Myford ML4 restoration, setup, upgrades………improvements???

[Jon CameronParticipant @joncameron26580]

First attempt at making an oil cup, hasn't gone so well, removed 7thou too much from the end that goes into the headstock so it's a loose fit. Not good! Will try again, though this one has at least sorted out what steps I need to take and what order, so the next two will be quicker.

Could have sworn I'd taken more photos, steps I took were to face off the large end of the blank, then turn the outside so I had a good finish, this was then spot drilled, then drilled with a 7mm bit then stepped upto the large taper drill you can see in the photo bellow. This has a tapered point to it and left a nice chamfer to the edge no need to bore it.

The blank was then turned and trued up in the 3jaw, parted off to length, it needed packing one side to run concentric with what I had turned on the outside, I stepped the edges turning the nub on the end to what i thought was final diameter, and then proceeded to turn a cone on the end towards the nub. This was then drilled with a 1mm drill bit.

 

 

Edited By Jon Cameron on 03/10/2017 18:12:30

Edited By Jon Cameron on 03/10/2017 18:13:10

[Martin NewboldParticipant @martinnewbold]

Can the ML4 side side screw and gearbox be retro-fitted on a drummond the base of yours looks very similar

[Jon CameronParticipant @joncameron26580]

Hi Martin, I couldn't tell you I'm afraid, I'm fairly new to machining and the different types of lathe.

If by gearbox, you mean the change gears, the bracket is a plain casting, using a 1/32 pin to engage the gears with one another. The back of the bracket is a plain smooth side, so if the lead screw bracket is a plain smooth side then I assume that technically it could be retro fitted, as could a ML7 or ML10 bracket. The change gears are mounted onto studs which are bolted to the bracket.

If it's any help centres on the lathe are 555mm, and the bed is 74mm wide, the headstock is mounted via three bolts to the bed. The bed has angled ways flat top.

Anything I can help with just ask. If I know the answer I'll happily give it. But this is as much as I can say with what you've asked above.

[David Standing 1Participant @davidstanding1]

Jon

Do you know why you had to pack your chuck out?

Is it a chuck issue, or is the tailstock out of line? (and i'm guessing the latter, given that it has been off, and the known problems with aligning the ML4 tailstock).

I would be wanting to get that sorted before I started doing any jobs on the lathe.

The other option, if you can't get the tailstock in line with the chuck, would be to use your four jaw chuck for truing up the work to turn it after it has been drilled in the tailstock, rather than packing out the jaws of the three jaw.

That's not a criticism, just that you will be handicapping yourself with it like that

 

 

Edited By David Standing 1 on 03/10/2017 21:48:10

[Jon CameronParticipant @joncameron26580]

Thanks David, I had turned the diameter of the top part of the oil cup, when I turned it around in the chick, (and since I don't have a dial indicator yet), I used the parting off tool to check alignment, I found that it was running out on one jaw. I cut a piece of coke can up and skimmed that jaw, it then ran true. So I'm 5thou out on my 3jaw. Then I proceeded to turn the rest of the lower half, now that it was running concentric to the top half.

It's not really a handicap, so long as you know about it, and can fix it with a cheap can of beverage. I've noted which Jaw it is, and once I have a dial indicator, (totally skint lately), then I can try dial the chuck in and get it more accurate. For a part such as this it wasn't so critical. It was my error that it's been made too small, 3 and a half turns (indications) too many on the dial indicator turning the final diameter.

[David Standing 1Participant @davidstanding1]

Jon

I misread your earlier post. I thought it was the external diameter of the piece was out of line with the hole drilled by the tailstock drill.

Having to pack the jaw out would irritate the hell out of me!

Are they matched (and numbered) jaws?

If one jaw is out of line with the others, you won't be able to 'dial the chuck in' on a three jaw chuck, unless it has a Griptru type adjustable backplate.

You can, however, get the jaws ground back to true.

[Jon CameronParticipant @joncameron26580]

The Chuck is what came with the lathe, a Crown chuck is the make. The Jaws are numbered and they are in the correct place. I took them out to clean when I got the lathe and put them back in starting with number 3. Ie reverse order of disassembly.

For more accurate work I have a four jaw with inside and outside gripping jaws. The three jaw has a reversible set. It's out by 5thou at my measure, which so far has been wrong. And there's three bolts onto the back plate. So I should be able to loosen them and tap it into alignment, with luck. If not packing one jaw each time isn't too bad. Just takes a couple minutes longer.

[David Standing 1Participant @davidstanding1]

Posted by Jon Cameron on 03/10/2017 22:47:45:

The Chuck is what came with the lathe, a Crown chuck is the make. The Jaws are numbered and they are in the correct place. I took them out to clean when I got the lathe and put them back in starting with number 3. Ie reverse order of disassembly.

For more accurate work I have a four jaw with inside and outside gripping jaws. The three jaw has a reversible set. It's out by 5thou at my measure, which so far has been wrong. And there's three bolts onto the back plate. So I should be able to loosen them and tap it into alignment, with luck. If not packing one jaw each time isn't too bad. Just takes a couple minutes longer.

That is basically the principle of Griptru adjustment, but if your bolts are on a countersink or very tight in their holes, it may just try and go back to where it was.

But, nothing to lose…….unless it ends up 10 thou out rather than 5 thou

[Jon CameronParticipant @joncameron26580]

Technically speaking I don't think it's possible in a 3jaw, surely the angle of the 3jaws would mean if I shimmed the wrong jaw, then it would be more like 6thou? Each of the other jaws been 2/3rds the distance from the jaw that's out. I know my maths are rubbish on that and im ready to be corrected by someone who is better at maths than me.

 

You are quite right for a four jaw self centering though. It could be anything from 5-10thou out. Depending on which Jaw you packed??????

Edited By Jon Cameron on 03/10/2017 23:11:37

Forget this, I've just reread your post! Yes you are quite right!!

Edited By Jon Cameron on 03/10/2017 23:12:57

[David Standing 1Participant @davidstanding1]

Jon

It is also worth remembering that by shifting the chuck around on its backplate (even if the bolts/screws allow you to do that), all you will be doing is moving the chuck on its axis of rotation.

This may then put the chuck body out of balance, something you will not want.

If the chuck body is true to centre, and the other two jaws are correct on centre, the only way to correct your issue is by grinding all three jaws together to bring them back on the lathe centre.

You might of course find a spare set of jaws that are true, but that is a long shot!

[Jon CameronParticipant @joncameron26580]

Hmmmm I see your point!

I don't fancy grinding jaws down though, I read somewhere else that someone had ground the jaws of their 3 jaw, all was working well, about a year later they had tried to center up a bar in the chuck and it wasn't gripping properly, the grinding had rectified the alignment issue but removed the case hardening on one jaw, this had the effect of softening that jaw to the others, every time the chuck had been done up the jaw (with now softer metal) had been squished. This meant that the jaws again weren't in square and alignment. I'd rather just pack each time I need to with a piece of drinks can. I plan to use the 4jaw going forward, once i have a dial indicator which should eliminate the issue.

Jon

[Brian WoodParticipant @brianwood45127]

Posted by Jon Cameron on 03/10/2017 22:47:45:

The Chuck is what came with the lathe, a Crown chuck is the make. The Jaws are numbered and they are in the correct place. I took them out to clean when I got the lathe and put them back in starting with number 3. Ie reverse order of disassembly.

For more accurate work I have a four jaw with inside and outside gripping jaws. The three jaw has a reversible set. It's out by 5thou at my measure, which so far has been wrong. And there's three bolts onto the back plate. So I should be able to loosen them and tap it into alignment, with luck. If not packing one jaw each time isn't too bad. Just takes a couple minutes longer.

Hello Jon,

Just poking my oar in here. Jaw assembly in a three jaw chuck, irrespective of make is always started by fitting jaw 1, then 2 and finally 3

I hope you will find that corrects the error you have observed. It is certainly worth testing that before shuffling the chuck with respect to the backplate—if it has been properly fitted into the chuck register that shouldn't even be an option.

Regards

Brian

[Jon CameronParticipant @joncameron26580]

Ah ok, I'll try that and see what happens. Thanks Brian.

[Jon CameronParticipant @joncameron26580]

Hello all, today I've spent some time looking over the headstock. When my lathe headstock started making a knocking noise, I was a not concerned and nipped the bolts up.a little. After a number of warnings about the cracking of the headstock and some advice given on how to avoid it. I made a start with two sets of feeler gauges from screwfix. I bought these for £3 each. So I could have a varied range on sizes for each bolting point. Then took the chuck off the spindle and removed the drive belt, setting the spindle up has to be done without any preloaded side force.

I slackened off the grub screws on the top of the casting next to the oil pots, then undid the bolts that tighten the bearings.

Working one at a time I started on the rear bearing, the method was the same for both anyway. I tightened the bolts down onto the castings using just my fingers, then inserted the feeler gauge built up to take up the gap, removing one thou at a time from the feeler gauges, tightening the nut with a spanner, then gripped the spindle nose, (where the chuck mounts) with my hand and testing the tightness. One thou was removed and the process was repeated until the spindle locked, and couldn't be turned by hand. I then added 0.0005" on the feeler gauges. Sometimes 0.001" to get it to turn with a grip on the spindle nose. Once I had this one dialled in I loosened the nut off again and turned to the other bearing, the process repeated until a fit was found as before.

Once I had the distance for both the front and rear bearings, I tightened both of them up with the feeler gauges inserted with the correct gap, to allow movement of the spindle. The grub screws were nipped up, and turned ever so slightly from the point of them starting to bite, a quarter turn of the grubscrews locked the spindle, it was eventually left at an eightth of a turn. Which still allowed the spindle to be turned by hand with a good grip on the spindle nose.

• 

The spindle is now free to turn and adjusted correctly to run now without any of the knocking noise that I had before.

[Brian WoodParticipant @brianwood45127]

Hello Jon,

I continue to follow this thread of yours with interest. I now have a couple of questions

• Did you correct the chuck error by installing the jaws in the right order?
• These grub screws you refer to with respect to the bearings, you confuse me. Which ones are these please?

If this was my lathe, I would take the job a little further and make packers to the feeler gauge dimensions you have establishes for each bearing, drill holes through each and fit them in the two gaps with the bearing clamp bolts through the holes to keep them in place. That way the bearing shells can close down onto solid material rather than having an air gap as presently.

Maybe I am being ultra picky, but it seems more complete.

Regards Brian

[Jon CameronParticipant @joncameron26580]

Hi Brian not picky at all, that is my intention, (eventually) for the reason you suggest, is that the bolts and bearing clamp can be installed onto something solid. The ML7 uses peelable shims for this, which can be adjusted to by peeling a thou layer off before checking again. Unfortunately peelable shims for the ML4 like the bearings are long since out of production.

The grub screws that I refer to, if you look at the oil pots on top of the headstock, next to each one is a slotted grub screw, these are used for fine adjustment of the bearing. These push down on the top of the bearing, forcing it onto the spindle, again too much force here could crack the casting, so little adjustment and check, then little adjustment and check.

There's a couple of eBay sales, that I've seen in the time I've had this lathe, where the owner has been ham fisted tightening the bearing nuts down, without any packing and the casting goes PING, as the stress is relieved on the top of the casting, across the weakest point, (where the holes drilled for the grubscrews.

I have a friend coming over later today and the spindle is getting pulled out to ensure that it's actually still round, and not oval shaped, though I think it still is going on the resistance of the spindle, as there is no tight spots to be found. There's a few other things that he'll be checking too, so we can try and get this tired lathe into a usable condition.

[Jon CameronParticipant @joncameron26580]

As for the chuck I haven't touched it at the moment, the spindle been the more important part at present, get this right, then look at the chuck, get a 1" bar in there and check how far out it is. Then level the lathe, now I have cutters that work effectively. I was still getting a poor finish on the part, even though they were sharp and had a rounded end. So following some advice looked at my spindle which had a lot of slop in it. Which hopefully will now rectify the poor finish. If it doesn't then at least I can rule out the spindle.

[Brian WoodParticipant @brianwood45127]

Hello Jon,

Thank you for the grub screw information; I recall them now from Dad's lathe. I might be wrong but I thought those were to do with holding the white metal bearing shells in the upper cap half of the bearing and not as you have been using them. I never investigated them though to establish why they were present.

To my mind, local pressure from those would tend to distort the bearing material away from it's support in the cap and wear that part preferentially ahead of the rest of the upper shell. I always adjusted those spindle bearings with the clamp screws, closing down onto a solid section that could be lapped away instead of pealing off shims as even then, shim packs for those bearings seemed hard to come by.

Regards Brian

[HopperParticipant @hopper]

Posted by Brian Wood on 10/10/2017 10:13:55:

…I always adjusted those spindle bearings with the clamp screws, closing down onto a solid section that could be lapped away instead of pealing off shims as even then, shim packs for those bearings seemed hard to come by.

Regards Brian

No need for shim packs. Just buy a packet of mixed sheets of brass shim and cut your own shims of the needed thickness to suit. Easiest way is to cut the shim with scissors then either punch the bolt hole with a wad punch or cut a U shaped notch out of the shim with scissors. I do this on my ML7 rather than pay through the nose for shim packs. If you make a stack that includes a few two thou shims, this allows you fine adjustment. If you want to close the bearing up by one thou, you can take a two thou shim out of one side but not the other. (The purists will arrive at the gate with pitch forks and torches shortly, but it works just fine and is common practice.)

[Jon CameronParticipant @joncameron26580]

Posted by Brian Wood on 10/10/2017 10:13:55:

Hello Jon,

Thank you for the grub screw information; I recall them now from Dad's lathe. I might be wrong but I thought those were to do with holding the white metal bearing shells in the upper cap half of the bearing and not as you have been using them. I never investigated them though to establish why they were present.

To my mind, local pressure from those would tend to distort the bearing material away from it's support in the cap and wear that part preferentially ahead of the rest of the upper shell. I always adjusted those spindle bearings with the clamp screws, closing down onto a solid section that could be lapped away instead of pealing off shims as even then, shim packs for those bearings seemed hard to come by.

Regards Brian

Interesting Brian, though if it were the case that they were to hold the bearings, then surely that would mean they would screw into the bearing shell and lift it, not push it down? Will have a better look today when the spindle gets pulled.

[Jon CameronParticipant @joncameron26580]

Posted by Hopper on 10/10/2017 10:51:20:

Posted by Brian Wood on 10/10/2017 10:13:55:

…I always adjusted those spindle bearings with the clamp screws, closing down onto a solid section that could be lapped away instead of pealing off shims as even then, shim packs for those bearings seemed hard to come by.

Regards Brian

No need for shim packs. Just buy a packet of mixed sheets of brass shim and cut your own shims of the needed thickness to suit. Easiest way is to cut the shim with scissors then either punch the bolt hole with a wad punch or cut a U shaped notch out of the shim with scissors. I do this on my ML7 rather than pay through the nose for shim packs. If you make a stack that includes a few two thou shims, this allows you fine adjustment. If you want to close the bearing up by one thou, you can take a two thou shim out of one side but not the other. (The purists will arrive at the gate with pitch forks and torches shortly, but it works just fine and is common practice.)

Hopper this is much like I want to do, a piece of steel of around 2/3rds the thickness of the gap forming the main spacer, the rest been taken up with brass shim cut and shaped to suit. Though at worst the shims could be unbolted and a set made up from one this then cut to size would suffice for now. Until the shims were made up.

I've had the lathe since May and still not got it 100% yet, as it's only the last 3months that I've looked at getting it sorted. Involves a lot of questions and info been provided by members of this forum and others too.

[Jon CameronParticipant @joncameron26580]

Well I had a friend come around to look over the lathe and check wear.

The bearings in the headstock of mine is simply a bronze split bearing turned OD and ID to fit the spindle and the headstock casting. This is a later modification by a previous owner, as the casting will have had to be bored out to fit this type of bearing. There is a slot along it's length of around 2mm which is lined up with the split of the casting. The bolts tighten down on the casting an thus the bearings and close the bearing around the spindle, the grubscrews used to put pressure on the top of the bearing giving even pressure. The spindle was measured too and was 1thou less than an inch all the way around. Which at least means the spindle isn't bent, or worn oval. Reassembled, the play was then adjusted out. The bearings are worn and will need replacement when funds allow, but are serviceable at the minute.

The gibs have been tightened to take out any play, though new ones could do with making in the future.

The major issue found is the tailstock, the bore is worn, giving 8thou play of movement. Which means that drilling a hole would be a precarious operation, this can be reduced by nipping the spindle lock, but still doesn't irradicate the movement, just lessens it. I've had the fix explained to me, so I'll try it one day with some assistance. The end is bored to take a sleeve, then the sleeve turned to fit the spindle and the new bore in the tailstock.

It's not great but any small holes I'll need to remember to nip the spindle lock on a little to take the play out. Until it's sorted that is. Funds at the minute are limited, so may be some months before I can fix all the issues, but it is now levelled and dailed in as accurately as possible, to within a thou, even on the tailstock.

Brian this was done with a test bar between centers and a dial indicator. The test bar at one point been within 1 micron accuracy, a little more these days after a lot of use and years. After all my frustration trying different methods two adjustments and it was within 1thou. The designer of the tailstock been blasted by my friend for its naff design, and lack of register to bed.

A big Thank You to my friend for taking the time out to come and tune my lathe up and identify what is good and what isnt, and where money needs spending.

[Brian WoodParticipant @brianwood45127]

Hello Jon,

I'm glad to hear you have got things about as good as you might wish for on a worn lathe of this age and had the benefit of some experienced advice.

Thank you for the update on the spindle bearings, those on my Dad's lathe were in white metal and factory new when he bought it—they were still in use when I sold the lathe on roughly 50 years later. Similar design to the bronze bearings you described with a split down one side.

The tailstock soleplate design was an awful thing. Myford did offer an upgrade in the 70's by fitting a tenon across the thing, at your expense of course, I was tempted at the time but never took it up. By then the ML7 had taken over as their lead machine and support for the ML4 began to wane.

I hope you can now begin to enjoy using the lathe, you will make allowances for it's wear and individuality, they were not all bad!

Kind regarfds Brian

Edited By Brian Wood on 11/10/2017 09:08:09

[Jon CameronParticipant @joncameron26580]

Here's a YouTube video I made, this is part one. It shows (I hope) the setup, what has/hasn't been done, and what I intend to do in the near future. Part two will follow probably tommorrow, as internet speed at home is rubbish.

[Jon CameronParticipant @joncameron26580]

Video Part 2

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