I have an Alan Timmins dividing head which came from Blackgates as it has the same spindle and thread as the Myford and chucks etc can be used on it.

David

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There is a great deal of merit in that approach

Generations of watch and clock makers can’t all be wrong

MichaelG.

I have a Myford Dividing Head which can be mounted to divide the lathe spindle or on a raising block or vertical slide. I also have a George Thomas versatile dividing head which is cross slide mountable at centre hight and a Headstock (GHT Radford design) dividing head that attaches to the bull wheel. The last unit is stepper converted and is very usefull for clock wheels along with it's electronics but I also have an overhead drive which drives a spindle mounted on the vertical slide. The GHT cross slide unit is also mountable on my mill using adaptor plates and has it's own tailstock. With the micrometer adjust on the GHT and the GHT/Radford any angle can be set. I do have a BS dividing head but I have never used it.

If you are cutting clock wheels (high speed cutter) I suggest dividing the lathe spindle and using an auxilliary spindle for the cutter, if it's spur gears in steel for traction engines (low speed cutter) then you need something on the crosslide/ virtical slide or on the mill.

regards Martin

It was and they were very good.

regards Martin

It is not that it couldn't work but the thing weighs 40lb. I don't recommend buying a 7.5 ton truck for nipping down to the corner shop.

The Myford Rotary Table, looks to be a rebadged Vertex HV6 . In which case it will have a 4 inch centre height, and will require a raising block to raise it to the centre height of the 254.,Nominally 3/4" by the sound of it.

But, is the 4 3/4" the centre height over the Bed or the Cross Slide?

Presumably, you are thinking in terms of mounting a gear cutter on an arbor, either in a chuck, or on a Morse taper, so that the Cross Slide sets Depth of Cut, and the Saddle is moved along the bed to provide the feed, while the Dividing Head / Rotary Table takes care of the dividing?

Mounting the DH or RT on the Saddle may bring the centre height above that of the Lathe, unless the raising block can be attached to the Cross Slide by some means, whilst resting on the lathe bed.

Howard

Edited By Howard Lewis on 05/03/2021 17:14:28

Apart from high speed cutting of clock wheels,I never did see any point in using a lathe spindle as the dividing element and cutting with another attachment, A lathe spindle is designed to be used for driving work and cutters so why waste the spindle,far better to have a separate index device,I have a Myford dividing head,and found it useful,the only snag as I see it is that the main workholding device is the chuck which being threaded could under intermittent cuts become loose. though this can be overcome by using the 2MT spindle socket,and make up a mandrel to suit the socket and secure the gear to be cut,support the outer end of the mandrel with the centre. There are a lot of illustrations in tearly technical books of workpieces secured via the M/Taper. the mandrel should be secured in the taper by a stud and nut, and idealy the gear held firm by a nut and a keyway in the gear locating in a key way in the mandrel. The book "a practical treatice on milling "by Brown and Sharpe who were one of the most famous machine tool makers in years gone by is a good read I got mine via ABE books for a few pounds those published in the 1930s are very good though it shows industrial use not model work,though there is a good chapter on gear cutting.

As you say cutting clock wheels is a very good reason to divide the headstock indeed any second operation where it is useful to be able to do the machining at the same setting and hence concentricity. Cutting spines, drilling on a pitch circle for lantern pinions, cutting squares on the ends of shafts, planing straight knurlings, engraving chapter rings and micrometer dials and stamping numbers the list goes on. Possibly the only reason for a dividing head on the crosslide/vertical slide is cutting spur gears which are better done on the vertical mill in any case.

regrds Martin

16DP x 100 teeth is over 7 inches outside diameter.

Only 6 3/8” by my calculator.🙂

a lot of fine passes.

DP16 gears would only need one cut/tooth I would have thought (at least for cast iron).

Thats true, I've done a 16dp 90 tooth iron gear on a BS0 with the Centec, but had to use the horizontal arbor in the vertical head to get the height. Even ignoring work holding the blank and cutter already eat up a bit more than 4" of daylight between centres.

You occasionally see a Jones and Shipman 1mt divider on ebay, they don't go for much and look like the Alan Timmins head except the dividing plate is direct mounted to the shaft and would need modding to take advantage of the worm wheel gearing. It should fit the rear toolpost slot.