Myford S7 headstock on ML7 bed

[Dave Jones 1Participant @davejones1]

Morning all,

Does anyone know if a Myford super 7 headstock would fit on a Myford ML7 bed? Would this fit and would there be any differences to the centre height? My ML7 white metal bearings are on the way out and I wondered if replacing the headstock was an alternative to replacing the bearings.

regards,

Dave

[Dave Jones 1Participant @davejones1]

[SteviegtrParticipant @steviegtr]

You could phone myford up. I think it's a Halifax No. Sure they would know.

[KWILParticipant @kwil]

Yes but you will need check centre height on tailstock as there may be some mismatch.

Edited By KWIL on 07/02/2020 11:42:42

[SandgrounderParticipant @sandgrounder]

Years ago, 25+, I bought an almost new condition ML7 bed with metric leadscrew that had been used as an optical bench where I worked, after a couple of years searching, no internet or eBay to help then, I bought a battered Mk1 S7 which apart from a few missing teeth on the back gears had a good headstock which after cleaning up and new gears bolted straight on to the bed along with the S7 tailstock and I'm still using it. However I don't know if all S7 headstocks would fit all ML7's.

[SteviegtrParticipant @steviegtr]

Measure your bed height. I have just measured mine. Which is a 1977 Super 7B. It is exactly 3 1/2" to centre. 88.9mm. Hope this helps.

Steve.

[Brian WoodParticipant @brianwood45127]

Dave,

The ML7R is a hybrid lathe with an ML7 bed, fitted with the ML7 cross slide/topslide, but a Super 7 headstock and tailstock.

I don't imagine Myford made a different bed for the S7 but KWIL's point on matching the centre heights between headstock and tailstock is relevant and it might pay you to fit both.

Regards

Brian

[Mike CrossfieldParticipant @mikecrossfield92481]

When I bought my early Super 7 twenty-odd years ago the bed was well worn, but it came with the remains of an ML7 capstan lathe. The bed on this was unworn (since it just served as the base for the capstan assembly). I believe the ML7 capstan lathe used a standard ML7 bed. I rebuilt the Super 7 using this bed, and it has served me very well ever since. If you want to go down this route, I.e. a Super 7 headstock on an ML7 bed, bear in mind that you will need not just the bare headstock but also the complete countershaft assembly, motor and double pulley, motor bracket, tumbler and change gears, banjo, covers and back plates etc. There might also be an issue with interfacing with the leadscrew, which may be a different diameter to that used on the Super7. If you have all these parts it’s pretty straightforward. Aside from checking tailstock height as has already been mentioned, the only other issues I remember were that the countershaft arm required a new fixing hole drilling and tapping in the back of the bed, and the mounting holes for the saddle rack were in the wrong places, and needed redrilling and tapping. This latter point may be related to the age of my Super 7 and/or the fact that the bed came from a capstan lathe.

Hope this helps

Mike

[HopperParticipant @hopper]

Posted by Dave Jones 1 on 07/02/2020 11:24:36:…

…My ML7 white metal bearings are on the way out …

Are you sure? The white metal in the ML7 bearings is about a quarter inch thick and can be rescraped many many times before they are worn out. You may have to file down the flat matching faces of the halves after a few re-scrapes.

Have you tried removing the shims between the two bearing halves to tighten them up?

[JohnFParticipant @johnf59703]

ML7's normally have a shim pack in between the main casting and the cap so you can peel a layer of .002" ??? then re-scrape the bearing to fit.

John

[Dave Jones 1Participant @davejones1]

Thanks to all for your help. Now I know it is at least possible I will look towards replacing the headstock with an S7 headstock and possibly doing the tapered roller bearing upgrade at the same time.

[SteviegtrParticipant @steviegtr]

When you say tapered roller bearing upgrade. Are you referring to the old twin white metal bearing headstock. As I am not aware you can do anything with the later tapered Bronze bush model.

[Brian WoodParticipant @brianwood45127]

Posted by Steviegtr on 08/02/2020 19:00:11:

When you say tapered roller bearing upgrade. Are you referring to the old twin white metal bearing headstock. As I am not aware you can do anything with the later tapered Bronze bush model.

KWIL wrote an article in MEW some while ago describing an upgrade to taper roller bearings in place of the rather vulnerable angular contact bearing that Myford used in the S7 headstock. It is completely successful and has served me very well for over 10 years without any adjustment from when I carried out the modification. I endorse the upgrade for those good reasons.

I know of two other owners who have also made the change, again with good results

Regards

Brian

[SteviegtrParticipant @steviegtr]

Ah yes I understand now. I was thinking of the front bearing. Not the 2 rears. Did not know that they gave any trouble. But I'm pretty new to the Myford.

Steve.

[Mike PooleParticipant @mikepoole82104]

Posted by Brian Wood on 07/02/2020 15:41:56:

Dave,

The ML7R is a hybrid lathe with an ML7 bed, fitted with the ML7 cross slide/topslide, but a Super 7 headstock and tailstock.

I don't imagine Myford made a different bed for the S7 but KWIL's point on matching the centre heights between headstock and tailstock is relevant and it might pay you to fit both.

Regards

Brian

to be a nit picker the ML7R has the Super 7 bed, headstock, tailstock and saddle/apron of the old non power crossfeed Super 7. The economies were made by fitting the cross and top slide from the ML7 and not fitting the clutch, the countershaft is unique to the 7R but can be replaced by the Super 7 clutch version. I think the idea was to consolidate the bed across the range and delete the old ML 7 bed and 5/8” leadscrew. No doubt an ultra nit picker will find something I have forgotten. Just remembered the leadscrew handwheel was also deleted on the 7R

Mike

[Chuck TaperParticipant @chucktaper]

Old thread I know but I found this helpful when I set out on my own version of this project.

As a direct answer to the OP.

I have just completed the fitting of a Super7 headstock (only) to an ML7. It appears to operate just fine and there appears zero difference in centre height. Only minor (approx. 0.5mm) adjustment to the horizontal element of the tailstock was necessary (well within the range of inbuilt adjusters).

I have retained the ML7 motorising unit (a cost saving necessity) so, for now at least, will have to live without the headstock cover. Otherwise (and subject to further testing and measuring) a straight headstock swop is valid.

If anyone is interested in hearing about the outcome of "further testing and measuring" I am happy to post further otherwise my work here is done!

Hope my experience (in this instance) is of some use.

Regards.

Frank C.

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