Myford S7 old clutch

[JamieGParticipant @jamieg]

Hi everyone,

Reading here in the forum a recent thread about a Myford clutch reminded me of a problem I have with my older Myford Super 7 (SK6096) with the "first version" of clutch which I gave up using since its frequent requirment for re-setting. I have a 3-phase motor connected so I guess it is less sensitive to start and stop operations.

My question is: does the new clutch type fit (provided I can find one at a reasonable price) or is there any recommendation / modification I could do to improve the actual situation?

Cheers,

Giacomo / Sweden

[JamieGParticipant @jamieg]

[Brian WoodParticipant @brianwood45127]

Hello Jamie,

I looked into this some years ago.

I'm sorry to say the short answer is there is not a direct replacement by the cone clutch since a longer hollow bored shaft is needed along with the 4 step pulley to suit the later S7 lathes. I bought the complete kit from Myford Nottingham and have been very pleased with it.

Just a small running detail that solved a problem for me when an unpleasant shriek started to occur on engaging the clutch. A drop of oil on the mating surfaces of the cone stopped it immediately and made for a much smoother take up of drive.

The cone surfaces are all metal so there is no friction material to get contaminated.

Brian

[JamieGParticipant @jamieg]

Thank you Brian. I keep the clutch already oiled and have no problems in that sense. It just loose the grip after a while and I have to reset the cone.

If I understand you correctly, buying the complete new clutch is possible to install it in the older version of the Super 7. Correct?

Cheers,

Giacomo

Edited By JamieG on 23/01/2013 14:27:27

[Brian WoodParticipant @brianwood45127]

Hello again Jamie,

There is the difference in length caused by 4 pulley grooves [and the longer shaft to accomodate it] compared to only 3 grooves on your older S7, as well as the differing woodruff key positions to overcome.

I really think your best information can only come from the new owners of Myford in Halifax, they adverise in this forum at the top right of this page and in the magazines.

I bought [secondhand] an old style clutch like yours thinking it would fit my lathe, how wrong I was. It sits in a drawer glaring at me every time I go there!.

Brian

[DMRParticipant @dmr]

HI Jamie,
Your older S7 clutch should not need constant resetting. I would suspect that you have the same problem another chap had on here some 2-3 years ago. The adjusting screw inside the pulley wheel should have a second screw in the same hole acting as a locking screw. It is 1/4inch BSF which may be a problem to you, but I can sort one out if that is your fault/problem.

As to fitting a modern clutch, it is not all that sinister but it will cost you if bought new, and if you could obtain what you need. The new Myford owners in Halifax (RDG) do not advertise a complete-er assembly which is what you would need. The big danger in buying second hand is that you cannot tell if it is OK until you can fit it. Bushes and bearings wear out, but RDG have those. However, as the previous postings you refered to earlier, the bearings are difficult because of the powerful spring in the countershaft.
You cannot just buy a new countershaft with clutch and (different necessary) pulley, which RDG do advertise. In addition you would need the complete cast iron rocking assembly (which RDG do not have) that the newer clutch sits in including the clutch engagement lever and all ancillary bits on the rocking assembly.
Two covers would need modifying in addition. The primary belt guard outer cover would need a circular cutout (or a replacement inner and outer cover) as the modern clutch needs more space. And the secondary belt guard (lift-up cover) would need a modification to the countershaft cutout as the rocking action shifts a bit and the casting is a bigger diameter over the shaft. Note that a newer cover here is no good to you as it will not fit over the mandrel drip-feed oiler arrangement.
The lower casting carrying the motor – what Myford called the Countershaft Arm – is identical between old and newer machines. Do you have the Myford diagrams for your early assembly?

Dennis

Edited By DMR on 23/01/2013 21:44:26

Edited By DMR on 23/01/2013 21:48:08

[JamieGParticipant @jamieg]

First of all i must thank you guys for the help.

Alright. It looks feasible BUT it is 1 a sensible cost and 2 it involves quite few modifications.I have the original manual with diagrams but it refers to the new clutch type, so the previous owner got it somehow in a latter stage or something else happens. The clutch was locked so I guess it has not been used for a while.

The Super7 I have now substitute my previous ML7, it was stripped and restored with new belts, bearings, etc.

One thing I should mention is that my S7 has the 4 pulleys and not 3 as supposed by Brian's post.

BTW I just found here in Sweden a S7 with the new clutch. Maybe that's the best option. i must talk with the boss

Cheers,

Giacomo

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