This task is not too dissimilar to gear cutting. You should be able to find plenty of examples on the internet. You have not stated what equipment or machines you have to do this but a spin indexer may be a good option if you do not have a chuck on a rotary table.

Martin C

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As the old saying goes: "if I were you, I wouldn't start from here"

But, if you must … I think you will need the shortest and stiffest arbor that will accommodate blank and cutter, and some way of locking it against rotational creep. [sounds like a chuck of some sort would be very useful]

MichaelG.

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This is on a smaller scale than you are working, but may be of interest:

https://watchmaking.weebly.com/ratchet-wheels.html

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Please forgive the digression, but … I've just found this and felt I must share it:

http://wiki.dtonline.org/index.php/2100_Animated_Mechanical_Mechanisms

Edited By Michael Gilligan on 11/09/2018 19:38:09

3/8" thick! 1/8" should be plenty?

You have to fit it to a spindle, make an over length mandrel that fits the bore of the dividing head with the same fitting on the end.

Easiest shape is to use an ordinary end mill set to cut just past the centre line of the blank, depth set so each tooth cut leaves a tiny witness before the next one.

Neil

Edited By Neil Wyatt on 11/09/2018 19:34:08

Not sure what your ‘elevator lift’ actually is, or any specific details. One way or two? (like up only, or up and down)

Driving with a worm and wheel might be an alternative, as they can easily be arranged as a non-reversing drive.

Maybe look up why Fordson Standards killed so many operators, to see how effective they can be?

When my missus wanted an extra ratchet reel on her loom, I went to the local agricultural supplier and bought a couple of these fence wire strainers:-

They might need tidying and modding for what you want, but perhaps they'd work?

If you are taking a slice off a bar to make the disc, perhaps cut the ratchet first. Centre the bar each end. part part way through the bar at the required thickness, then set up between centres on the mill. After the ratchet is complete, put the bar back in the lathe, bore the hole for the shaft and complete the parting off. More solid than using a mandrel.

Ian S C

Matt, the life of the tool depends on the material used for the ratchet, brass it will last for ever(well quite a long time), steel a bit less, but I'v fly cut gears the same way as Russell, in steel. I make my cutters from old centre drills, or the shank of broken HSS taps. I use a bar with a 20 tpi thread in the Clarkson Chuck, keep the bar holding the cutter as short as practical for stiffness, my ones are 5/8" dia, although I made a new collet for the chuck

that will take 3/4"

Ian S C

You might have to turn up a spindle nose to take your chuck with a Morse taper to fit the dividing head, make it with a thread in the end of the taper to take a draw bar. Or you can do as I said earlier and you can do it between centres, and there isn't a great big chuck getting in your way.

Ian S C

Yes, no problem in brass. I made the fly cutter insert insert from silver steel, hardened and tempered to a medium straw colour. It has cut a few ratchet wheels without sharpening.

Russell

Sorry, can't send a picture as I can't find that insert at present. The holder was just a piece of 1/2 in bms cross drilled 1/4 in with a 2 BA grub scrrew to retain the silver steel insert. The insert, about 3/4 in long, was filed flat at the end to half diameter and the end angled at 45° before adding relief angles. It was touched up with a slip stone after hardening and tempering. Nothing is very critical.

Silver steel should cut mild steel OK provided you keep the speed down otherwise you can grind one from round HSS.

Russell