Martin Cleeve’s Dog Clutch

[Andrew TinsleyParticipant @andrewtinsley63637]

I have been reading Martin Cleeve's book on screw cutting. I was very taken with his dog clutch fitted to a Myford.

In the fullness of time I would like to make a similar unit. Does anyone know if drawings were ever made available?

Regards,

Andrew.

[Andrew TinsleyParticipant @andrewtinsley63637]

[Martin 100Participant @martin100]

Not as I recall but an updated / reworked version was published in Projects for Your Workshop Vol 1 by Graham Meek and published by TEE Publishing – cost £13.95

[MuzzerParticipant @muzzer]

Meek's interpretation of this is available on the interknot.

Sorry, that's for the BH600. 

Edited By Muzzer on 30/03/2017 15:50:28

[Phil WhitleyParticipant @philwhitley94135]

I have always wondered what happened to the actual lathes he modified? I also read the book, brilliant man, and a brilliant peice of work!

[KWILParticipant @kwil]

There is indeed a version for the Myford S7 by Graham Meek. Tony Pratt and myself proved the drawings prior to publication and I have exhibited a non permanently engaged version at Sandown MEX. (See in Album)

Edited By KWIL on 30/03/2017 23:00:38

[Ady1Participant @ady1]

Our Nobby has modified one of his units

[Neil LickfoldParticipant @neillickfold44316]

Andrew, I was going to modify my Myford with dog clutch. But I put a 220V 3 phase motor on the lathe when the single phase motor died. As it has a tuning to breaking and acceleration when changing direction, I found that there is no need for the clutch. I can set the carriage position with a micro switch that stops the motor going forward and comes to it's rest quite quickly. Then, after retracting the tool, I turn the forward position switch to reverse. It goes into reverse until I turn it to the stop position. It stops within about 0.02mm or so on the micro switch.

Neil

[Andrew TinsleyParticipant @andrewtinsley63637]

Thanks Guys,

The microswitch idea sounds good! I am always a bit bothered by instant reversing in case the chuck comes off. I know it is only at slow speed, but the chuck / work inertia must still be a bit on the high side!

Making the dog clutch seems to be a most interesting project in itself, so I may well go ahead in the future, but will try the instant reversing first.

The references above are for a Myford Super 7, are there any snags with modifying an ML7.

Regards,

Andrew

[David JuppParticipant @davidjupp51506]

Graham Meek has a version of his clutch to suit the ML7.

[KWILParticipant @kwil]

Muzzer's posting with the LINK to the "interknot" regarding the BH600 actually has the picture of my Myford S7 version!!

THere are indeed many more versions for other lathes that have been drawn.

[Ian Newman 1Participant @iannewman1]

Hi,

The adaption is discussed over several articles in ME magazine – I don't know if these contain any more info.

Vol 143, issue 3557, date 18/3/77 p334 on

Vol 144, issue 3596, date 3/11/78 p1275 on

Vol 143, issue 3598, date 1/12/78 p1405 on

All the best,

Ian

[KWILParticipant @kwil]

The advantage of the Meek system is that the spindle does not need to be stopped and reversed to run the carriage back to start again, as the "single dog clutch" is used also to reverse the drive to the leadscrew with the spindle still spinning. The leadscrew clasp nuts stay engaged at all times.

[Neil WyattModerator @neilwyatt]

Graham Meek has sent me this photo, which may be useful:

Neil

[MuzzerParticipant @muzzer]

Slightly different approach is possible with Colchester lathes.

KWIL – the original(?) implementations such as Hardinge don't need to stop either.

Murray

[Andrew TinsleyParticipant @andrewtinsley63637]

Thanks gentlemen,

All information has been absorbed, looks like I need Graham's book before I start this one! It will be some considerable time before I will be able to do this job, meanwhile I shall have a good read up!

Thanks to everyone who contributed to this thread.

Andrew.

[Clive FosterParticipant @clivefoster55965]

I think Hendey originated and patented the single tooth dog clutch concept around 1900 -1910 era. Surprised how few machines used it even after the patent expired. My Pratt & Whitney has one, as do most of the big Holbrooks. Its a really nice system on a three shaft control machine.

Only unique thing about the Hardinge implementation is its ability to run at high speed. My P&W says de-clutch before engaging above 250 rpm or thereabouts. Holbrooks have similar speed limitations. Headstock off job on both if you shear the clutch dog. Fortunately usually fixable but a lot of heavy work to get in. Hafta do mine someday as its cleary suffered although still working fine in sensitive hands.

Clive.

[John Stevenson 1Participant @johnstevenson1]

Posted by Muzzer on 06/04/2017 19:22:26:

KWIL – the original(?) implementations such as Hardinge don't need to stop either.

Murray

A very good video showing the true concept.

As Clive has mentioned it's not a new concept at all, many lathes having some or all of the features.

Where machines like the Hardinge, Monarch and CVA score is that all the dog clutch is mounted in the headstock and is all hardened and running in an oil bath.

Most also have machined tapered dogs to ease engagement and also to provide a better form of drive than a pressed in pin which is and does come loose under prolonged use.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Clive Foster on 06/04/2017 21:41:46:

I think Hendey originated and patented the single tooth dog clutch concept around 1900 -1910 era. Surprised how few machines used it even after the patent expired.

.

Thanks for mentioning that, Clive … it has prompted me to look at the Hendey patents on espacenet.

I've also found this excellent little book:

Hendey : 1870-1920

https://ia800202.us.archive.org/2/items/cu31924003914110/cu31924003914110.pdf

MichaelG.

.

[quote]

PATENTS AND THEIR PROGENY

For some thirty years past the policy of the Company has been one of standardizing, the adoption of a basic line composed chiefly of the Lathe, the Shaper, and the Milling Machine, Throughout this period all possible concentration and study has been brought to bear upon original improvements, refinements, and betterments. Radical departure from the main line of accuracy, utility, and flexibility have,been discouraged and the Company's efforts have been largely focused upon the development of the principles and improvements embodied in Letters Patent issued to Eli J. Manville, Wendell P. Norton, Constant Bouillon, and George H. Knight. A patent, essentially a crystallized idea, is susceptible of development and progressive improvement. The Company's policy in this respect has been to market no betterment without a protracted period of practical experimentation, to the end that each refinement may in itself reflect Hendey Standard.

[/quote]

Edited By Michael Gilligan on 07/04/2017 09:36:20

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