Myford Super 7 at SRS for only £395

[Bob McParticipant @bobmc91481]

Thanks again for your comments..much appreciated.

Phil asks a couple of pertinent questions and I can say that ..yes.. you do need another functioning lathe to tackle quite a few problems for the restoration and in my case there was a need to make a couple of special tools as well using my old working lathe.

Also ..yes.. I do have a need for the Myford when fully restored, even though my old Atlas works perfectly well for most purposes it does need quite a bit of operational familiarity to get the best out of it…and anyway it ain't a Myford!

Kwill asks about the original bed grinding and I believe he is right in saying that the feet were surfaced first and provided a reference for the bed grinding, and I gave this some thought before I decided to undertake what was a time consuming although satisfying process of scraping the bed since I certainly have not got the equipment to do a professional grind job and I used a method which I will expand on if I ever get round to doing the article.

There is also the concern of levelling the bed when bolting down to a surface, and…there will most likely be some twist that will arise from fitting the heavy pulley and motor sections so there will be a case for compensating for this as well even if the feet are perfectly aligned with the bed.

Thanks again for the comments which I hope I have answered without giving too much away…

rgds..Bob.

[Compulsive purchaserParticipant @compulsivepurchaser]

I picked up a ML7 in similar condition a couple of years ago – I was on a work job and spotted it bolted to a bench languishing in an old garage; I mentioned it and was told to take it away if I wanted it; I gave them fifty pounds for it as didn’t want to just take it for nothing. Everything was seized but it all came free. It hadn’t been used since the 70’s and even before then only very occasionally and once the rust was removed it had almost no appreciable wear.

Apart from the obvious new belts etc I only had to obtain a new micrometer dial, feedscrew and handles which had been damaged, and a new capacitor for the motor (and rewired it from the “twin and earth” complete with chocolate block connector mid length!)

Sadly I didn’t take any “after” photos and only have one when I obtained it. It is now with someone who is cherishing it again.

[Bob McParticipant @bobmc91481]

Dear All….

Sorry about the delay in getting back to the forum but a few distractions kept me from getting on with it…however hopefully I can now resume where I left off.

As you can imagine the lathe is quite heavy and I think I mentioned previously that I used a wheeled motor cycle lifter fitted with stout planking in order to move the heavy lump around and for lifting the bed so that it lay parallel to the surface plate which enabled me to roll the lump over onto the blued plate to check for flatness.

As a first check I used a precision rule to see where the wear on the shears was worst, laying the rule along the whole length showed that a dip occurred on the front shear around 10 inches from the headstock, the total difference in thickness was about 5 thou, this would cause problems with the saddle movement along the bed.

I would have had the bed re-ground but the cost was rather steep, my idea was to manually scrape the bed taking off only the absolute minimum of metal and if I made a pigs ear of it I could at least have it ground. At this point I have to admit that my skill level in scraping is not fantastic and I make no apologies for those who are determined perfectionists.

The idea behind scraping is that not only does it produce a good flat surface but it also provides hollows where minute quantities of oil can collect; if you have never done any scraping it is a good idea to have a look at u-tube videos and practice first before going for it.

The Utube video by Stephan Gottswinter is quite good and there are a number of articles on scraping in the Forum, which are useful albeit some members think its not worth it, too difficult, and not as good as grinding, and needs quite a lot of time and patience.

I would say that there is some truth in this but it depends on how skilful you are and whether you are looking for perfection; my opinion is that even if there are some discrepancies in the bed accuracy with amateur scraping this will soon be evident when the saddle is moved along the bed, if there is no lateral or vertical displacement when put in any position along the bed with no tight spots, I really think you are on to a winner.

I will also mention the articles in ME by Graham Sadler which provide some interesting methods in this area of Myford restoration.

The width separating the bed shears also needs to checked and the inner surface of the far shear provides a good datum for checking this.

So some pics of the process…

Bed de-rusted.

Checking bed thicknes.

Some more pics to follow in next post.

[HopperParticipant @hopper]

More critical than the flat top surface of the ways is the vertical surface that guides the carriage as cutting forces push it towards the operator. If your lathe is pre-1972, that would be the inner surface of the front way. And can be remedied by doing the wide guide conversion. The simplest way of doing this was outlined in MEW about two years ago. See articles under the byline of Pete Barker. Basically you put a strip of gauge plate on the back of the carriage so it bears on the rear vertical surface of the rear way that is unused and unworn.

But if your lathe is post-1974 and was made with the wide guide as standard, if there is more than 3 thou wear on that surface, Myford recommends regrinding. It could be scraped if you have the skills and a master scraped straight edge to match it to. It's not an easy job to do properly. By comparison, Myford allows five thou wear on the top flat surface of teh ways before regrinding is recommended.

[Bob McParticipant @bobmc91481]

Thanks Hopper…

I have read your posts on scraping which is much appreciated and thanks for mentioning the wide guide conversion which I did contemplate doing, however I just wanted to get on with the job and as it happened the guide verticals were in quite good condition…thanks for your knowledge in this area.

I have been having problems uploading the posts and it has caused the reply from yourself to come in between what I was about to put in the next posting..with a bit of luck this one may come through.

Checking bed guides.

[Bob McParticipant @bobmc91481]

Bob Mc.

Painting…undercoat.

[egaParticipant @ega]

Hopper:

My recollection is that the vertical shears of the Super 7 bed were gang-milled rather than ground. My own, which was professionally re-conditioned but not by Myfords, seems to be milled.

I suppose practice may have varied over the life of the lathe.

PS Good luck to the OP with his task!

Edited By ega on 02/05/2022 11:15:02

[HopperParticipant @hopper]

Posted by ega on 02/05/2022 11:14:33:

Hopper:

My recollection is that the vertical shears of the Super 7 bed were gang-milled rather than ground. My own, which was professionally re-conditioned but not by Myfords, seems to be milled.

I suppose practice may have varied over the life of the lathe.

PS Good luck to the OP with his task!

Edited By ega on 02/05/2022 11:15:02

Yes it may have varied. And sometimes if the vertical shears were ground with the side of a wheel, of the face of a cup or dish wheel, they can look like they were milled from the semi-circular marks left.

Either way, it is that vertical surface that provides the primary guidance for the tool bit. You can have five thou dip in the top flat surface of the ways and tool will dip by five thou, but will make only a tiny difference to the diameter turned due to the tool dipping that tiny bit below centre. But five thou of variation on the vertical surface of the shear means the tool moves away from the job by the same five thou, resulting in a ten thou difference in diameter of the job right there. That's why Myford allows more wear on the top surface than the vertical before recommending a regrind.

[HopperParticipant @hopper]

Bob Mc, looks like you have been busy with the scraper already. Machine is look a far cry from your earlier pics of the poor sad thing. Good stuff!

[Bob McParticipant @bobmc91481]

Bob Mc. Myford restoration…Saddle.

Thanks again Hopper & ega your comments much appreciated..

I should have said something to Twf who posted on the 06/04/22, it looks like the ML7 had similar problems to mine, would liked to have seen the final result .

So I looked at the Saddle and it was worn at the tailstock end by 8 thou, this measurement was with respect to the saddle ways, in order to measure this I put two precision ground bars on the surface plate and upturned the saddle so that the saddle ways rested on them, then using a dti measured along the slideway.

8 thou is quite an amount and I milled the surface, by the time I had done the actual amount taken off was a little more than intended, the problem this causes along with the scraping of the bed guides is that the saddle will now be lowered so that the rack & pinion may not be in proper mesh along with a possible problem with the leadscrew engagement.

[Mark RandParticipant @markrand96270]

The answer to the lowered apron on (non power feed cross slide) Myfords is to mill an appropriate amount off the top of the apron.

[HopperParticipant @hopper]

Or mill a bit off the saddle where the apron sits. But set it all up and check the alignment first at both ends of the leadscrew. I cant remember for sure but I think my Myford had fibre washers between saddle and apron when i got it. Presumably done in the factory for alignment. Also both the rack and the leadscrew brackts have enough slack in the screw holes to move up and down a bit if needed.

[Phil H1Participant @philh196021]

Can somebody please help on this bit? I can see how the saddle might have worn but I am not clear why there would be a problem with it if it 'mates' with the new flattened bed (using engineers blue).

Phil H

[Bob McParticipant @bobmc91481]

Hi Phil…

thanks for question.. when the saddle is worn it is the surface that sits on the bedways that is worn; with the bedways flat and the saddle surface worn, the area of contact does not occur over the full area, ie it doesn't 'mate'.

In this particular instance the end of the saddle surface nearest the tailstock end was actually 18 thou out, so it had a gap between saddle & bed at that end….. quite a lot out.

Here are some pics of apron, this shows the surface that needs milling….nb it ain't like this now!

As you can see its in a bit of a state and the Leadscrew clamp handle is quite corroded, so I fashioned a jig to hold it in my Atlas lathe to give it a good cleanup. Pictures in next post.

[Bob McParticipant @bobmc91481]

The L/S clamp handle wanted a good cleanup, a piece of 1/2 inch bar suitably bent and drilled to fit the handle screw was put in the four jaw and set up as centrally as possible, some emery paper and lubricant soon got it looking better than new.

As it was..

As it turned out…

[Bob McParticipant @bobmc91481]

Dear All…

I get the impression that my posts are showing that I am still working on the items posted, I can assure you the lathe is 90% finished and .

Anyways up…the lathe as it stands at present.

[Pete RimmerParticipant @peterimmer30576]

Posted by Phil H1 on 02/05/2022 15:45:13:

Can somebody please help on this bit? I can see how the saddle might have worn but I am not clear why there would be a problem with it if it 'mates' with the new flattened bed (using engineers blue).

Phil H

Saddles wear on the underside at the ends where they collect abrasive material from machining. Usually, the headstock ends are more worn. This causes the face to be convex and so shaped like the rockers on a rocking chair. It's likely that it would blue up quite well but that doesn't mean it's mating with the flat way just that it's printing blue like rolling a fingerprint. If your ways are worn, it's likely that you'll find double the wear in the underside of the saddle.

BobMc you're doing well but you should make sure that you never rely on one set of measurements when looking for wear if you have a means of cross-checking. You chould check your measurements by stoning the front machined face on the underside of the saddle lightly to remove any burrs then running a surface guage on that face with a dial gauge on the ways. That would have been a set-up face for the original machining of those ways.

You're right to be concerned about the saddle height being lowered. It will cause the weight of the saddle to be carried somewhat by the leadscrew and might cause finish issues with your work. You might well be able to skim the bottom mating face to bring the apron up, but don't try to do this on a machine with powered cross-feed or it'll cause the cross slide gears to bind.

[Bob McParticipant @bobmc91481]

Thanks for your post Peter,

Yes I did actually stone the underside of the saddle, it was one picture I didn't take and I can see your reasoning regarding cross checking.

If I understand you correctly the check I made was to blue the ways and move the saddle, I presume that would do the same job?, I also set up the milling operation so that the saddle surface was parallel to the saddle/apron interface surface pic below.

[Pete RimmerParticipant @peterimmer30576]

It looks like you have put a parallel on the worn way and are indicating off the parallel. There is a risk by doing this that you will find one end very low and the other end the highest point because it has teeter-tottered one way on the centre high spot. Blueing the ways and moving the saddle carries the same risk. When you take this sort of measurement, always hold down one end of the prism with the indicator on it, then press down the other end to make sure it doesn't rock. Of course since you have milled the underside by indicating the un-worn face then you will already have compensated for that. Hopefully you will have taken great pains to avoid clamping stresses whilst doing the milling it takes very little milling error to require a lot of scraping to correct, as I have discovered in the past.

How are the underside ways now Bob? Still in as-milled condition or did you then scrape them?

[Bob McParticipant @bobmc91481]

Thanks again Peter for your post which is much appreciated as this project was at about the limit of my engineering abilities and equipment.

I did make a custom fixture for the milling operation and supported the saddle using the two surfaces of the cross-slide, hopefully this would not have put too great a stress that would bend it out of shape whilst milling.

I used the saddle/apron interface as a datum surface which was the only surface available to set the work up on, I was contemplating scraping the surfaces after but opted for a stoning as my understanding of having a scraped surface is that a flat surface is needed to bear against it..

The motion of the saddle on the ways is quite smooth and there does not appear to be any rocking, or lateral movement with the gibs set up.

Again your advice is much appreciated and if there are any anomalies I would rather it be picked up now before I set the lathe on a solid foundation.

Milling set up..

[Pete RimmerParticipant @peterimmer30576]

There is no problem running two scraped faces against each other Bob and it would be preferable to using a stoned face. The upper face of a pair will benefit from heavier scraping or 'oil flaking' so it has pockets to retain oil. You wouldn't do the lower face such as your lathe bed because then the pockets would hold dirt for the saddl e to pick up as it travels over. Your scraping on the bed is not deep eough for that to be an issue.

If you have confidence in your bedway being straight and true you could fix it down and level it, then blue it up and use it as a reference for scraping. Be prepared if you're going to do this because although you've made an admiarble job of milling the bottom flat and certainly improved the geometry even after stoning, it would print up poorly when blued. They always do it's just the way things are.

I don't know what your location is but I could certainly give you some pointers and practical assistance if you're near me in Kent and in fact if you can get to Essex I did just discover that the guy I have bought several straight edges off (the only source of new cast iron references in the UK now afaik) will be running a week-long scraping course next month. If anyone is interested I can fish out a link.

[Bob McParticipant @bobmc91481]

Thanks again Peter,

I would indeed like to be educated in the art of scraping, unfortunately I live in Cheshire so thats a bit too far for me!

I will now press on with the post and show the refurbishment of the pulleys…and a few pics of the lathe again, I don't know what it is about the old Myford but they have a pleasing curvy shape unlike the new lathes of today which to my mind look like that could have been bolted together from sheet steel.

You may notice my on-off switch housing which I thought would complement the rounded change wheel casing, the one thing I am looking for is a 'snubber' circuit since there is a definite electrical flash when the switch is turned off…..anyone point me in the right direction..? it has to switch off the induction motor.

Pulleys..

cleaning up.

p

[HopperParticipant @hopper]

Posted by Bob Mc on 02/05/2022 20:08:37:…

…, I don't know what it is about the old Myford but they have a pleasing curvy shape unlike the new lathes of today which to my mind look like that could have been bolted together from sheet steel.

Yes that is one of the things I like about the old Myfords and before them the Drummond M-Type. The ML7/S7 series released in 1946 was one of the last vestiges of Art Deco styling that peaked just before the war. Would have been designed during the late war, still to pre-war thinking to some extent.

The modern square block machines just don't have that kind of style, and look as if all those sharp angular corners and edges would be murder on hands and knuckles. If I bought a new Chinese lathe, as good as they doubtless are from a practical standpoint, first thing I would have to do is take an angle grinder to that square boxy tailstock casting. And then probably carry on along the carriage and heastock!

Your old girl is looking great in the latest pics. A far cry from your starting point. Shows what can be done with a pile of rusted "scrap".

[Phil H1Participant @philh196021]

Pete,

Thanks for that explanation. I was assuming that the underside of the saddle was checked for flatness first but the rolling of a fingerprint is a good way of explaining the possible snag.

Bob, that looks like it has cleaned up very nicely. Slightly better than a boat anchor now isn't it?

Phil H

[Pete RimmerParticipant @peterimmer30576]

Posted by Phil H1 on 03/05/2022 03:02:18:

Pete,

Thanks for that explanation. I was assuming that the underside of the saddle was checked for flatness first but the rolling of a fingerprint is a good way of explaining the possible snag.

Phil H

It does catch people out. For small items like cross slides you put them on a flat piece like a surface plate and bang down on the four corners in turn with your hand. If it clacks there is clearance below. For longer parts just scraper the middle – your blue spotting will gain a patch of no contact in the middle and you just keep scrparing wider and wider until the blue reaches the ends.

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