A photo would be much quicker…

Lathes UK website is a mine of information.

Briefly;

ML1 and 2

3.125" Centre height. ML1 is 15" Centres, ML2 is 24" centres.

ML3 and 4 3.5" centre height, ML3 is 15" centres, ML4 is 24" centres.

Not all have tumbler reverse (this was an optional extra)

Mandrel thread was originally 7/8 x 9 tpi (Standard 7/8 BSW), this changed to 7/8 x 12 tpi, and the very last ones , I believe, had 1.25 x 12 tpi, but lacked the 1.250 register which became the standard when the ML7 was introduced in 1947.

Secondhand machines may not adhere rigidly to spec, possibly having been modified since being built. So you could have a bed with an early serial number, but a much later, or even different, Mandrel fitted.

Ex factory, Mandrel and Tailstock were 1 MT.It is possible that some owners may have modified to 2 MT

Threads will be BSW and BSF. Gib strips may be BA.

The Leadscrew should be 8 tpi, but Cross and Top Slde leadscrew were 12 tpi, the dial having 80 divisions, so that each increment is slightly more than a thou.

Changewheels are 20 DP, 14.5 degrees pressure angle, but are driven / compounded by 3/32" pins in holes drilled partway through . Gears from the later 7 Series will fit, but will need the 3.32 hole to be drilled. (this will probably mean drilling through one of the existing changewheels to act as a drill jig. If you do this ensure that the hole is well away from the keyway.

The Tailstock cross travel adjustment is not of the best design, but was improved. It is "liveable" with care.

HTH

Howard

Robert,

Nice to have clarification from the horse's mouth, so to speak.

My greatest experience is only of trying to help someone who thought that he had a ML2 but I found the hard way that it was a ML4. It was awkward, since the centre height gauge had been made for 3 1/8 and having travelled 140 miles found that it was 3 1/2!.

We never got to the point of examining the Headstock bearings, so your contribution will be an extra aid in determining which model.

All extra knowledge.

Howard

Robert F 4:

To quote a post I made in an earlier thread, quotiing a post I had made in an even earlier thread:

" "Some simple measurements and observations can identify which of the different models ML1 to ML4 one is faced with:

ML1 & 2: 3 1/8" centre height, 15" between centres, 3 1/2" cross slide travel.

ML3 & 4: 3 1/2" centre height, 24" between centres, 4 1/2" cross slide travel.

ML1 & 3 ('Standard' models): Spindle bearings direct in headstock.

ML2 & 4 ('Superior' models): Bronze spindle bearings, shrouded ball thrust race.

My understanding from lathes.co.uk is that the cast-in headstock was abandoned in 1937, so from then until the ML1 and ML3 went out of production in 1941, all models had the removable headstock."

The ML4 used three different spindle nose threads, Earlier ones 7/8" x 9tpi or 7/8" x 12 tpi. Later ones used 1 1/8" x 12 tpi, the same as the ML7 but with a smaller register diameter. I don't know what threads were used on the ML 1,2 &3 but they would almost certainly have been the same."

Since your lathe has a serial number, I would guess it's one of the later ones, and the most likely model is the ML4 simply because they were made in larger numbers.

All my information has come from Myford documents or from lathes.co.uk. Soem time ago I wrote to Tony at lathes.co.uk suggesting that it would be helpful if he put this information as a table in his website, but it hasn't happened.

Incidentally, Robert, if you do searches on this forum for "ML1" through to "ML4" you will discover that there is a wealth of valuable information and experience concerning that family of lathes.

George B.