Myford ML4 Restoration: Headstock bearings and spindle removal

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Jon Cameron on 06/05/2020 11:14:29:

Hi Michael,

That may be clearer than the windows snipping tool I used for the image posted above.

.

Here we go …

[ click image for full size ]

Nicely done, Jon

MichaelG.

[Jon CameronParticipant @joncameron26580]

Thanks Michael,

I have also posted the steady on a new thread, as it's likely to get lost in this one for anyone searching the forum via Google. It can be found here for reference. **LINK**

It'll also be posted on a couple of myford related facebook groups in the files section as the PDF. So is easy to find again.

Luke, I do have the materials in stock that were dug out the skip at work. so I could possibly get the steady to the point where you need to just make the fixing bolts and finger parts for it. I have already volunteered myself to make one, which is why the drawings were produced. Most of it can be made up on the pillar drill, but until i've got my lathe back together I cant turn the fingers, bolts, and base clamp for you.

Jon

[Jon CameronParticipant @joncameron26580]

Luke I think I've worked out why you may have been having issues parting off and with vibrations. Your bearings for the spindle have been installed back to front. The front one should be at the rear, and the rear one at the front. Have a look at the slots in the bearing, and the slots for the clamp bolts. Also the orientation of the grub screws, front and rear to the bearing shells as they were installed. The grub screws that you tightened up are there to locate into the tapped holes of the shells. Also get rid of that washer at the rear, buy two cheap feeler gauge sets from toolstation or similar, and use these to close down on to as you set the correct position. If your clever you can then sacrifice one set of gauges so that you still have a complete one and make up the gap using just one set once you know it. It looksas though the bearing shells have rotated in the headstock housing, therefore you will never be able to adjust out any of the play in the spindle.

I've just looked to see if there is a photo in my gallery but unfortunately not.

Unfortunately I only had chance to look over the photos tonight. 

Edited By Jon Cameron on 06/05/2020 21:15:24

[Luke MitchellParticipant @lukemitchell30627]

Hi again all.

I managed to order the wrong thrust bearing. I ordered a very similarly-size metric bearing and it was just too small. I've now found what I believe to be the correct size (1 x 1-5/8 x 3/8", often written FT1) and ordered one of those. That was a waste of £15, I shall have to think of a suitable project for it.

Jon, I know we've spoken elsewhere about your suggestion but I'd like to address it here so that others may benefit. I think that the bearings were installed correctly for two reasons:

1. The grub screws locate in small indentations in the outside of the bearings, the holes aren't visible on the inside.
2. The left-hand bearing has a shoulder that protrudes and abuts the casting. I don't think there is space for this on the right-hand casting as the bull gear/pulley assembly occupy all of the spindle.

This photo shows the protruding bearing shoulder. It's a bit covered in paint – which I will clean up when I get around to repainting the lathe – but the bronze is visible.

Brian, I've cleaned up the gear and will post a photo below. It has cracked all the way through and I believe it will need to be sawn + brazed, as per your revised instructions.

Regarding the lathe bed, here is a photograph of the condition of the gap between the ways on my lathe. They are definitely not an accurately-machined surface (although, as someone mentioned, they could become so with relative ease if I can find the right person/mill!).

The gap that I measured was between the ways themselves but it did occur to me, as I took this photograph, that the space below the ways could be used as a clamping surface. I'm not sure what this distance is as I don't have any telescoping gauges with which to measure it. Perhaps I was mistaken in my understanding and this is the clamping surface always used?

Finally, here is the lathe as it sits this evening. Hopefully I'll get the spindle re-installed soon – I've been spending a lot of time cleaning up all of the little burs, of which there are many!

[Robert Atkinson 2Participant @robertatkinson2]

The slits in the bearings chould align with the slit in the casting so they close together. The grub screws in the casting are not factory fitted. I'd suggest that at some time in the past the bearings have been rotated counter-clockwise by 90 degrees to compensate for wear and the grub screws added to allow compression of the bearing.
With the bearing rotated like this you need to be even more careful than usual when tighting the bearing clamp bolts becuse the bearings can't close and it will be very easy to crack the casting. The rotation of the bearings has also blocked the oil holes, on the rear bearing at least. The only path for the oil is through the slit in the bearing, but of course the oil will run out of the ends of the slit rather than onto the bearing surface. The slit is not even properly aligned with the oil hole.
Ideally you need a new pair of bearing bushes.

Robert G8RPI.

Edited By Robert Atkinson 2 on 07/05/2020 08:16:25

[Jon CameronParticipant @joncameron26580]

Hi Luke,

Yes as discussed, and shown above the bearings have rotated in the headstock, and there is no way to adjust the slack out of the bearings, and close them down onto the spindle.

Robert the grub screws are a standard factory fit item their position has changed from the earlier models but this is probably due to the amount of people suffering the cracked headstock, so the screws been off set help to eliminate a weak point with the two holes for oil and grub screw been in line.

As correctly said by Robert with the slit in the position shown there is a real risk of the headstock cracking, so check alignment of slit and grub screw/oil holes on reassembly, studying your photos that the posted a link to it would appear that the rear bearing doesn't seem to line up with the oil hole, although it could be just the angle the photo is taken, but these are my reasons for assuming the bearings have been installed front to back, and back to front, as well as been spun at an awkward angle for adjustment.

I was playing with my spindle last night, (nothing rude), and have managed to get my bearings, which are in much worse condition than yours, to vertical play of 0.0005", Horizontal play of 0.0045", and end float to 0.0005", runout is less than 0.0005", as sometimes my indicator shows it sometimes it doesnt. So still more work to do adjusting the bearings and bolts. I plan to remove the shims, and take out the 0.0015 one replacing it with layers of kitchen foil. to accurately build up the thickness. I then have some peelable shim which I will peel back to the right thickness and use under the clamps to set the correct gap for the spindle to tighten down onto. Still for a lathe that's 80 year old, and old bearings, original spindle, I don't think that's too bad at all. not brilliant and can be improved but not bad.

[Jon CameronParticipant @joncameron26580]

Posted by Luke Mitchell on 06/05/2020 21:57:17:

The gap that I measured was between the ways themselves but it did occur to me, as I took this photograph, that the space below the ways could be used as a clamping surface. I'm not sure what this distance is as I don't have any telescoping gauges with which to measure it. Perhaps I was mistaken in my understanding and this is the clamping surface always used?

Hi Luke, Above photo, the lower surface on the underneath of the beds ways, is the clamping surface the fixed steady uses on my lathe. mine measures 1/4" but is tight on two ribs so 3/16" may be a better thickness for the clamp. As with my reply above buy two feeler gauge sets from toolstation or similar, mine cost around £5 each. you can then measure the gap on the underside of the ways for reference, and use both to check the gap when reinstalling the spindle. been able to clamp the bolts tight down onto the gauges while checking the spindle still turns freely.

Jon

[Brian WoodParticipant @brianwood45127]

Hello Luke,

This gets ever more interesting. You and Jon have far more experience with these bearing bushes than I had. Dad never touched them other than to adjust for correct running. Neither he nor I fiddled with the grub screws and as Robert Atkinson has observed, maybe they need replacing. Certainly the slits should align with the split in the bearing housings, the shells will be unable to close otherwise.

I would be guided by the position of the oil holes as to whether they have been transposed at some time, but from the condition they seemed to be in as shown in your earlier pictures, they don't need replacing in my view, nor that of Howard Lewis; it is more a case of deciding if they have been mixed up and getting them back where they belong.

The cracked gear. Well now, it is so obvious once  the dog can see the rabbit. When you come to repair it you do need to ensure the tooth gap across crack [which you will have sawn out by now] is the same as that for the other teeth.

Measure adjacent tooth gaps with your calipers over the outside of the teeth and note the values. Then do the same measurement over the one to repair and adjust the value by squeezing it up carefully in your vice before you apply the heat and braze metal.

Do make sure you have a support below it to stop it dropping within the vice jaws when it gets hot.

Measured that way it is so much easier than trying to get consistency in the narrow gap right above the root of a tooth. I think you will find the gear has opened up slightly, the crack has width and will have eased some local stress. It is still a curiosity to me though !!

Kind regards Brian

Edited By Brian Wood on 07/05/2020 09:49:15

[Luke MitchellParticipant @lukemitchell30627]

Hi again all,

Posted by Brian Wood on 07/05/2020 09:47:33:

This gets ever more interesting. You and Jon have far more experience with these bearing bushes than I had. Dad never touched them other than to adjust for correct running. Neither he nor I fiddled with the grub screws and as Robert Atkinson has observed, maybe they need replacing. Certainly the slits should align with the split in the bearing housings, the shells will be unable to close otherwise.

I would be guided by the position of the oil holes as to whether they have been transposed at some time, but from the condition they seemed to be in as shown in your earlier pictures, they don't need replacing in my view, nor that of Howard Lewis; it is more a case of deciding if they have been mixed up and getting them back where they belong.

Brian, I've already repositioned the bearings so that the splits line up with those in the housings. Next time I work on the lathe I'll take some more photographs – I may extract the bearings again to double-check that they are positioned in the correct location but I am almost certain that they are.

Once the new thrust bearing arrives I'll reassemble and take some measurements to see if I've managed to improve things. I am quietly confident.

Kind regards

[Robert Atkinson 2Participant @robertatkinson2]

Jon,
I'm pretty sure the grub screws in he headstock castings were not factory standard fit. I have two headstocks, one has them and the other does not. There is no mention of them in the manual and there is no obvious purpose for them with a funtional bearing.

Robert G8RPI.

[Luke MitchellParticipant @lukemitchell30627]

Posted by Robert Atkinson 2 on 07/05/2020 15:56:53:

Jon,
I'm pretty sure the grub screws in he headstock castings were not factory standard fit. I have two headstocks, one has them and the other does not. There is no mention of them in the manual and there is no obvious purpose for them with a funtional bearing.

Robert G8RPI.

Hi Robert,

I've seen and read mention of these grub screws in many places – so many that I had assumed the machines were like that from the factory. My understanding is that the grub screws were used to prevent the bearing from rotating in the casting (which they seem to have failed to do on my machine).

Interestingly, during my searches, I've come up with lots of photographs of machines with these grub screws but lots of them do seem to be in different locations. Perhaps these are all after-market modifications!

See this photo (linking as it's not mine to post) in which the grub screw is just visible on the left-hand headstock bearing casting. See also this thread (on this forum) and this photo (also linking as it's not mine).

[Jon CameronParticipant @joncameron26580]

Is one of the headstocks cast as one with the bed? if so it wouldn't need the grub screws, as the spindle runs against the cast iron headstock. There is numerous examples that show the grub screws to retain the bearings from spinning. You only have to do a google image search to see them. There is also a lot spoken across forums about the inherent weakness across the oiling point and bearing retaining screw holes if you over tighten them.

I cant see that many examples of owners deciding off their own back to drill their headstock out and tap them for the BSF retaining screw. So although its not mentioned it is not to say that its not standard fit for the production. of myfords. Much as the adjusting screws for the half nuts are not mentioned but there still there.

[Jon CameronParticipant @joncameron26580]

Hi Luke thanks for the links, What's interesting to note is that the last lathe is an A1 which was built by Drummond allowing myford to concentrate on other manufacture. A1 and A2 denotes the ML4 and ML2 respectively. The position of the screws could be an indication of who built the lathe. Considering the second one, is another example of lathe that is missing the myford cast onto the side. and the offset position yet again of the grub screws in the same position as the last, could indicate these were both build by Drummond. Or at least in the later years of production.

[Jon CameronParticipant @joncameron26580]

Hi Robert, just had a look at your photos of the ML2 in your photos, It appears that it doesn't have the grub screws, but yours is an early version of the ML2, note the difference in the bolt arrangement for the headstock at the chuck end. yours isn't rounded off to meet the bed, but instead has two flats. earlier ones were bolted from above, yours seems to be bolted from underneath but still retains the older casting. If you wouldn't mind i'm compiling a list of myford serial numbers and differences between them all throu 1-4 types. Would you be able to tell me what the serial number of yourML2 is please?

[Robert Atkinson 2Participant @robertatkinson2]

Hi,

I didn't post any photos……
unless you are refering to my album photos. I've added  a photo of the headstock with added screws.

Robert G8RPI

Edited By Robert Atkinson 2 on 07/05/2020 17:04:23

[Brian WoodParticipant @brianwood45127]

Jon,

If it helps you in compiling your machine record, my Dad'd ML4 was purchased new in 1945 and sported the serial number D 2382.

That was stamped onto pretty much everything, even including the spindle around the hole at the gear end. It also included that 25 tooth gear.

Regards Brian

[Jon CameronParticipant @joncameron26580]

Robert yes sorry I wasn't clear, the ML2 in your album photos. If you don't mind as I said I'm compiling a list with a view to show differences and try and date the lathes, unfortunately Myford destroyed all the papers and records, including customer details and addresses, for the older lathes. Probably a wise move in this day and age of data protection but sadly does nothing to date the old myfords.

Brian, that's very helpful, if you happen to have a picture or can show some differences, your dad's lathe with that info dates two others from the myford Facebook group. I now have two dates one for lathes starting LH, of which mine is, and yours which means I can date five of the lathes I have serial numbers for with a fair degree of accuracy. It's all jotted down at the moment and I need to get it digitised along with photos to show the various differences such as the headstock changes from bolting from the top into the bed, then later bolting into the headstock through the bed. A long mission an I did post on the forum but haven't recieved much response in regards to serial numbers or photos of lathes.

So far with regards to serial number stamping, I have seen it on the leadscrew end, base of the headstock, saddle, cross slide, tailstock, and obviously bed too. I suppose it made sense with the volume produced that everything had a serial number so headstock and tailstock didn't get mixed up ect. 

Edited By Jon Cameron on 07/05/2020 22:35:08

[Brian WoodParticipant @brianwood45127]

Hello Jon,

In your last post on 7th May you asked if I might have a picture of two of Dad's old ML4 lathe.

Alas no. Photos of machinery were less common in those days, film cameras and expensive processing were the order of the day and sadly it simply didn't occur to me to record things in that way.

Sorry I can't help any further with compiling your record of these earlier lathes.

Kind regards Brian

Edited By Brian Wood on 09/05/2020 10:17:39

[Brian WoodParticipant @brianwood45127]

For those who were following this thread closely.

This is really to record my changed attitude to the question of nose registers about which David Bennett made a bold and somewhat controversial statement, in this thread, that the horizontal register was in fact not necessary.

Being traditional in my view of these features I challenged him but he has produced some convincing evidence to support that what he stated holds water.

In particular I suggested he turned a faceplate round and mounted it in reverse on the nose. This he has done, butting up to a machined collar behind it that abuts only the vertical register . Lo and behold , it runs perfectly true mounted in this way, despite the lack of any horizontal register. This also was the case found by Tony Griffiths of lathes.co.uk fame with at least two chucks and by David with two chucks of ML7 nose location screwed directly onto his ML4 nose. All these ran true even under heavy working and supported with his knowledge of a Wolf-Kahn lathe that uses only the vertical register for chuck location.

So, it would seem that a holy grail has been punctured. The truly critical location is the vertical register, the horizontal register that we have all striven to get exactly sized over the years is acting as little more than a guide.

Of course, with the increasing use of camlock location on hobby sized equipment, it has been used industrially for many years, the whole discussion might be regarded as academic. I apologise to Luke Mitchell for hijacking what was his thread, but it might be interesting to see what others make of this interesting new evidence

Regards Brian

Edited By Brian Wood on 11/05/2020 14:51:42

[Jon CameronParticipant @joncameron26580]

Hi Brian,

That's how my lathe has "registered" its chuck on a vertical face behind the thread, the thread been a guide and then the vertical face holding the backplate true to the front faced surface for the chuck. Although ive not turned any large diameter, it seems that ive been able to machine quite happily the smaller items I have done.

I believe my spindle has been modified at some point in its life from 1.1/8" to 7/8" 9TPI, perhaps to use existing tooling, the register has nearly all been turned down, sadly. There was an article from Martin Cleave in ME about the large bore conversion he did for his ML4, which would show the dimensions of the nose thread and any register, either vertical or horizontal. Wish we knew where his lovely lathe was today.

Regards

Jon

[Brian WoodParticipant @brianwood45127]

Hello Jon,

I don't like to correct you but, Martin Cleeve's lathe was I think an ML7, not ML4. Like you it would be interesting to know where his lathe fetched up; hopefully with someone who would have appreciated it in it's modified form

And yes, David's work has shown that a reasonable fit on the thread, to stop the chuck actually flopping about, backed up by solid contact with the vertical register does the business. So press on as you are doing!

Kind regards Brian

[Jon CameronParticipant @joncameron26580]

You have me wondering now, I'm sure the article was written to convert the 3/8" bore upto a 5/8" bore, so that 1/2" stock could be passed through the bore. I'll have to hunt out the article

[Brian WoodParticipant @brianwood45127]

Hello Jon,

It would be useful if you can find the article. If your memory of such material is anything like mine has become, you may find it is nothing like what you think it was !

By the way, the spindle bore on my ML7R is a nominal 5/8", in common with the standard ML7.

Even the ML4 had a bore greater than 3/8" surely? With a spindle diameter of 1 inch, that leaves plenty of wall thickness and enough to contain the 2MT socket that the later version such as my Dad bought were equipped with.

Kind regards Brian

[Luke MitchellParticipant @lukemitchell30627]

Just to chip in, I have measured my spindle bore as being slightly greater than 15mm. A piece of 15mm diameter stock will pass through easily. I suspect the bore of my ML4 is also 5/8" (15.88mm) although I've not measured it so accurately.

[Jon CameronParticipant @joncameron26580]

Hi Brian, Luke

Ive found the article by Martin Cleeves. It is indeed for an ML4, my spindle has the earlier spindle and nose thread of 7/8" 9TPI, therefore it only accommodates an MT1 taper and passes 3/8" stock. Below youll see a scan of the article, which also shows a grinder attachment for the rear of the lathe spindle. Something handy if you only have the one motor, though not recommended as the dust and grit would not do your precious lathe much good. Though the rest would be handy for setting up in front of a bench grinder, to assist with grinding HSS, or Carbide tooling. Something that Luke might like to look into for his tool grinding, it is certainly something ill be doing.

[Author]

Posts