questions about setting up my Myford ML4

I recently bought an old myford ML4 lathe that has stood neglected for a few years. My idea was to get it into decent running condition and learn how to use it with a view to perhaps buying a'better' lathe in the future if i manage to master this one. I've done a fair bit of fabrication and metal work in the past but have never used a lathe before in my life, though i do have an idea of the basic principles.

The first problem i found was when i took of the guard on the bull wheel.

i'm half way to solving that problem as i mentioned it elsewhere and Brian Wood has supplied me with a new bullwheel which has now arrived, all i need to do is fit it, i'll need some guidance on how to do that but i believe there's some info on dismantling the headstock elsewhere on the forum so i'll look that up.

some other probably daft questions, the wheel for moving the apron along the bed doesn't seem to work properly, the lttle cog just threads onto the end of the handle spindle,

so when you turn the wheel it just undoes the nut or tightens it until it binds, is there supposed to be some kind of slim locknut or something?

secondly the tool post, the original clamp is still in the bock of rusty bits that came with the lathe, but it has a more modern square tool post about 47mm square with the bottom of the slot for the toll about 10mm from the base, i bought some cheap import 10mm tooling to get started with and found that in this post even 10mm tools are above the centre height by a couple of mm at least. i wondered if one of the mini lathe quick change tool posts you can get on ebay with adjustment on would solve this issue?

Hi,
Have you disengaged the leadscrew nut before trying to use the rack traverse? Does the slike move at all?
I also note the headstock beaings appear to have screwdown greasers fitted. The bearings need oil, not grease. If there is grease in the the lubricators it will need to be stripped and cleaned out.

Robert G8RPI.

The ML4 is a relatively small lathe, so you would have been better to have gone for 8mm tools. NOW he tells me!

is there any chance that you could return the tools in exchange for 8mm?

If not, you need to remove 2 mm from the shank of each tool, by some reasonably accurate means.

In normal times someone in your local M E club would probably have been able to do this for you, but now it is more difficult, but probably not impossible.

Whereaboiuts are you? It may be that someone on here would be prepared to have a go at the job for you.

With response to your query about the handle for traversing the Saddle, yes you need a locknut. Having adjusted the end float to the minimum, consistent with ease of movement, the locknut then locks the handle to shaft in that position. Needless to say it will be BSF or BSW, so you may end up making your own!

If you read the Myford ML1 - 4 pages on Lathes UK, you will learn a great deal about the machine, and it's quirks.

If you can find the Serial Number, Jon Cameron may be able to give some idea of the year of manufacture. (PM him )

I have helped recommission a ML4, but not one with damage such as yours. (Your previous owner looks to have engaged backgear as a means of unscrewing a stuck chuck. You now now know why this not advisable.

That machine did not have Tumbler Reverse, and although it had a complete set of Changewheels, no studs on which to mount them!

The owner was not interested in cutting screw threads, but I cut an extra 20T gear and modified a 60T from a ML7 so that a fine feed could be set up, using the studs that I made. This allowed a fine feed of about 0.004"/rev to obtained.

I would suggest making a Centre Height Gauge, to help you set tools to centre height, to ensure that they cut properly and well.

Since the threads used on the Mandrel changed over the years, it might be worth making up an adaptor from whatever your machine has, to the "standard" 1.25 x 12 tpi. This will allow you to mount the post 1947 Myford thread chucks or their backplates.

I am not an expert on ML4s, (There are others more experienced than I, on here ) by any stretch of the imagination, but if I can help in any way, PM me.

Howard

You can buy 8mm tooling.

You need to look at the dimensions on the toolpost you mention which is the 250-000 I believe. I have the next size one up. The 250-111 on the Myford super 7.

On my machine I am cutting down the toolholders to get the height I need. However the tooling I have are mainly around 14mm. You will have to measure & compare. As for your other questions I cannot help other than to say you may be able to get some drawings showing your part problems.

Steve.

There should be a locknut of some kind to hold the small gear on the shaft, but you can probably get away with a thread locking fluid, at least temporarily.

If you have the original tool clamp, it should be possible to machine the base of your square toolpost to get it down to centre height for the 10mm tools. Best done in a 4 jaw chuck, but can be managed in a 3 jaw. Quite a good project to learn on.

I doubt if a mini lathe toolpost will fit without a modification of some sort, so it is worth seeing what you can do with what you already have.

Hello Andrew,

On the subject of some guidance in helping you fit the new bullwheel to your ML4 [i'm glad to hear it arrived by the way] I wrote a pretty detailed description for Luke Mitchell very recently on this forum. Go back one page, you will find it under Myford ML4 restoration--headstock bearings and spindle removal to save me the effort of repeating it all again here.

Tool size Dad's lathe came with a full set of tooling he ordered to go with it. These were 3/8 inch square shank, the moderm equivalent will of course be 10 mm square. With some bits and pieces of sheet metal packing, he did all his work that way.

The traverse gear and spindle. It is now a long time ago since I examined that sort of detail, but from memory I seem to recall that the gear and shaft were made as one item, the outer handle was fitted and locked onto the external thread. In you case with the gear threaded on, you could try drilling down the joint face and locking them together with a small grub screw.

And YES, throw away the grease cups as Robert Atkinson tells you to do, oil is the proper spindle bearing lubricant, never grease.

I hope that helps

Regards Brian

Edited By Brian Wood on 11/05/2020 09:35:04

Hi Andrew,

I wont go into detail with removing bull gear as already said above if you search out the thread Brian covers that very well, but if you get stuck my machine is currently apart so I can provide pics of assembly if required.

The gear on the apron, it does screw on, behind it is a small 1/4" split washer, before it goes into the apron, if yours keeps unscrewing then firstly turn it around so that the unused section of the gear is facing the lathe bed when installed this will help to lower some backlash on the traverse. Remove the gear and clean down/degrease. put a little threadlock on the thread (just a drop) before screwing the gear home flush with the end of the spindle. On the other end of the apron there should be a washer and a locknut to adjust the tension a then the handle screws on up against the handle to secure the assembly.

I haven't had experience of the quick change toolposts, I use a four way toolpost that came with the lathe, it takes a variety of tools from 1/4" upto 3/8" and all are on centre, when used in conjuction with packing strips or steel, and beer can for fine adjustment, you'll have to finish off the contents first but i'm sure that wont be much hardship.

As Howard says above, Im compiling a list of serial numbers for the lathes, and id be interested if you could provide yours, though looking at just the headstock I am assuming it to be a later one.

Regards

Jon

Edited By Jon Cameron on 11/05/2020 11:07:08

Thanks very much for the input everyone. WRT the lubricators on top of the bearing cases they are two brass pots with push fit tops and a small hole in the bottom, i assumed they were intended to be filled with oil rather than grease, I've not seen anything similar before but they look similar to the ones on this rebuilt lathe

**LINK**

the thread on the apron wheel is 7/16 BSF, i do actually have some BSF nuts having bought this lot at auction last year

**LINK**

I have several lifetime's supply of whitworth and BSF cap screws etc so if anyone ever needs any, let me know. I filed a nut down to half it's original thickness to use as a locknut but with that on as well the gear was too close to the casting of the bed and was binding, but I'll see how i get on with the suggestions here. I was having trouble with the half nuts not engaging as well but I've stripped all that down and cleaned everything and it di manage on pass from right to left before refusing to work at all, taking it apart again one of the pegs that engage the half nuts had sheared off in the brass of the nut, I'd seen a spare on in the box of bits but when i got it out it had suffered a similar fate plus a cack handed attempt to drill out the broken stud. to my surprise i managed to drill out the one that broke on me and re tap it. by luck i had some 3/16 bsf bolts that were just the right length with the heads cut off to make new studs from, they also had longer threads, the original studs only went into the threaded hole half way, which was probably why they were failing. the half nuts seem to be working ok now.

Brian, the gear has indeed arrived, many thanks it's very well made, i will look again at Lukes' thread for the details of stripping the headstock down.

Jon, I'll have a look for the serial number and let you know what it is, i think you're correct that this is one of the later ML4s

I've done a bit more at this, i followed brian wood's comprehensive instructions on another thread for dismantling the headstock. all came apart no problem, the gear on the end was only a push fit on the shaft some came off easily, the grub screw thread is still good. the threaded collar on the end was very tight an now i've got it off there is some damage / bruising to the threads.

I've found that the new bull gear is very tight on spindle shaft, and i'm wondering whatis the best thing to do here, the old gear was also abit tighter on the end of the spindle nearer the threaded collar, but it di just about slide down and then run freely when it got to it's correct position, the new gear is slightly tighter though, it seems to be near an interference fit on the shaft and i don't want to force it on obviously.

Hello Andrew,

If you have some Scotchbrite pad you could ease the bore of the bullwheel with it, being careful to avoid bell mouthing it when you do so. It was made to a nominal 1 inch bore diameter but it could be a few tenths less which would make it tight.

Alternatively, try warming it with a hair dryer before you fit it

Kind regards Brian

cheers Brian, warm it with the hair dryer, why didn't i think of that?

what thread is on the gear end of the spindle for the locking ring? it needs cleaning up a bit ideally, the ring goes tight on the thread before it gets nipped up.

Sorry Andrew, I really don't know; I have no longer got my Dad's old ML4 to measure.

If you have thread gauges it will not be difficult to check. One thing I can be sure of, it will not be metric!

Kind regards Brian

No worries, i've ordered a thread gauge off ebay, i got a load of old oddball taps and dies in with the job lots i bought from that auction a linked to above, so i could possibly have the right one, failing that i've got some tiny needle files that might be suitable for getting the thread grooves back in line where they're distorted. i had a bit of a play with it last night and i've got the collar going on freely about 2/3 of the way, with a bit of patience i'll get it sorted i think

cheers

andrew

The thread form is pretty certain to be Whitworth, the thread gauges will tell you what pitch.

I would suggest buying a thread file. This will allow you to clean up the threads to the correct form, and pitch, both Internal and External, and so will be safer than using a swiss file.

Howard.

thanks for the advice Howard, i was thinking it would be BSW, i'm ahead of the game as i ordered a set of thread files at the same time

**LINK**

this is turning into an a expensive hobby

Hello Andrew,

It might just be a little cheaper than golf as a hobby, but once the bug has bitten, the interest expands along with the expense!

I would warrant it more rewarding in the long run though.

Regards Brian

Hi Andrew,

The thread on the change gear side to take up end float on the spindle, is that correct????

32tpi rings a bell, its published on the internet somewhere, let me have a look, failing that I can measure it with my thread gauge for you tonight.

Jon

Edit yes it is 32TPI, I would not however run a die down it as the lock nut and spindle thread need to be quite a close fit. So as Howard suggests take a file or even some fine emery paper (1000grit) backed onto a file to clean up any burs. I will be fitting a brass plug under my screw once its back together to prevent the issue you have, (mine is tight but it will still go but I don't want it any worse.

Edited By Jon Cameron on 28/05/2020 10:01:49

I've now got the spindle back together with the new gear in place and it all seems to run ok. i cleaned up the thread with some emery paper on the file as Jon suggested, the thread files have arrived but only go up to 26tpi so were only of ornamental value for this job.

next job is to get the spindle converted as per Brian's suggestion of putting a collar on to take the ML7 fitting chuck that i have to replace the worn out 3" chuck that came with the machine. I've had one abortive attempt to bore a suitable piece of bar out but the chuck is so worn that it's difficult to get it to hold the stock true in order to bore a parallel hole.

Hello Andrew,

When you come to fit your new chuck, and just out of interest, try applying David Bennett's recently reported findings on the actual value of the horizontal register.

As long as the vertical register is true and the nose thread reasonably sound, he and others have found that this combination works perfectly satisfactorily.

If it 'offends' you to ignore the horizontal register, at least the new chuck will hold things satisfactorily for you to make a collar as I described earlier. When I did the modification, I recall using a piece of old water pipe as stock material rather than making it from solid

Kind regards Brian

When helping a friend to get his ML4 running again, to ease the job of fitting a 4 jaw chuck, I made up an adaptor with an internal 7/8 BSW (7/8 x 9 tpi ) thread and an external 1.25 x 12 tpi, thread, with 1.25" register, to screw onto the Mandrel.

I milled two flats, and made a suitable spanner, so that it could be removed when not needed.

In this way he can fit "modern" Myford fitting chucks and accessories to his machine..

Howard