Dividing Head, what make is it?

Hi gang, I bought this dividing head and centre recently. Can any one tell me the make and is it all there? also is it possible to find instructions or any other information? thank you in advance. MD

Edited By JasonB on 06/11/2022 13:09:09

Sorry, no

But it’s a very neat arrangement, and it will be interesting if someone can identify it.

MichaelG.

I would be inclined to call it an indexing head rather than a dividing head.

You can use it in two modes: with the worm engaged and with the worm disengaged.

A normal dividing head would have the dividing plate and sector arms on the end of the worm, where the handwheel currently resides.

Hence with the worm engaged it is more use for milling circular features on parts held in the chuck.

With the worm disengaged, you pick a hole circle that is a multiple of the the number of divisions you want, set the locking pin to the radius of that circle and drop it into the hole to index. You can turn it by hand from hole to hole or use the worm and handwheel but the latter will be quite slow. To ensure you do not drop into a hole you do not want, put insulation tape over the surplus ones in the circle or bung them up with a foam plug.

Have a look at the George Thomas one at Hemingway kits to see the principle of operation (his only has one hole circle on the end of the spindle, whereas your own has multiple hole circles).

I have one of those, it's reputed to be a Jones & Shipman. Yours looks to be complete.

Pretty much self-explanatory in use. You need to keep a careful count of the holes.

I treated mine to an 80mm chuck. It's very handy for cutting small tooth count gears and milling slots in shafts.

.

This … which is configured differently … appears to be a similar basic unit

**LINK**

https://www.ebay.co.uk/itm/274036592228

MichaelG.

Edited By Michael Gilligan on 06/11/2022 21:48:58

Whew! I purchased a full 4 plate Myford unit many years ago for a lot less dosh and it came with the previous owners home made extra disc in brass, 28 holes, 1 ring. Wonder if there is a clock making connection? Thinking 28 days, February.

John

Looks like a very nice little unit. Could easily be set up with a set of index plates off one of the Far Eastern dividing heads or rotary tables with the same number of teeth on the worm wheel. They are reasonably priced and sold separate to the dividing heads/RTs.

I wonder if it could be used as is by turning the worm handle X number of full turns then advancing by the appropriate number of holes on the appropriate circle to get the desired division? Bit of simple math would work it out.

Is this a necessity or just a nice thing to have? The hole circles on dividing heads generally contain prime numbers which are unrelated to any specific worm ratio.

No idea about the math. That's way above my abilities at this time of night.

But looking at the indexing charts for various worm wheel sizes eg 30, 40, 60 and 90 teeth shows there is a large variety of hole circles used and they are not universal across all worm wheel sizes. Some are common, some are not. And some are not prime numbers. So if I were buying a set of index plates I would look for one matched to the wormwheel tooth count I had to make sure the hole circles I got were relevant and useable. The wormwheel in the pic looks like a 60T so should be easy enough to match.

(Ref: Charts in back of Harold Hall's book Dividing. I suppose if you pored over it you could work out exactly what circles you needed and what would work and what would not. It's a good book to have anyway if you are getting into dividing.)

Edited By Hopper on 07/11/2022 09:01:25