Myford ML4 ?

I decided to run a concentricity check on the lathe before I go any further. The face plate was on the spindle, so with the aid of magnetic base and dial gauge I rn a check on the turned outer edge and was a bit dismayed to find it was running out by around 0.005". I then ran a nother check on the face plate machined face near the outer edge and that too was around .005. I removed the faceplate and cleaned the mating surfaces on both rear of faceplate and the spindle nose with similar results.

I then removed the face plate and checked the spindle nose and it is within 0.0005".

I probably have a test bar that I can try between centres, but at the moment I am reasonable happy with the headstock.

Question is this, do face plates suffer from that kind of run-out generally ,or is my faceplate possibly from a different lathe and should it have been faced up on my lathe before use ?

Mike.

I should have added that I checked the spindle nose in both planes.ie edge and face. I found that I could get around 0.002" fore and aft movement by pressing on the pinion end of the spindle.

Mike,

Hello Mike,

​That is rather more than you should have. There will be a screwed collar on the spindle just inboard of the 25T gear; that is what is used to set spindle end float. It should have a grip screw nipping the screw thread below via a slug of copper shim to prevent crushing the threads, they are quite fine pitch.

Take out the slack until there is just discernible resistance to rotational movement of the spindle. The thrust bearing is a plain flat contact open ball race bearing on two hardened washers just behind the rear of the chuck location register and buried inside the bearing housing .

Regards Brian

Hi Brian,

Adjusted the collar and now no end float.

However, I am now wondering if the headstock spindle has a very slight bend in it.

I will not know for sure until I strip the headstock and check the spindle on V blocks. I tried a test bar in the headstock morse taper (no. 2) and at a distance of around four inches from the spindle front shoulder, I get around 0.005" out of centre.

Mike.

note: check endfloat when at operating temperature.

Hello Mike,

​That is not a definitive test for the running truth of a spindle. It is much more likely to be a tiny burr raised in the taper, or even a small particle of dirt. Your earlier test of the chuck mounting register didn't show more than tenths.

Try cleaning it out, feel inside with your little finger, spindle rotating slowly, and make sure the 2 MT mail part on the test bar actually seats in the socket.

On my father's lathe he must have caught it at some time with a boring bar. I cleared that with a surplus 2 MT drill shank and the merest trace of fine valve grinding paste. The lathe was run slowly and I held the tool by hand. After thorough cleaning, the error was about 1/2 thou at 6 inches. It had been worse than the figure you report. Of damage to the socket there appeared to be none and the tool was still perfectly satisfactory afterwards.

I also endorse what Bazyle says about operating temperatures and be prepared to ease the setting you have achieved if the slightest tightness shows up. The best test is to feel the bearing housings with your finger tips

Regards Brian

Hi Brian and Bayzle, I understand the end float adjustment and hit this problem with my first Drummond, way back when and also have a very similar adjustment on my Boxford. You soon know if it is too tight !!

I ran another test after cleaning the taper with a no. 2 morse taper reamer by carefully rotating it by hand with no pressure on the oiled reamer and now I get 0.002 around 4" from the spindle nose, so looks like I am gettting there at last. I will still check the spindle for truth, once it has been removed from the headstock.

Any tips on removing the spindle from headstock ? I take it that there are two allen keys to rmove and the endfloat adjuster and pinion and to catch the thrust bearing balls in a box !!

Thanks for all advice so far.
MIke.

Hello Mike,

The very fact that you have improved the apparent run out error with your reamer gives much more support to the cause coming from some 2 MT socket trouble. There must be a small bruise in it somewhere.

It is a rather long time ago now since I removed the spindle on my father's old lathe and that was to change the belt as far as I remember. I don't recall allen keys but you may have to draw off the 25 T pinion, it is a very snug fit on the plain turned diameter on the end of the spindle. Watch out for the copper shim under the grip screw for the end float ring. I think that the balls are captive in the thrust bearing but be prepared. It all has to come out over the lathe bed of course.

Refitting the 25 T gear and then matching the two halves of the 2BA locking screw can take time.

Regards Brian

Thanks Brian, all good info. What might simplify the gear refitting, so that the 2BA screw would locate easier might be to insert a rod into the screw hole to act as a guide. The rod would need to be fraction under the root size of the 2BA screw. (I always look for an easy way out !!)

Might not work ,but worth a try, especially if the gear is a very tight fit.

Mike.

Hello Mike,

​I have seen that dodge being recommended on another ML4 question or thread on this forum, so I imagine it makes the job a whole lot easier, one maybe worth remembering for other similar alignment issues as well.

When you come to putting the gear back on, without telling you how to suck eggs, a tap on the end with a nylon hammer will ensure it is fully seated as well.

Regards Brian

.

Hi Brian,

I used to use a similar dodge for lining up large 4 litre car engines with the gearboxes. A couple of studs around 4" or 5" long with a tapped end to match the threads in the rear of the engine block and then these guided the engine onto the gearbox (or vice versa if you were replacing the box) and made life a lot easier.

I spent a small amount of time cleaning the headstock spindle morse taper bore today and now just have 0.001" run out measured at same distance as before. I have an mini inspection camera which I can use to check the bore for discrepancies. I could feel a slight scratch and this could well give an error. I also found that it helps to seat the morse taper centre with a copper mallet.

Most of today was spent repairing the car, as I backed into a 12" section RSG at the local scrapyard yesterday and dented and punctured the rear valance. Managed to get out the dents with a hot air gun and then stitch welded the plastic back up again with a 200 watt soldering iron and now got the repair in primer. Wife not too happy as it was her car !!

Oh well ,made a break from Myfords etc.

Mike.

Edited By sparky mike on 01/09/2016 17:36:14

Hello Mike,

​A rather similar trick to using a podger bar to line up bolting holes on steelwork, and yes, I have united gearboxes and engine blocks together in the same way with long guide bolts. It does make getting the dowels to fit first time. At least you are definitely winning now, it should get down to tenths in the end.

Sorry to hear of the prang at the scrapyard, I can see an expensive lunch looming.

My joy today was a return visit to the dentist to have confirmation of a dry socket developing at the base of a rather tough extraction from 10 days ago. It needs a course of antibiotics now to clobber it.

These come with a booze embargo just to add to the joy

Regards Brian

Hi Brian,

Stripped the headstock and no drama at all. The thrust bearings all stayed in their cage and the end pinion was a nice fit and removed easly. I have now checked the truth of the spindle and on V blocks positioned where the bearing run, the shaft clocked up spot on !! Just the allen screws in pulley wheel and bull gear to remove.

I took the shaft to the other lathe and selected a fast speed and cleaned up the morse taper with wet and dry 500 grit . Now stripped for painting.

I am looking for one Partridge flip top oiler for the leadscrew, but not sure of the thread. (2BA ?)

I did notice that at some time the heasdstock has been modified (by Myfords ?) and the left hand back gear journal support has been cut off. This is not needed as the back gear is on a short shaft on the right side of the headstock..

Headstock has same stamped number as pinion and lathe ,so perhaps it was Myford's who were using up old stock.?

Mike.

Mike.

Hello Mike,

​Good news with the spindle, I didn't think it would be bent.

I can't help you with the oiler I'm afraid. The back gear cluster is on an eccentric, mounted off the short shaft so that it can be swung into position. Make sure everything has come to rest before using it, I chipped two bull wheel teeth through over eager action.

Regards

Brian

Now have the bed stripped and with the aid of a long straight file, I have leveled off all the small pads where the rack sits.

It seems that Myford must have missed this operation as most of the pads were just rough uneven castings. (Friday afternoon at Myfords job ?) One of the pads was nearly 1/8" too high, so this must have been the main reason for all the small washers that were behind the rack.

I now have the job of painting the bed and filling the imperfections of which there were many. Myford did not seem too bothered about fetteling the bare castings in those days. While stripping the paint I discovered the words "Made In England" under the Myford letters. These were hidden under many coats of paint.!!

I found a repair of the apron. The inner V slide had broken off at some time and had been subject to a brazed repair. Looks to be a good strong job, so I am not too worried. The outer slide is bolted on with recessed allen screws, so that may also be a repair dodge, but looks to have been done by a decent engineer.

Not sure what an original part should look like.

I will post a photo later.

Mike.

Mike.

Mike, just realised you are in a perfect position to take a few good photos of your saddle and cross slide components to show Sean on the ML3 thread what he needs. Particularly to compare to the gumtree advert he linked to.

Bazyle,


​What a good idea. From the effort that Georgineer put into the ML3 posting it would seem that there were probably identical parts used over the range. Manufacturer will usually try and use common parts where they can be to avoid all the stocking problems of individual parts.

Mike

Good progress by the sound of it. A brazed repair is of course quite satisfactory and for the kind of disaster that must have fallen upon this machine. an inserted piece, made to match the shape and form of the surrounding dovetail would then have been used as the reference face to repair the other side with a bolted on fitting. It would not surprise me if you find it has also been dowelled into position.

It would not have been a cheap repair and certainly not commercially viable, so clearly whoever did it had access to a well equipped workshop and knew what they were doing. Others would have bought spares from Myford, but they might have been unavailable in the wartime years, perhaps that was the deciding factor at the time.

I would though check out the alignment to the spindle to ensure it is actually correct, there may be errors arising purely from the additive nature of the method adopted.

Regards

Brian.

Edited By Brian Wood on 04/09/2016 10:25:00

Hi Brian,

I will go and take some photos shortly of the cross slide etc. All paint is now stripped off but it is all in one piece.

I had to make a new threaded pin that is one of the two pins on the half nuts that engage with the slots in the handle. It was far too short and only just catching. When I post the photos, bear in mind that I don't know what is original and what is not.

eg. There is an extra low gear on the saddle for end to end traverse and have not seen this yet on other ML 1/2/3/4 lathes but perhaps this was "borrowed" from a later machine.

One thing I am stuck for at the moment is this.

How do you remove the pin at the front of the tail stock in order to remove the shaft. At first I had thought it was a slotted screw, but is is slightly loose but does not want to come out. Do I have to close the slotted part in order to withdraw it or what ?

Mike.

I have now added an album headed "ML4 parts."

The screw/plug ? whatever can just be seen in the last photo. IMG 5972.

Mike.

Hello Mike,

​I misread the dovetail repair on the apron clasp nut guide for a repair of the dovetail guide on the saddle for the cross slide, so my remarks with regard to alignment to spindle would have made no sense at all for the repair that has been carried out. It looks a neat and workmanlike job to me.

Removing the tailstock anti- rotation pin can only be done when you have drawn the tailstock barrel free of it back out of the rear of the tailstock. The pin itself is threaded and has a key on the internal end which engages with the slot down the barrel. It should be slightly slack, the adjustment can only be 1/2 pitch of the thread on it, that may be too much and will prevent easy entry into the slot. I think the screwdriver slot on the end you can see mirrors the key alignment inside

To withdraw the tailstock barrel means removing the two half plates that secure the operating collar in contact with the body of the tailstock and then sliding it backwards. From memory, they are held in position with one screw each 

Regards

Brian

Edited By Brian Wood on 04/09/2016 18:48:51

Edited By Brian Wood on 04/09/2016 18:49:35