Identifying a vintage lathe

Hi Haydn, you need to see if you can get a couple of 20 tooth gears and a 73t one. but even getting one 20t will help.

Regards Nick.

Thanks, I think I understand it now, I’m on the case !

have a look at the Drummond group on io.groups - there used to be a document on there called. I think allsets which listed all of the different sets of change gears that Drummond supplied over the life of the lathes. I don't think it will matter which set you use - I would choose the one where you need the fewest extra gears,

There is a set of 3D printable drummond gears on Thingyverse, but I have not had success printing some of the sizes,

I added extra fine feed to my Drummond M Type by using cheap as chips toothed belts and toothed pulley off t'internet. XL series belts and pulleys from memory. Much cheaper than gears. I bored them and fitted bronze bushings and made my own spindles etc for them to mount on.

Standard Drummond gear set is 20 to 70 by fives plus a 38 from memory.  But the groups.io Drumondlathe group has the exact listings.

Edited By Hopper on 29/09/2022 10:39:11

Edited By Hopper on 29/09/2022 10:41:39

A full set is

20
20
30
30
35
38
40
45
46
50
55
60
65
73

I've done my babbit pour so will write it up in the next day or two

Hi Hopper, that is a really clever idea, I like it. One could of course use any gears that would fit and mesh with each other, and if the bores could be adapted, and if the two driving holes could be put in, to match the Drummond gears, you could mix gears on the same pin providing they clear on their sides so they miss other overlapping gears, but the gears you choose would need to be at least as robust as the Drummond ones are. According to my M type genuine Drummond Bros. ltd. booklet, the Chage Wheels supplied as standard are; 2 x 20, 2 x 30, and one each of 35, 38, 40, 45, 46, 50, 55, 60, 65 and 73, of which I have all of those with my Myford M type.

Regards Nick.

P.S. Ady1 & I agree on one thing at least.

Edited By Nicholas Farr on 29/09/2022 11:16:33

I think you have to be a bit careful though. Gears of like DP will mesh, but not very well if the pressure-angles differ.

Hi Nigel, I think you may have misinterpreted what I was saying. I don't propose meshing gears of different DP or different PA, what I mean is to gang two gears on one pin in a chain of gears, where each gear is meshing with the same DP and PA as their own type. OK, it's a bit messy, but it could get one out of a muddle when gears of the same DP/PA are not available, but it will need the ability for the two different gears being locked together that are on the same pin.

Regards Nick.

Edited By Nicholas Farr on 30/09/2022 07:24:16

Oh, that would be fine, Nicholas!

It was something I found when I was looking at enhancing the range of change-wheels on my EW lathe. They run from 25 to 65 teeth by 5s, if I remember correctly, and the machine won't accommodate more than a two-step compound train. I'd considered filling in some of the gaps, e.g. with a 32 or 63T wheel.

The EW uses similarly to the Drummond, a small pin to connect gears side by side.