Myford ML10 dog clutch dimensions

Could someone who has an ML10 please tell me what is the outside diameter of the leadscrew dog clutch, ie the sliding cylinder on the leadscrew.

I want to make my own copy of the clutch to fit on my ML7 so the graduated leadscrew handwheel can be used without having to remove change gears etc. I got so used to it on the old Drummond M-type that I really miss having it.

There is one amateur drawing floating around on the net that puts the OD at 25mm but that seems a bit small to me, so would like to confirm what diameter the factory original was on the ML10. The one on the old Drummond is more like 1-1/2" diameter but they were a much more solid machine than the ML7 so not sure which way to go.

Thanks

Hopper

My ML10 is an imperial model and the OD is 1"

Thanks for that. I will make life easy for myself and make it 1" like the original.

Another question: Is there an Oilite-type sintered bronze bushing in the right-hand end of the dog clutch where the leadscrew fits in? I think the end of it should be visible if it's there.

The internet drawing I found by Nico DeFrank shows no bushing, so the steel leadscrew runs in the steel dog clutch body when disengaged. But an ancient post on another forum mentions in passing an Oilite bushing for the leadscrew to revolve in on the original Myford dog clutch. Which seems like a good idea but would like to confirm the original had one. I know my old Drummond dog clutch runs steel-on-steel so probably not necessary but maybe nice to have?

No oilite bush in my dog clutch, cut the leadscrew where the groove is and clean ends, insert the sleeve the right way round and carry on. Worth buying the graduated drum for the right hand end. it will be scaled for metric or Imperial depending on the lathe..

Mine is metric and has 3mm engraved on it. The drum is fixed to the lead screw. To use it for setting length I bring the tool to the job and then set the top slide to give me a '0' setting on the drum.

Thanks Clive. That will make life easier. I had concerns about the bush moving and the dog slots no longer lining up etc. KISS principle sounds good to me. Steel-on-steel should be ok under such low stress, low rev usage.

I am making mine to fit my ML7 so no factory groove in the leadscrew. I will work out the cut position from the illustration in the ML10 manual I have. I have a graduated handwheel in place already. That is what has prompted me to make the matching dog clutch instead of removing the change gears every time I want to use the handwheel. It is something I got very used to on my old Drummond M-Type and wouldn't be without out it if I have a choice.

It is particularly handy for milling with the vertical slide where I use the leadscrew handwheel for X axis movement and measurement. Also for general turning for roughing feed but also so I can leave the topslide canted at 14 degrees so it clears the tailstock and provides 1 thou of infeed for every 4 thou of movement on the topslide dial. Then just use the main leadscrew handwheel for measuring and turning up to shoulders etc.

I will probably go one step further than the ML10 though, due to the ML7's longer leadscrew, and put a support bracket with bronze bushing on the leadscrew directly to the right of the dog clutch, just to take the weight of the leadscrew off the dog clutch. May be overkill but I don't think it will hurt to have the leadscrew firmly supported. The Drummond has a casting supporting the OD of the dog clutch to achieve the same thing, but no room for it on the ML7 so the extra bracket will do the same thing.

It will be a couple of weeks before I can get back out in the workshop as I am convalescing from minor foot surgery but will report back on how it goes when I get there.

Edited By Hopper on 13/06/2022 02:02:20

Another question has popped up: On the brass (presumably?) block that attaches to the operating lever and engages in the groove on the dog clutch body, is the surface of that block curved to match the diameter of the groove in the dog clutch body, or is it just a flat block that sticks into the groove as best it can?

It is curved as you suggest.

Thanks EB. On second thoughts, I am guessing it must be a slight curve rather than a close fit to the radius of the dog clutch body, because the block actually travels in an arc as the lever pivots, so a tight fitting curved block would bind. That explains why in the one pic I have of a dis-assembled unit, the block looks to have a slight curve to it but not a tight fitting radius. I reckon I can fake something up that will work on that principle.

Here is the one pic I could find of a dis-assembled dog clutch. The slider block does appear to have a slight curve on it. But very hard to tell from the pic. So good to confirm that. Thanks.