Ratchet wheel

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

Have you looked at clock making sites and clock pictures that will show you the shape and aspects of making a flycutter to cut it with. Also Meccano do one about 3/4 in diameter, again shows you the shape. There are some videos on youtube too specifically but not the one by Stefan which is not the type you want.

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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

This might be heresy to say but have you considered buying one? They are available for steam engine lubricators and such.

I completely understand if you want to make one for the enjoyment of the process, however if you are not too wedded to that idea you can purchase one for not much money.

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

Your universal dividing head should have come with a drive bar so you don't need a chuck. Mount the wheel on a decent length arbor and support the other end with a tail stock (can be bodged up if you don't have one) and then just drive the arbor with the dog from the drive bar. The long arbor will allow easy access for the flycutter without excess tool overhang or running into the head/tailstock.

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?

With a bit of careful marking out, a ratchet can easily be made with a saw and a file

Roy

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?

This is how I do it:

Flycutter insert is made from silver steel to match the desired profile. The slight undercut required on the tooth form is achieved by setting the flycutter tip just below centre height with the ratchet direction as shown in the photo.

Russell

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

Edited By Matt Andrews on 14/09/2018 00:57:13

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

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A good plan, Matt ... even if it does look rather like moving the goalposts

MichaelG.

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" My universal dividing head does not have a chuck so it will need to be held between centers. "

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