide no
lateral location. I would have expected them to be made from a
material such as phosphor bronze, and to be more circular in shape.
Someone with one of this type of chuck has told me that their chuck
has a solid circular bronze bearing ring, rather than the 2 slipper
blocks. However, I can't see how this could fit my chuck, so I guess
there may be was more than one version.
I have placed 3 photos of my chuck and the "slipper blocks" in
Photobucket. See
formatting link

Any help much appreciated.
Mike
Reply to
mikecb1
Loading thread data ...
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
Reply to
Andrew Mawson
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
Reply to
mikecb1
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
Reply to
Andrew Mawson
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
Reply to
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
Reply to
mikecb1
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)
formatting link
. Have you tried asking Myford.
Reply to
David Billington
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
Reply to
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
Reply to
Andrew Mawson
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.
Reply to
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
Reply to
mikecb1

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