Myford Lever Action Tailstock Design and Build

Excellent tips Hopper and very well put, just about sums up all the good advice given to me by Jim who taught me bench work. The point about not scribing too deeply is one that he laboured, but I've never seen it in print before. Jim seemed about a hundred years old when I was an apprentice and I only recently realised he was younger than I am now!

Watching this build log with interest still, keep up the good work.

Dave

Thanks Dave.

Yes funny how you remember both these old tricks and the old boys who taught them to you. I am the same. I can tell you exactly who told me what. Remember it clear as a bell. In the Swingin' Seventies of the youth rebellion against the older generation, those old boys seemed to be above all that and were held in high regard by pimple faced yoofs.

And funny when you think that now we are older than those old boys were at the time. I recently realised that our mentors aged say 60 in 1975, would have been born circa 1915 and started their apprenticeships circa 1930. So their 60 year old mentors would have been born in like 1870 and started their apprenticeships in 1885. The height of the steam engine era. So we were being told these kinds of things by guys who had been told them by the original living relics of the Industrial Revolution.

That connection and many of these little tricks will be lost when our generation is gone as there are precious few apprentices these days.

But does it matter? China has built up the world's biggest manufacturing industry from scratch without such hand-me-down traditions. But the quality levels of much of their machining and final hand fitting are not yet up to the standards of Rolls Royce et al, or even of Myford, Raglan, Boxford and co. Time will tell.

Very true about the memories, bit off topic but a box was recently unearthed that has been in store since my parents house was cleared years ago, in it were many parts I made at work for LBSC's Miss Ten to Eight locomotive. Part of it was a finished crank axle, loctited together and pinned,I had forgotten the box's existence and it was a real surprise when it was opened. But on seeing the axle I can now remember clearly the conversation I was having with my mentor Jim while setting it up on a surface plate for loctiting as if it were yesterday. until a month or so ago the box had been unopened since the firm closed and we were all made redundant, this was August 1979! 43 years ago.

Yet I have to have a picture of my cars licence plate on my phone as I cannot for the life of me remember it!

Or where I left the keys to it.

Dave

Edited By Dave Wootton on 25/03/2022 09:22:30

Edited By Dave Wootton on 25/03/2022 09:31:08

Lol glad to hear I am not the only carries a phone pic of his car number plate!

So are you going to finish that Miss Ten to Eight now you have it again?

Edited By Hopper on 25/03/2022 10:03:51

Anyhow, twas a day of watching the paint dry today. Got the first topcoat on over the primer. The rain has stopped so the humidity is a crisp 70 per cent so it might even be dry by tomorrow. Otherwise it will have to go in the oven. Not sure if a second coat would stick to already baked paint though. Painting really is not my thing. I do know from bitter experience though that if I spray a second coat onto still even slightly tacky paint, it will wrinkle up and do all kinds of weird things.

I used a tiny leftover bit in a spray can from when I restored the lathe some years back. It is industrial machine paint I had mixed up locally. Some website said RAL 7011 was the correct paint code. But it's not. It's a bit darker than true Myford grey. But what the heck, it's a bloody old lathe not a 1923 Lagonda.

So pottered around trying to work out the exact geometry to make the handle so it gives a full range of movement and does not foul the tailstock. Bit hard with a cardboard template and a bit of old flat bar. But I think I will definitely make the later type lever with the sliding handle. Otherwise it could be a bit in the way, right where I reach for my drill bits, tool bits and mikes etc to the right of the lathe.

So I will draw it up best I can from internet pics and the critical pivot pin locations Noel sent me and wait until I can bolt the actual units in place and make the handle final fit to the real thing. I think I will go one step further than Myford and add a spring loaded ball bearing in the bracket to act as a detente on the sliding handle. Put a couple of grooves in the handle to hold it in position at full extension and half mast. That might be rather handy and do away with the need to tighten/loosen the clamping pinch bolt every time I want to slide the handle in or out. Something to sleep on....

Afraid so hopper, was under the impression that castings and drawings would be hard to find as it's not an engine seen very much. However they are still sold by Kennions so a set of drawings and some very nice hornblock castings arrived last week, so it looks like another project joins the others. I had coated everything with Shell Ensis fluid which has done a superb job but after forty years is taking some shifting there's a very stinky soup of petrol and white spirit softening it up at present. Some of the smaller bits were in brown paper envelopes and they have rusted beyond salvation, presumably the acid in the paper,, and the original blueprints looked like the dead sea scrolls! I'll post some pictures and start a thread when it's all cleaned up, sorry if I'm hijacking yours!

Tailstock lever coming on a treat

Dave

Now why did I not think to photograph my car number plate? Doh.

To late now, no more car.

Not a lot of shed time this week. Resting up a bit. But actually did a small bit of machining, at last.

Using the three jaw chuck, I mounted up a peice of 3/4" plate that will become the handle bracket pseudo-casting. I faced a good 1/8" off one edge of it, partly so I have a good flat reference surface for the marking out of a quite complex shape. But also to get rid of any hard skin that black hot rolled plate like this seems to have. That was how i snapped the 6mm slot drill on the main tailstock body clamp. It was fine until just breaking through the surface on the other side. Hopefully this will get rid of any "skin" and give the remaining slot drill a chance to sail through it without dramas. The three-jaw works just fine for this kind of thing, in the absence of a milling machine. The centre "pip" is a bit off centre but no big deal in this instance. Interrupted cut is interrupted cut regardless. So steady steady wins the day.

So I have decided to bite the bullet and make the far more complex later/Super 7 type handle set up. First thing was a rough drawing I made up from measuring 'Net pictures on screen and a couple of essential dimensions, thanks again Noel.

Edited By Hopper on 31/03/2022 08:51:55

Edited By Hopper on 31/03/2022 08:52:55

Edited By Hopper on 31/03/2022 08:54:00

The drawing was scanned and a printed copy glued to a piece of Corn Flakes box and cut out with scissors. And lo and behold what materialised from the scrap box, awaiting its fifteen minutes of fame: a piece of 3/4" plate just the right size and shape! Magic.

The Corn Flake box prototype was tried out on the assembly in situ as "proof of concept". It looks like my interpretation of the net photos was spot on. The handle just clears the clamp on the fully extended position, allowing maximum quill movement of about 2-1/2" or so.

The long handle, a piece of 1/2" or 12mm BMS will go through the hole shown by the dotted line on the Corn Flakes special. That's CAD -- Corn-flakes Assisted Drafting.

And what would CAD be without a variety of viewpoints to make sure it worked from all angles?

And fully retracted, which is where most of the work will be done I am sure. I like the idea of being able to slide the handle back in out of they way of the adjoining bench as room is a bit tight and traffic a bit heavy right there. I might even add a GHT style ball handle to make the handle pinch bolt quick action, and maybe a spring loaded ball bearing detente...

The finished shape is more complex than the CAD model lets on. There is a 6mm slot to be milled where the link fits, a recess to be milled where it joins onto the quill clamp, to let the pivot pivot, and a slit to be cut on the handle clamp so the pinch bolt can pinch. This will actually be the most challenging part of the whole thing to make.

So the 3/4" plate has been cleaned up and given a coat of Hopper's Patented Marking Red. Once that has dried in the next day or two, the fun shall begin.

Edited By Hopper on 31/03/2022 08:56:38

Hey Hopper ! I think you may find using 12mm or 1/2" as your lever may be toooo thin ! The original was 9/16" and seemed ok but 12mm, no ! Your work looks very good. Best wishes Noel.

Thanks Noel. Yeah, I looked into that. But all I have in stock is 1/2" and 12mm round, and the plate I am making the bracket out of is only 3/4" thick, not 1" which is what I guesstimate the original to be, so wall thickness would be getting down on that.

I doubt that my mighty biceps will significantly bend a piece of 1/2" round steel bar a foot long to any permanent degree. The levers on my drill press are only about 3/8 or 5/16 or so and don't flex under bicep pressure at all.

If it turns out to be a problem, I can either bore out the bracket and fit 9/16 later or scrounge up a bit of 1/2" or so diameter chrome-moly round bar out of the centre of a 4WD utility truck shock absorber. Every mechanic shop around here has a skip full of them out the back. And I know I won't bend that stuff. They are tough.

Which brings to mind the ball that goes on the end of the handle. Looks in some pics like it would be 1-1/2" diameter, in others maybe a little smaller. And some pics seem to show a taper on the lever leading up to the ball. I will probably order a bag of five 38mm (1-1/2" ) black plastic machine knob balls off eBay for peanuts. .But they will have to come from Hong Kong and there is a two month imports backlog at Customs due to Covid. We are sort of at the peak of the Covid wave right now that the UK went through some months back.

So in the meantime will turn something up out of some 38mm aluminium bar I have. If my homemade ball turning tool will stretch that large. It was made to do the ball handles on the GH Thomas dividing head so not sure how big I made the max capacity. Otherwise, it will be an interesting job to turn the ball freehand and finish with a file,or a piece of 1-1/2" pipe sharpened to a cutting edge at one end that can be worked over the rough turned ball to make it truly spherical. I've always wanted to try that. I have a bit of 1-1/2" motorbike exhaust pipe leftover that would be perfect.

IN the long run though, I reckon the plastic knob wold be a bit easier on the hand than ally. I have a 1" plastic ball on the Myford carriage lock handle I made and you can really smack those things without pain. I like that.

Edited By Hopper on 31/03/2022 11:08:21

Edited By Hopper on 31/03/2022 11:10:02

Problem solved then!

No worries Dave. Looking forward to seeing it.

Hopper, You could make the handle with a female thread from your 3/4 stock that you have and make the thread on the end 12mm Male or bigger. The Original handle of the Myford one is ok for the intended light work, but is a bit flexy feeling if you were drill a 1/2 inch hole into something tougher than mild steel. A more beefy handle would be of a real benefit, although not in keeping with the original. Reminds me that I should get that round tuit out and make the heavier section handle myself. I'm just weighing up the easy option of heavier rod diameter, or going the flat plate shaped handle. Both being deviations from original. Cardboard design has a lot of practicalities, along with 3d printing test assemblies of parts too.

Thanks Neil. Guess I"ll be out in the shed testing my strength on various bits of bar this arvo. I do like the idea of the sliding handle though. I might have to scrounge up a bit of that chrome moly shock absorber rod after all.

Edited By Hopper on 31/03/2022 22:44:35

I mentioned the value of a non-standard handle end in my post (with photo) on 17 March.

The S7 version is 9/16" diameter. To keep the weight down at the outer end I step-drilled my replacement handle.

Thanks for the reminder Ega. Looks like a good alternative. Motorbike handgrips, of which i have plenty kicking around, come to mind.

Well, a research session in the shed today sees me leaning toward sticking with the half inch round bar for the handle. According to my measurments the overall length is 12" but 3" of that is the bracket I am currently preparing to make. So sticking a piece of 12mm round bar in the bench vice with 10" sticking out provided an approximation. With all my strength in one arm (not much these days!) I can deflect the end maybe a sixteenth of an inch or so. I reckon I can live with that. If I have to push that hard on a lever tailstock, I will either go back to using the standard handwheel set-up or slip a bit of pipe over the lever. Or if there is too much spring, which I am not convinced of, I will turn a new handle from a piece of 3/4" bar I have in stock and step the end down to half inch to fit the bracket I make.

Decisions decisions! Nothing is ever simple. I might even get an hour or so in the shed tomorrow to make a start on the bracket . Should get it marked out at least.

I expect you'll go for the Myford-style ball to begin with; I found it a bit hard on the palm of my hand and the replacement seems much nicer.

I'm fascinated by your faux castings!

Yes. It occurs to me that I could just cut a few small pieces off the length of 3/4" x 1/4" flat bar on the bench, weld two of them onto the end of the remaining flat bar to make a clevis to mate with the link, weld one small piece on the side to take the quill pivot bolt, whack a motorbike handgrip on the end and the job would be done in 15 minutes flat. That would make way more sense. So not sure why I bother...