As it seems you have a good height from spindle to table I believe a BS0 Dividing head will suit your machine and provide a good range of divisions and working angles.

Emgee

Our light vertical at the museum has lost about 1" of Z height since I converted it to R8 from MT2, but the 6" vertical/horizontal rotary table fits on it no bother. With a 5" chuck on it the height is hardly any more than your vise with swivel base. I say rotary table rather than a dividing head as it will do everything that a DH will do and all the angles in between. Dividing heads are primarily for production work for fast indexing over a limited number of positions, and you may regret not going for a RT. Some time back,I bought a long cranked handle for moving the knee when there was something heavy on it, and the one I got on ebay had 7 castellations in it, easy with a RT at approximately 51 degrees and 26 minutes each.

Edited By old mart on 10/03/2022 20:29:54

The Elliott one shown on a recent thread was intended for that size machine (Elliott equivalent) but does not tilt.

I have the same mill. I bought a 8" indexing rotary table , with the 8" 3 jaw chuck. It was way too big for the mill table. I have since sold that & bought a 6" Vertex style & it's just the right size for the Senior. No indexing plates though. Not something i think i may ever need. Oh what have i said. Never say never.

P.S. Nice looking machine you have got there rannsachair. If you are thinking of doing any mods to it, I have a few youtube vids of the many mods done. Tom Senior light vertical

Steve.

Although a rotary table can only easily be mounted flat or at 90 deg they do tend to be a lot lower when used flat than a dividing head when it is set vertically. Add onto that something to screw onto the nose so you can hold work like a chuck and that is the height to be considering not so much when it is set a zero.

See my post part way down this page for illustration

So first best to decide what you are going to be wanting to divide, if it's a lot of gear cutting and radial holes then the dividing head is probably best. If it's a lot of axial holes such as bolt PCD are machining curved parts then a rotary table may be the better option.

Just for your interest, this is a genuine Tom Senior indexing & dividing head with tailstock.

I made a new spindle for it to use Burnerd multisize collets, and I use it on my Alexander Master Toolmaker milling machine.

Edited By Phil P on 11/03/2022 10:58:14

Further advice after looking at the main photo.

you might like to remove the vice bottom plate. Increases rigidity when milling.

Also if you have two similar vices side by side, you can hold longer workpieces between them or use one as a stop, hold any odd scrap of metal in one vice as a stop for the second vice.

Also, a ring spanner is very useful as a vice handle but don’t over]tighten it.
For Abwood vices a 19 mm ring is ideal and if you cut the handle of a ring spanner, so it is only 2 inches or so long, you can use it as a spinner to open and close the vice fast.

Simple enough to make one, index 20 on a 59 hole plate. Here's one I made for 63 and 69 divisions, as I was too idle to set up for differential dividing:

The ideal set up would be a dividing head and a horizontal/vertical rotary table. As discussed by JasonB they have different strengths and weaknesses.

Andrew

Immediately beneath the photo in thelink below, there's some text that says 'BS0 Dividing Head Manual', which is a link to a pdf (although it doesn't look like one)

Chronos – BS0 Precision Dividing Head

The point of a centre up the bore is shown as being 7.59" from the back surface, so given that the base is square-'ish' and the flange will sit level-'ish' with the end of the thread (so below the point a centre, say 1/2"?), it looks like the overall height of the flange will be about 7" off the deck with the thing pointing 'up' – a chuck will be another, what, 3", bringing the lot to about 10"… ..I guess a lot will depend on what chuck / backplate combo is available – a recess mount chuck would be nice, eh? ..is it an American thread?

I have the 3 dividing plates for the 6" RT's but lacking the 59 hole and for one probably never to be repeated scale (3mm pitch leadscrew on an imperial lathe cross slide, hence the 118 divisions) it would not be worth it. And how could you make one if you only had a dividing head?

I have the reference charts for all the dividing plates which came with the RT (3), and when looking for 118, was surprised just how many numbers were missing. This would not affect many people who are quite happy with the 24 positions common to most dividing heads, which give 2, 3, 4, 6, 8, 12 and 24 equally spaced positions before resorting to the dividing plates.