Where to get a bed regrind?

I was visiting an old friend the other day. he had just purchased a Myford Super 7, which he wants to overhaul. Bed wear was grim and I suggested he moved it on very quickly!

Despite my suggestion, he wants to get the bed reground and preferably hardened. Since Myford's demise, I would not have a clue where to get such work done and neither has he. So has anyone any suggestions and likely costs involved?

Andrew.

For grinding, Slideway Services at Coventry, Brian Caddy, he has a very good reputation.

As regards hardening I think he can forget that. Hardening is done before grinding so they can take any warp and twist out of it, so he's already undersize.

As it's a Super 7 he could always try Jim Marshall over at Lathe-Parts who breaks Myfords.

He doesn't normally sell beds but scraps them as they are too expensive to ship. I know a couple of folk who have popped over and gotten a far better bed and a lot cheaper.

Myford still do bed regrinding. (the new Myford company that is). They quoted me 495 Pounds for an ML7 bed regrind and 165 Pounds for the saddle regrind, just a month or two ago. I'll be getting out the scrapers.Cost of international shipping on top makes it ridiculous.

As regards hardening I think he can forget that. Hardening is done before grinding so they can take any warp and twist out of it, so he's already undersize.

That was what "Original Myford" told me when I inquired.

Any decent machine shop with a suitable surface grinder should be able to regrind a flat bed lathe - suitable meaning long enough travel to accomodate the length of the bed.

Nigel B

"Should" being the critical word.

There's a Super 7 bed on eBay UK right now for 150 Pounds, supposedly in excellent condition.

Wear that is acceptable to some may not be to others. If all you are doing is the odd spacer here and there a clunker may be perfectly acceptable. For high-end work a brand new machine may be just barely acceptable. Horses for courses.

Hello,

Pretty obvious that hardening should be done before regrinding. But I don't understand the comment that "so he is already undersize". This bed has never been reground, so I expect it could be hardened prior to regrinding, Or is the likely distortion will be so great that the "maximum permitted regrind" will be exceeded?

As a pure matter of interest, is there any figure for the maximum that can be taken off before the bed is scrap? I have seen an ML7 bed that has a large depression due to rusting, although the rest of the bed is rust free. The depression must be around 75 thou at the deepest. The owner is considering recycling it in the near future, seems a pity, but there you go!

Regards,

Andrew.

I did actually re-grind a Myford 7 bed about 10 years ago on a large surface grinder, the top surface & outside shears were not a problem but the wheel was too wide to re-grind the inner shears these were milled on a nearly new turret mill, the bottom shear surface was not machined.

All in all the job turned out well but a lot off faffing about.

Tony

Pretty obvious that hardening should be done before regrinding. But I don't understand the comment that "so he is already undersize".

Beds to be hardened were machined to have a bigger finish grinding allowance prior to hardening than soft beds, as hardening caused distortion that was subsequently ground out. Your soft bed was ground to finished size so, as it stands, it does not have the distortion allowance any more & so is "undersize" for hardening.

That was "Original Myford's" explanation to me.

Hopper - any machine shop in possesion of a surface grinder & cannot produce a reasonably flat surface with a reasonable finish should not be trading as such !

Nigel B

Again, "should" being the critical word.

The unhardened standard bed lasted, what, 50 years or more? How old is your mate? Is that not long enough for him?

YOu can grind down as much as you like, within reason, but will have to do additional work to realign the half nuts with with leadscrew if too much is taken off the sides of the shears. Also, the carriage will need to ground to match the new bed. No point in running old on new. This should include machining down the area where the catch plates sit in order to compensate for reduced bed thickness.

If the bed has that much wear he will need to look too at the cross slide. It will probably need regrinding, along with the dovetails on the saddle in order to be up to scratch on par with a reground bed. Also look carefully at the headstock bearings and spindle. If bed is worn out, they probably are too. Or at least need major surgery with a scraper and possibly machining down the matching faces to get enough closure.

Also if the bed is that worn, the leadscrew and half nuts probably are in similar conditions. All up, he needs to have a real good look at every aspect of teh machine before sinking 500 - 700 Pounds into a bed regrind. There could easily be another 500 pounds to spend after that. Quite possibly more. (Back gear teeth intact? Tumbler gear worn out? Tailstock barrel worn? Countershaft and bushes clapped out? Motor ditto? Chuck worn out? etc etc) Gets to the point that it might be better to flip it or part it out and buy a low mileage cream puff that is ready to use.

Edited By Hopper on 10/02/2017 01:56:59

Hopper ,

Where approximately are you located on this good planet of ours ?

I had a look at your profile but you don't state where you are and in one of your posts you mention getting a quolte from Myford but the international freight is to high so i guess you are not in the UK ?

Oz.

LOL , tell me about it. I'd have to say the ML7 I bought at a garage sale recently is the single most abused and worn out lathe I have ever seen. But it will fix up OK.

Andrew, Many years ago I had the bed reground on my previous Myford by my local engine reconditioning shop, they had a large overhead horizontal grinder capable of taking stonking big diesel cylinder blocks, so this was a piece of cake for them,
The bed on mine wasn't particularly worn or bent in any way, just badly scratched at the front end of the bed, a slow pass was taken over it and cleaned up on the first pass leaving a very nice finish, can't remember what came off but it was a very small cut.

I think the charge was about a fiver and equivalent to a head skim back then, so it may be worth checking out any engine reconditioning shops around you to see what machines they've got, I was quoted £40 for an alloy head skim recently, so I'd expect a similar charge on a larger iron casting.

John.

Hopper,

Have you tried Machine tool automation at Mona vale in Sydney ?

Ian.

Thanks XD I'll give them a bell on Monday. Although, I am tending toward just using the bed as is. There is about four thou wear on the top surface, just within spec to not need a regrind according to an old Myford brochure on reconditioning services. Similar amount on the vertical surface but I will get around that by doing the wide guide conversion to use the rear surface of the rear shear. Presumeably the four thou on the top surface can be taken up by twisting the Myford's licorice bed into shape.

Edited By Hopper on 10/02/2017 23:39:21

Presumeably the four thou on the top surface can be taken up by twisting the Myford's licorice bed into shape.

You will just end up with a twisted worn bed that way, rather than a straight worn bed. Only cure for a worn bed is to re-machine to take out the wear.

Nigel B