Quick release collet chuck clevis

Hi,
I recently bought a myford quick release collet chuck for my barely used (complete novice) Myford Super 7. It came with an earlier ML7 attachment which does not fit. Does anyone know where I can by the clevis and bolt, or a similar alternative, which goes through the headstock housing?

Many thanks in advance.

Tim

Hi Tim I havn't seen the collet chuck for your lathe before but I would have thought you would be able to turn something that fitts. It won't need to be a very close fit and should be made from mild steel or silver steel. Have a go you will learn by your mistakes and a if it dosn't fit change design and make again.

David

+1

Without casting nasturtions on the O/P, it's a common sign of the times "Where do I buy" sindrome. It seems that the old method of MAKING parts to make parts is dying due to the miss conception that time is of the utmost importance. Another thread running at this time is expounding the virtues of repair. Wouldn't advocate trying to make a wheel bearing for a car, but a bolt and a bit of slotted square bar??????

Regards Ian.

From Tim's wording it could possibly be he is not aware of the shape of the part needed and is looking for some help in designing the required part, perhaps the method has changed in many ways from the 7 to super 7.

That said I have to agree with the other posters re making the part.

Emgee

Is this the lever action quick change collet chuck that is being talked of? If so then the part is very simple to make, some square bar and a screw or two.I don't know if the fixing is different on the Super 7, but for the ML7 it is a simple 20 minute job, even for a beginner

Andrew.

Sorry, should have read the post more carefully, apparently the ML7 adapter doesn't fit. I would simply drill and tap the head stock and make it fit!

Andrew.

When I got a Myford quick release collet chuck for my S7 Mk1 it also came missing the clevis, it's a simple thing to make assuming you have access to a milling machine, if not you could even hacksaw the clevis cutout, no particular accuracy is required, it only works for a few seconds to open or close the collet, the rest of the time it just sits there, for the clevis pin itself I just drop a m6 bolt through the hole.

I've got to go out now but if you want I'll try and put up a photo of it later and list some sizes, but I've no idea what you have exactly with the ML7 attachment so no guarantees that what I have would fit yours.

John

Hi there,

Are we discussing this?:

Item #19 goes through the lugs on item #8 and through the eye on item #18. On early ML7s, the clevis bolt, item #18, screwed into the tapped hole in the clamp bracket, item #22,:

There's another picture of this clamp bracket in one of my albums.

The clamp bracket attached to the head-stock casting as shown here:

The clamp bracket attachment to the head-stock was a bit naff but I guess with care it could be made to work. Later on, Myford modified the head-stock casting to include a tapped hole to take the clevis bolt. (I'm afraid I can't find a picture of that. ) I believe the same tapped hole was/is used to support the chuck guard but it's either/or, not both.

Somewhere, I have a dimensioned drawing of the clevis bolt but I can't find it just now - I'll keep looking.

My apologies if I haven't used the same names for the parts as thos given in the items list!

Best regards,

Swarf, Mostly!

Edited By Swarf, Mostly! on 05/05/2021 13:42:45

The one I made for my S7 is very much like this one in the link, 3rd photo down with it screwed in the headstock.

https://www.model-engineer.co.uk/forums/postings.asp?th=129074

John

Hi there, again, all,

Both the 'pictorial view' and the air-brush drawing in my earlier post contain errors! The end of the operating lever must be allowed to move relative to the mandrel axis as the lever is operated. There should be a link between item #8 and the clevis bolt. It was/is a short length of flat-bar with a hole in each end.

Best regards,

Swarf, Mostly!

Okay, firstly thank you to everyone who replied. I'll take on board all the suggestions. I appreciate it's probably a very easy part to engineer in principle. I don't have access to a milling machine, however I do have a vertical slide. So, correct me if I'm wrong, I should be able to hold a bar of silver steel in the vertical slide, using a milling attachment in the lathe chuck, and mill a recess to form a u-shape or clevis. Then I can drill a hole for the bolt. Apologies, I was suffering from a lack of confidence mainly due to inexperience. I realise this is prohibitive to learning.

Sandgrounder, thank you for posting the link to the pictures of the attachment. It's very helpful to see how it was installed. I was concerned about the tension and the leverage required for the chuck to operate effectively.

Swarf, mostly, thanks for posting the schematic and other images. Incidentally, mine came with the attaching bracket visible in the second picture (brown background with allen key). I'll have a close look to see if I could engineer it to fit somehow.

In summary, I will hit the drawing board and post the results and conclusions. Once again thank you for everyone's input. I'm slightly overwhelmed by the number of people willing to contribute . Legends!!

Many thanks,
Tim

Edited By Lathe-argic on 06/05/2021 21:59:40

Edited By Lathe-argic on 06/05/2021 21:59:56

Edited By Lathe-argic on 06/05/2021 22:00:34

Edited By Lathe-argic on 06/05/2021 22:01:01

https://www.mcmaster.com/eyebolts/flat-shoulder-rod-end-bolts-5/

They are also available without the shoulder and also as blanks that are not threaded or drilled.

There's no need to use silver steel at all, you're just making things difficult for yourself, mild steel is perfecrly satisfactory.

John

And to ease your pain even further Tim, Drill a hole in the bar for the bottom of the slot, saw out the bit from the end and then subsequent milling operation is merely a "skimming" clean up. Might seem long winded but saves the cutter.

Regards Ian.

John, I certainly don't want to make things difficult so mild steel it is.

Ian, that makes the process seem very straight forward (famous last words) even for a simpleton like me.

Many thanks

Hello

I hope this is of some use:

Sorry for the crude sketch, its got all the info I think you should need! Like I said on the drawing the holes may be smaller depending on your generation of chuck as shown bellow there appears to have been at least 2 iterations of it!

Mine appears to have been welded at some point, although I think its just threaded now as I detailed above

Shows the 2 different versions

William

Back in the 70's and 80's when I worked at a small firm, we had an ML7 and a Super 7 and the collet system like the thicker one in William's photo fitted both lathes with no bothers. It was much quicker for production jobs.

As most say, you have the means of making what you need. Mild steel will be quite adequate for the job.

With a Vertical Slide, and an End Mill in the chuck, it should be possible to make exactly what you need.

It will be an interesting means of becoming familiar with the machine, and boost your confidence.

Howard.

Thank you to everyone who is contributing. I feel well eqiuiped now. Will, the drawing you posted is a great form of reference.

I'm opting to skim a small block of mild steel using the vertical slide. My inclination was to use a 4 flute cutter, however I have read opinions to the contrary. By drilling the bolt hole prior to skimming to alleviate the load (as Ian recommended in an earlier post), I thought a 4 flute end mill would be adequate and give a more refined surface finish. Given this will be my first milling experience, with a preference to making smaller passes.

I don't have any literature on milling so I'll be off to the library this week. Suggestions welcome.

Many thanks,

Tim