(Early) Myford Super 7 Adjusting Collar

This topic has 10 replies, 5 voices, and was last updated 21 November 2020 at 18:17 by Jonathan Harraway.

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18 November 2020 at 18:00 #508278
Jonathan Harraway
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@jonathanharraway23319
I've just treated myself to a new cross slide feed screw for my Super 7, but it's not the same as my existing.

It's about an inch longer, and the adjusting collar binds a thread or two on.

I've got a MK1 S7 and assume I've managed to buy an feed screw for a Mk2. Do I just need a later adjusting collar (which are currently £996 on eBay from Myford!) or is there some other trick?

Thanks,

Jon.
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18 November 2020 at 18:00 #14094
Jonathan Harraway
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@jonathanharraway23319
18 November 2020 at 19:23 #508294
Tony Pratt 1
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@tonypratt1
Pretty sure the cross slide screw should be the same pitch & diameter, how about some photos?

Tony
18 November 2020 at 20:48 #508308
Jonathan Harraway
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@jonathanharraway23319
Thanks Tony,

Excuse the massive picture – it’s taken a while to get this far!

Original feed screw is on the left, new on the right. The fine thread at the tapered end appears to be different, as the adjusting collar won’t fit.
18 November 2020 at 23:29 #508340
Steviegtr
Participant
@steviegtr
I think you have bought a Super 7B wide carriage one. Don't know about the threads though.

If you can find the thread pitch you could screw cut the collar to fit , or buy a tap. Or die.

Steve.

Edited By Steviegtr on 18/11/2020 23:31:24
19 November 2020 at 11:16 #508417
Peter Sansom
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@petersansom44767
When you say early S7, how early. I have a 1958 S7, bought a Metric Cross slide screw in the 90's and the original collar worked fine. My understanding was that only the later S7 with Power Crossfeed used a different screw.

Peter
19 November 2020 at 19:24 #508570
metalfettler
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@metalfettler
Hi Johnathan,

The ridiculously high price quoted for the collar is a scheme denoting item out of stock. Relaxes to a more legitimate cost when stock is restored.

Regards, Les
20 November 2020 at 09:18 #508654
Jonathan Harraway
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@jonathanharraway23319
Thanks everyone for taking the time to reply.

Steve – The Seller assures me it's correct (and the length isn't a problem). He's confirmed the thread size, so I can make a collar if necessary.

Peter – Not sure exactly how early; but it has the original clutch so it's a Mk1. I've ordered a collar, which just so happens to be for the power cross feed machine, so I can confirm you're theory.

Les – I'd guessed that was the case. Myford seem to be a little low on stock for a few bits, I couldn't get the feed screw direct from them.

It doesn't look like I'm missing any known issue, so I'll just have to engineer a solution! I never though that owning an old lathe would involve as much fettling as old motorbikes – very naive!
20 November 2020 at 11:08 #508679
Peter Sansom
Participant
@petersansom44767
I will check thread on a cross slide screw in the morning. I have both metric and imperial, so one is also in storage. On Myfords web site you can get the year from the serial number.

As it is a Mk1 clutch yours was built between the start of the S7's and 1958, just prior to mine as it was built just after the clutch change, original headstock with sight glass and later clutch.

Peter
20 November 2020 at 23:48 #508857
Peter Sansom
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@petersansom44767
the Collar thread is 1/2" 26tpi.

Peter
21 November 2020 at 18:17 #509019
Jonathan Harraway
Participant
@jonathanharraway23319
Thank you so much for measuring that for me Peter.

Both shafts are threaded at 1/2"-26 – Perhaps one is a BSB and one a BSCy?

Anyway I've run a 1/2"-26 BSCy tap down the original collar and it now fits. Everything bolted together and working lovely.

Thanks everyone for taking the time to help. Jon.
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