Following on from this thread here LINK I am in the process of making both a 1929 sensitive drilling attachment plus my own copy of the original Myford ML7 lever action tailstock attachment. I am reverse engineering the latter from pics of the Myford original on the internet.

The plan so far: (Can you tell I once worked in the drawing office for three months?)

(Sorry once again about sideways image. Can't seem to fix it. Perhaps the mods once again could fix it, pleeeze?)

But I am short of a few critical dimensions. What I can't measure from screen pictures is the thickness of the link that goes between the tailstock body clamp and the main hand lever. I am guessing it would be a piece of flat bar about 3/4" x 1/4" (20mm x6mm) but not sure.

Also, I am unsure what size the pivot bolts in that link would be, and the third main pivot bolt that connects the hand lever to the tailstock quill clamp. I am guessing 5/16" but not sure. And are they just plain bolts, or are they shoulder bolts with a plain shank and smaller diameter thread?

If some kind person who has an original Myford lever attachment could measure the link's width and thickness and those bolts and let me know I would be forever in your debt. So far it is the only remaining stumbling block.

I have made a start already, digging a piece of 3/4" thick steel plate and similar alloy plate out of the scrap box and making up a couple of paper templates just as "proof of concept" so I know the material will be big enough. Turns out they are so have carried on making better drawings and laying out.

Both pieces are scabby old offcuts from the metal yard where they have cut these holes out of plate, hence the laser/plasma starting hole in each. The hex bar is to make the pivot bolts if they are not standard bolts.

Will be a bit of working cutting these out on my new horizontal bandsaw and doing the rest in the lathe as I have no mill. Happy days.

Edited By Hopper on 13/03/2022 11:00:21

Mod edit: rotated photo

Edited By SillyOldDuffer on 13/03/2022 11:03:04

Thanks Noel. That sounds great.No rush. I am off to bed here shortly in Upside Down World. 

I think the Super 7 link and pivot bolts are somewhat similar dimension, from looking at a million pics on the net. This, below is the one I am copying. I am also trying to work out what sized square bar to use to make the handle. The square where it attaches to the link looks to be about 3/4" square to me, but again not sure. Of course I have half inch and one inch square in stock (the scrap box) but no 3/4"!

And is the round part of the handle 1/2" diameter?

I have thought about putting the Super 7 type offset handle on it but that may have to come later.

Top view showing the black link and the three mystery pivot bolts.

Also am I right in thinking the adjustable stop bolt at the front would be 1/4" diameter?

It's been easy enough working out all the larger dimensions by setting photos so the hole in the middle of the main clamp is the known 2-1/8" diameter and measuring off the screen. Easy enough for things like the length of the handle and the link etc but impossible to be sure on the smaller diameters etc.

Edited By Hopper on 13/03/2022 11:21:20

Edited By Hopper on 13/03/2022 11:24:55

Edited By Hopper on 13/03/2022 11:37:38

Thanks Nigel. Following a message from another member, I am looking at making my own shoulder bolts with 5/16" plain shanks and 1/4" threads on the end. Will ream the holes to suit. Unless I find out the original Myfords did differently. Will be a while before I get to that stage so will wait and see what Noel measures on his original unit.

Thanks Dennis. I checked that out. It uses Heim joints for the pivots, which is probably a smarter more modern way of doing it. But I decided to keep mine traditional looking to fit in with my other antique machinery in Hoppers House of Heritage Horrors. Plus it looked to me like the Heim joints would let the handle wobble up and down loosely as the Heim joints move sideways as well as radially. Not sure about that. But it did give me some useful measurements re handle length etc.

A bit of progress today. Rough cut the outline on my new horizontal bandsaw, just making straight cuts with the job held in the vice with the saw in horizontal mode. And drilled and tapped the 1/4 BSW holes for the clamp bolt and depth stop bolt. Have not yet decided on what size to make the main pivot bolt that screws in the top of the this bracket.

Looks pretty 'orrible at the moment but an hour or less to finish it off on the belt sander and linishing wheel attachment on my 8" grinder will have it looking like a "proper" casting.

Thanks Noel. That's brilliant. Very comprehensive and helpful with all the details. Will keep you posted how it all goes.

PS, Noel, is this the type of lever tailstock you have, below? With the offset handle rather than the earlier straight handle? If so, one more question: What is the centre distance between the two pivot pin holes in the handle?

And is the handle shaft parallel to the line between those two pivot holes or is it angled back slightly? Cant tell from pics for sure.

I am thinking now that I might make this type of handle rather than the straight one in my earlier pics. Looks like the pivot bolts are closer together so more leverage given, and the long handle can be slid in out of the way or for less leverage on small jobs. There must be some reason they changed from the straight handle to this one??  Bit more of a fiddle to make, but I reckon I could fabricate it from two pieces of square bar welded together.

Edited By Hopper on 16/03/2022 01:41:17