Myford ML1 ? or 2 ?

Thanks Brian - very useful information there - I will count the teeth and post the results on here. I think I have a full set of gears about 10 in total.

So put it simply - the gears used in between the spindle gear and the lead screw gear have no influence of the pitch of the thread, there only influence will be the speed in which they turn the lead screw

All I need to know is the spindle gear and the lead screw gear ?

The other lathe in the background is my Harrison 140, I also have an Alfred Herbert vertical mill.

No.

The intermediate gears have no effect at all on the pitch or shaft speed, any more than a fabric belt linking two pulleys does. They merely transit the drive between the spindle gear and whatever gear is fitted to the leadscrew. An odd number of linking gears will preserve the rotation direction, that is the only effect.

On a belt drive the receiving shaft rotation direction is changed by twisting the belt through a half turn between the two pulleys, the pulleys will still have the same speed relationship one to the other.

Brian

Edited By Brian Wood on 21/12/2021 16:47:58

The gear shown in your pictures meshing with the gear on the mandrel is where the back Gear and shaft should be.

Study the Lathes UK pages that cover the Myford ML1, 2, 3, and 4. You will learn a lot from them..

The purpose of the Back Gear is to slow the speed of the mandrel.

It does this by moving into mesh with the gear at the rear of the mandrel.  The drive passes through the larger gear along the shaft to a smaller gear which meshes, when engaged with the gear on the Mandrel, just behind the bearing behind the chuck.

The Back Gear is engaged by a lever which rotates an eccentric bush causing the shaft to move so that the gears mesh with those on the Mandrel. In one of the grooves of the belt pulley there is a grubscrew, which under NON Back Gear use, locks the Pulley to the mandrel. When Back Gear is engaged, this grubscrew must be slackened, (preferably removed and put in a safe place until required again )

Failure to release / remove the grubscrew will lock everything, since you are effectively trying to drive through two different ratios. And that can't happen!.

Engaging Back Gear will reduce the Mandrel speed to about a sixth of the normal value.

Normally, the Changewheels will range from 20T to 65T, incrementing by 5T.

Having three 20T , and an extra 60T will enable you to set up a train giving a fine feed. 20: 60 / 2 : 65/20 : 60.

This should give a feed rate of 0.0043" per revolution of the chuck.

For screwcutting, if and when you choose to do that, you will have to set up a gear train to give the correct ratio between the Leadscrew and Mandrel to give the pitch that you want.

Brian Wood will the man to advise on how to go about this. (He has written a book about it! )

The pre Series 7 MLs had a few peculiarities, by more modern standards..

Because there was no Idler in the Apron between the Handwheel and the Pinion engaging with the Rack. Turning the Handwheel clockwise moves the Saddle TOWARDS the chuck, not away from it.

Also, to provide a power feed TOWARDS the chuck, two stages of reduction, or one and an Idler, are required (The Leadscxrew is 8 tpi, but Right Hand, rather than the Left Hand to which we are most accustomed. Hence the need for an idler, second Compound gear to ensure that the Leadscrew rotates in the correct direction.

Gears are compounded by linking them with 3/32" pins, in the same way that the Mandrel drives the first gear, and the t final gear drives the leadscrew.

The Cross Slide and Top Slide Leadscrews are 12 tpi, so each of the 80 divisions on the Handwheels are not exactly 0.001" (0.0010416667" according to my calculator ).

In M E W 310 there was an article on recommissioning a Myford ML4 which you may find helpful.

Howard

Edited By Howard Lewis on 22/12/2021 17:19:45

If extra changewheels cannot be obtained from somewhere for the ML 1,2, 3, or 4, gears for the 7 Series will fit. They are the same bore and width, but will need to be drilled to take the 3/32 driving pin

The technique means modifying one of the existing gears, by drilling the hole right through so that it can be used as jig to drill a hole into the "new" gears, when existing and "new" gears are mounted on one of the studs..

(The article in MEW 310 describes this method )

7 Series wheels are driven and compounded by a key and keyway, rather than the driving pins used on your machine...

Howard

Check out thread Myford Id

restored ml1 last year

cheers David