Professional Machine Fettling

[Dr_GMJNParticipant @dr_gmjn]

All, I’ve got a Myford ML7 lathe and an Seig SX2P Mill.

Despite its age (and with some light fettling by me), the ML7 a very nice machine to use in terms of the feel of the wheels and how smoothly everything moves.

The SX2P on the other hand feels awful by comparison – either sticky wheels/slides, or too loose. Despite a lot of trying, I’ve never really found the sweet spot, and frankly can’t be bothered to mess about with it. It just about  manages to do what I need it to do, albeit with considerable swearing and tutting from me. Obviously it just dovetails and gibs, but I think it really needs the sliding parts scraping, and perhaps the gibs need attention too.

Question is, is there anywhere I could take it to have this done professionally, and if so what would be an approximate cost?

Thanks.

Edited By Dr_GMJN on 30/06/2023 17:34:29

[Dr_GMJNParticipant @dr_gmjn]

[BazParticipant @baz89810]

If you can find a professional outfit to do it I think the cost would be prohibitive.

[Anonymous]

Not many professional grade machine tools use traditional slideways and gibs these days. So finding a professional rebuilder will be tricky. Even if one can be found the cost will almost certainly be many times what the milll is worth. You may be lucky and some scraping will fix the problem. Or you might be unlucky and the mill will need some remedial machining.

Andrew

[Dr_GMJNParticipant @dr_gmjn]

OK, thanks both.

[HuubParticipant @huub]

Posted by Dr_GMJN on 30/06/2023 17:33:32:it really needs the sliding parts scraping, and perhaps the gibs need attention too.

Start by adjusting the gibs. Once these are OK, you can judge the "state of the ways".

Loosen the gib adjusting screws a full turn. Now the table should move smoothly without drag.
Just by using your finger tips, slightly tighten the adjusting screws without applying any torque.
The table should still move smoothly without drag.
Try to move the table over its full length. You may find it will take more "force" on the end due to wear and asymmetrical weight (table not in balance).

If this doesn't help, remove the gibs, clean and oil the ways and try again.

[JasonBModerator @jasonb]

Well I've only got one moving Myford item which is a vertical slide, yes it has a nice feel and action. But I don't find the Sieg and Warco machines which are obviously not built to the same level bad enough to what to get them reworked. I doubt what comes off them would see any marked difference in quality if they were but it depends if you want to feel your machines or use them.

If your wheels are sticky make sure you have not over adjusted the nuts in a quest to remove all backlash, I'd rather some backlash and free turning handwheels then no backlash and sticky hard to turn wheels.

[Dr_GMJNParticipant @dr_gmjn]

Thanks all.

It’s not so much the quality of the work (or at least accuracy – not being able to get a smooth linear movement sometimes causes finish issues on long parts or at each end of travel). As I said, it’s the feel of the machine when I’m using it that’s the issue. It’s clear that the ways are too tight, yet if I loosen them even a fraction, I can feel some slight rock in the tables.

Also, when I lock an axis, it changes the DRO readout, usually by 0.01mm. If I nip the locking bolt a bit, then set the position to the DRO, by the time I’ve finished machining a length, the reading has often changed by 0.01mm by the time I’m done. Also when the axis locks are released, it sometimes still drags, sometimes doesn’t.

Backlash on the z-axis is huge, and not insignificant on x & y, but despite trying all sorts of cures, I’ve resigned myself to live with it.

Without DROs I wouldn’t be able to use the mill to any useful degree. It would take hours to get one part right (it takes me long enough even with the DROs!).

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 01/07/2023 06:57:29:

.

but it depends if you want to feel your machines or use them.

.

Not really a binary choice, is it ?

… I see no shame in wanting both.

MichaelG.

.

[Anonymous]

Some thoughts:

There is a certain satisfaction when using machine tools that move smoothly and consistently. A machine tool ought to help one make good parts, not be a hindrance.

The DRO moving when an axis is clamped is a fact of life. On my vertical mill the X axis normally moves 0.005mm, rather more on Y. It's now automatic to position the table to compensate. Plus, my DRO is accurate to 0.01mm, so no point in sweating over the odd 5 microns.

The backlash values on my ex-industrial lathe and vertical mill are generally large, in the 0.1 to 0.4mm range. That doesn't worry me in the slightest. On the lathe one tends to move in one direction only and on the vertical mill I have a 2-axis DRO. No idea what the backlash of the knee is on the mill, but on the odd occasion when I need accuracy the movement is always in the same direction; and the dial seems pretty accurate.

The DRO on the vertical mill is probably the single most useful accessory I have ever bought. I don't have a DRO on the lathe, and don't miss one in the least.

Andrew

[Dr_GMJNParticipant @dr_gmjn]

Michael, Andrew,

Yes, that’s basically it – I do this as a pastime, and any time spent twiddling wheels would be more pleasant with a smooth action. I do use the machines for building, they aren’t just for show.

I wasn’t aware that other machines would change position, at least not perpendicular to the gib, so fair enough.

I don’t have DROs on the lathe, although often thought they would be useful. I’m just learning to overcome this using the saddle stop and slip gauges, or a DTI on the appropriate axis. No real issue there.

I suppose I’ll try adjusting the gibs again, but as with other endeavours like this, I invariably think for some reason I can sort it this time, but end up with exactly the same result, having wasted several precious hours. This is why eventually I throw the towel in and hope I can pay someone to do it.

Having said that, I had no issue at all hand flatting the ML7 ways and adjusting the gibs (when I converted it to a wide bed saddle), which avoided a re-grind and gave a huge improvement in feel.

Thsnks.

[Nick HughesParticipant @nickhughes97026]

Have a chat with

Blue Diamond

They should give you an idea of the cost, so that you can make an informed decision.

[Ex contributorParticipant @mgnbuk]

Reckon on £65 – 70 per hour + Vat for the services of a machine tool fitter. For a small machine a couple of days should do it, so 16 hours @ £65/hr = £1040 + Vat.

Nigel B.

[Dr_GMJNParticipant @dr_gmjn]

Thanks both. I was thinking it might be about £500, but if it’s significantly more than the price of a new mill… never going to happen.

I’ll have another go myself and put up with it I guess.

I wish there was an ML7 equivalent mill, the size of the SX2P. Even considering the price, I’ve never really been happy with it to be honest.

Did I read somewhere that some ex-Myford guys would come to your workshop and set up your lathe for you? I don’t remember it being a stupid amount of money, and presumably it’s the same kind of setup work they’d be doing? Not scraping beds, but getting the slides as good as they can be? Just a thought.

[JasonBModerator @jasonb]

But with new Myfords in the range of £10-15K you would be having to look at the £5-10K price range for a X2 size mill of similar build, Half way house would be a Wabeco 1200 at £3-5K. It's just a case of you get what you pay for and that fine fitting is included in the retail price.

[Dr_GMJNParticipant @dr_gmjn]

Posted by JasonB on 01/07/2023 18:12:27:

But with new Myfords in the range of £10-15K you would be having to look at the £5-10K price range for a X2 size mill of similar build, Half way house would be a Wabeco 1200 at £3-5K. It's just a case of you get what you pay for and that fine fitting is included in the retail price.

Yes, I was thinking more used price rather than new.

I think I remember someone saying that Arc Euro used to offer a fitting/fettling service for their machines, but they stopped doing it. I’m notoriously bad at mis-remembering things like that, but pretty sure that was the case?

[JasonBModerator @jasonb]

Yes they did but stopped quite a few years ago and sold more machines once they stopped!

None of my Siegs have been stripped and fettled like they show on their website.

[Peter Cook 6Participant @petercook6]

Random thought. Have you looked at the thrust bearings on the handwheels. I have an SX1LP and when new I couldn't get the feel right, either too stiff or too much slop/backlash.

I replaced the plain thrust bearings with ball thrust bearings and it made a huge difference.

I don't know if your SX2 has thrust races or plain bearings – but either way it might be worth a check.

[Ramon WilsonParticipant @ramonwilson3]

Doc,

I have today cleaned (as in dusted!) and photographed my Amadeal WMD 30RV mill with the intention of putting it up for sale. This will be in a day or so on here.

It's as new, in good order and has seen little use. It comes kitted out with lots of tooling, 5" vise, 4" tilting vise, 8" R/T (unused) plus loads of cutters etc etc

It does not exhibit any of the tendencies you describe with yours.

If you are mulling over possible upgrading then it may be worth considering.

Tug

[Dr_GMJNParticipant @dr_gmjn]

Posted by Peter Cook 6 on 01/07/2023 19:12:36:

Random thought. Have you looked at the thrust bearings on the handwheels. I have an SX1LP and when new I couldn't get the feel right, either too stiff or too much slop/backlash.

I replaced the plain thrust bearings with ball thrust bearings and it made a huge difference.

I don't know if your SX2 has thrust races or plain bearings – but either way it might be worth a check.

Thanks. Mine came with plain bearings, but I replaced them with rollers.

[Dr_GMJNParticipant @dr_gmjn]

Posted by Ramon Wilson on 01/07/2023 22:49:22:

Doc,

I have today cleaned (as in dusted!) and photographed my Amadeal WMD 30RV mill with the intention of putting it up for sale. This will be in a day or so on here.

It's as new, in good order and has seen little use. It comes kitted out with lots of tooling, 5" vise, 4" tilting vise, 8" R/T (unused) plus loads of cutters etc etc

It does not exhibit any of the tendencies you describe with yours.

If you are mulling over possible upgrading then it may be worth considering.

Tug

Thanks Ramon, I’m not familiar with that machine, but I’ll look into it tomorrow.

[JasonBModerator @jasonb]

Doc, the thrust bearings (not fitted to XP2) take side loadings not th erotating load of the bearings you replaced. It would need so thinking of how /if they could be fitted.

My 2.7 and 3 have them and I suspect the one Ramon has too as standard

[DiogenesIIParticipant @diogenesii]

..not sure what your Sieg gibs are like, but the 'on / off' adjustment that you describe can sometimes be due to adjusters or locking screws having raised a bit of a bruise on the back of the gib strip which subsequently interferes with the nose of the screw if the gib drags a bit or moves slightly.. ..intelligent dressing with a fine file sometimes helps.

Another cause can be if gibs end up dragging an edge along in the corner of the dovetail – again, I don't know if this applies to Sieg, but it can give difficult adjustment if present..

[Dr_GMJNParticipant @dr_gmjn]

Posted by JasonB on 02/07/2023 06:56:53:

Doc, the thrust bearings (not fitted to XP2) take side loadings not th erotating load of the bearings you replaced. It would need so thinking of how /if they could be fitted.

My 2.7 and 3 have them and I suspect the one Ramon has too as standard

I fitted thrust bearings and roller bearings to the shafts.

The thrust bearings helped a lot with backlash/smoothness  (probably more than the roller bearings), because you can pre-load them slightly with very little friction (unlike plain thrust faces).

The improvement was short lived however, because adjusting the gibs to give no free play stiffened the wheels up again. The backlash isn’t a big deal with DROs, it’s more the ‘sticky’ feel of the wheels that isn’t very nice.

I’ll have another go today. Presumably I’m aiming for zero rocking movement on a DTI when complete?

 

Edited By Dr_GMJN on 02/07/2023 10:22:29

[Dr_GMJNParticipant @dr_gmjn]

I spent an hour or so adjusting gibs this morning and it’s an exercise in futility. If the slides are anything like smooth, I’m getting 0.005”-0.010” of rocking play at the ends of the beds. This changes when the slides are locked, which of course doesn’t register on the DRO, so I’d be getting a large inaccuracy even before cutting any metal.

I’ll just have to live with it and accept (again!) you can’t polish a turd.

[Author]

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