Myford ML7 Headstock bearings

Hi, I just bought a ML7 and the spindle had a giant play. when I removed the bearings caps I found two shims made of paper stuffed along the metallic shims.

I measured the shims with a dial capiler and all four is near the .4mm mark. the paper was .2mm thick.

I removed the papers and kept only the mettalic shims, the play has gone, but the spindle was hard to turn by hand.

I mixed some lithium grease with prussian blue, carefully spread the blue to a thin flim in the spindle bearings surface and...

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Note the blue just touched the upper half bearings ons the sides and nothing in the middle. the lower part had contact almos ins all surface.

what sould I do?

Reply to
luizdiefenbach
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Put the paper shims back, sell it and buy a Boxford ?

Reply to
Boo

I mean how can I correct this problem? Can I scrape only the upper half of the boths bearings, so that way the lower part retains the aligment of the spindle?

Reply to
luizdiefenbach

If it's got the original white metalled bearings (babbit) then I doubt there's enough metal there to scrape so your options are to either re-metal the bearings or replace the spindle and bearings with the updated parts from Myford which converts it to bronze bearings and, I believe, a hardened spindle. Martin

Reply to
Martin Whybrow

The best approach depends very much on how much money and effort you want spend on the machine. That, of course, will be influenced by the rest of its condition. It's all too easy to end up throwing good money after bad.

Reply to
gunsmith

Twaddle. They are not lined steel shells, but solid, about 1/4" thick. It is hard to know why the machine was like that, unless the upper halves have been replaced but not fitted properly. I see nothing to be lost in fitting the top halves by scraping.

Reply to
Charles Lamont

Re-scrape the top halves with a bearing scraper until you can get good contact over most of the bearing without the shims. Then replace the paper shims with ones made from layers of aluminium kitchen foil. use enough layers so the mandrel will turn by hand when oiled, without significant effort and the total movement on the mandrel is less than .02mm when pushed up and down with about

20N of force.

You can get replacement shim packs from Myford's, but the kitchen foil works as well, if not better, since it is .02mm rather than .05mm per-layer like the Myford shims.

That should fix the problem.

Mark Rand RTFM

Reply to
Mark Rand

I'm not a Myford person, but as well, if not better, since it is .02mm rather than .05mm per-layer like the

For bulking-up, use beer cans, which are mostly between 0.08 and 0.20 mm (eg Stella cans are about 0.10 mm thick, and surprisingly even considering how they are made, by drawing - the one I just measured was between 0.102 and 0.104 mm over most of it's surface, as was a second can).

You can cut them with scissors, but ask the wife first.

-- Peter F

Reply to
Peter Fairbrother

In that case Charles you've seen a Super 7 or an ML7 that's already been modified, original ML7s have white metal bearings, fact! Martin

Reply to
Martin Whybrow

In case you doubt what I'm saying Charles, have a read of the ML7 spares list here

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, look at the 4th and 5th items on the list. Martin

Reply to
Martin Whybrow

Charles is perfectly correct. The ML7 headstock bearings are not thinly Babbitt lined steel shells, as used in automotive crankshafts. They are solid Babbitt. Plenty of room for scraping if the mandrel accidentally wears larger:-)

Mark Rand RTFM

Reply to
Mark Rand

I realised very shortly after I replied that that's what Charles was saying. I stupidly assumed he was saying they all had solid bronze bearings. I guess I should remember that usenet and several beers do not mix! Martin

Reply to
Martin Whybrow

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Reply to
ac080938

Kitchen foil - what a good suggestion. My ML7 is well sorted.

Reply to
BenA

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