Myford Super 7 Tailstock Micrometer Dial

I was recently approached by a member of the Forum as regards had I done anything with the Tailstock dial on the Super 7. My initial answer was no, and that I did not foresee any prospect of doing such in the future. Not owning a Super 7 now would make the task harder.

George Thomas did an elegant solution to this problem some years back. A Tailstock Micrometer, chapter 14, page 160 of the first edition, "The Model Engineers Workshop Manual". While 0.300" per rev is fine for the Imperial user, although a little awkward as regards the tailstock barrel graduations, 1/8 th's. It was not so good when it came to a lathe with Metric units.

As is usual when a seed has been sown, an idea germinates. The initial problem with involving gearing in this dial is the need to keep the Dial small so as not to obstruct the handwheel in use. Normal reduction gearing would lead to an extra large dial.

The Eureka moment came when I was thinking about another problem. Speeding up the initial gear train then reducing it leads to a more compact Dial. Due to the reduction in bearing area on the face of the handwheel boss a needle roller thrust race has been added to make ejecting centres, arbors, etc easier. This is a worthwhile mod without the dial. An oilite bush has also been added to reduce the need to lubricate the bearing after assembly. An annual top-up should be more than adequate.

The metric dial is graduated 0-10 mm per revolution but has an inbuilt error of reading plus on the 10 mm dimension by 0.000127 mm. Over the entire barrel travel this would be nothing to worry about. The imperial version is graduated 0-0.500" and has no error, that is always assuming a theoretical pitch of 0.300" to start with.

Plans are however in hand to produce an article on these dials. Whether one of the ME suppliers takes up the manufacture of these dials then it is early days. For my part I want no part in this side of things.

Regards

Gray,

Nice one, Gray

MichaelG.

Gray,

What a neat solution. I built your Super 7 carriage handwheel a couple of years back and find it invaluable. I look forward to seeing construction details for the tailstock dial in due course. Where will the article be published? ME, MEW, or elsewhere?

Mike

Want one.

Michael and Mike,

Thanks for the compliments

As regards publication, I am a long way off from that at the moment. I never write about anything unless I have made the item myself and currently I am wading through the parts drawings. Plus I could do to source a donor Tailstock from somewhere to help with the photographs, it will all take time.

Regards

Gray,

Do you have any plans to fit it with a "resettable" feature?

Hello Brian,

I am sorry I omitted to say that the Dial will be able to be set to Zero at any point. The friction device has been proven over many years on my Myford series 7 Handwheel Dial design for the Carriage, or Apron handwheel. This is incorporated with the sleeve gear that rotates on the Tailstock Handwheel boss. The Handwheel boss needs to be machined by the way to 24 mm diameter. This is somewhat smaller than in the George Thomas design, hence why I used the needle roller thrust race.

Regards

Gray,

So, is this one for 'Steamer'? I have one of his excellently-produced versions of your saddle dial on my S7.

Perhaps...

Me too. I bought another when I traded up from a Mk1 to a Mk2 S7.

There appears to be two types of Tailstock fitted to the Super 7. A Mk 1 and Mk 2, can anyone shed some light on the differences between these Mk's? I would hate to restrict the design to fit only one type.

Regards

Gray,

Just thought I would update the forum on the progress of the Prototypes. I have been lucky in that John Slater has produced some lovely 3D images of the Dial conversion. I could not have done this project without his help, KWIL's, and that of Michael M who initially asked if I had done anything about the S7 Tailstock Dial. Which in turn started me thinking about the problem and this attachment.

I have also been told from several sources that the difference between the tailstock Mk's is all down to the position of the Barrel Locking Lever. Horizontal means it is a MK1 and vertical being a MK2.

Regards

Gray,

For those following the progress on this attachment. This week I have managed to cut all the gears for both versions of the dial. Today the dials were graduated, there are still 4 operations to complete them

The Imperial dial is shown after 5 turns and shows Zero, Although the photograph does not do it justice. The screw driver slot and the slit in the brass sleeve gear are in-line as they were before I started.

The Metric dial reads,30.50 after 4 complete turns, it should read 30.48, and it should read plus anyway because of the gear train.

Regards

Gray

Nice work Gray. I’m really looking forward to seeing the plans for this is print so that I can make my own copy.

Mike

Hello Mike,

Thanks for the kind words, the article is well underway but a photograph from one of my collaborators is needed to show the dial assembled before I can finish this off.

Regards

Gray,

The dial are now finished and ready to fit to the tailstock, hope you like them. I shall have to wait for a final assembly photograph, but no doubt they will come.

Regards

Gray

I've just checked the tailstock travel on my Myford 254 (metric version) and find it is 0.3" per rev, so I'm waiting with bated breath. Is it going to be in EIM or MEW?

Hi Duncan,

At the moment I cannot say which it will be, sorry. The 254 uses the same set-up as the S7 as regards feedscrew, but I cannot remember if the bearing piece screwed into the tailstock body the same. Or whether there was a spigot attached with capscrews. I suspect it could be adapted.

Gray,

It appears to be screwed in, on the parts list there is a reference to part # 11855, the S7 parts list refers to A2114 but they could be the same or very similar. No dobt I'll be able to improvise, or I could take the easy option of 300 divisions (thous) and a calculator!

Edited By duncan webster on 29/10/2018 09:26:42

Duncan I have sent you a PM

Regards

Gray,