Tuning machine gear material

[dp]

What is the cutter made from?

[3jaw]

What is the cutter made from?

A2 tool steel.

[Tinkerer]

Did you cut a straight worm drive and feed the cutter into it to get the curve?

[DICKEYBIRD]

Bee-yoo-ti-ful!

Please do post pics of the tooling. This kind of stuff fascinates me.

[Peter.]

Very nice 3jaw!

[Reed]

Nice Job!

You mentioned the following and I'm rather curious which way you went. Guessing you made the cutter on the mill since it is a square tooth, but how did you end up doing it.

I'd think chasing the spiral on the worm is necessary similar to gashing a gear would be, this correct?

Thanks,
- Reed
Raleigh, NC

I plan on making it as original as possible. I had thought of the rotating toolpost geared to the spindle idea as a last resort, but I have another idea that is practically identical to your second suggestion. Instead of cutting a straight worm and using that to make the cutter, I am thinking of making the cutter on the mill using a dividing head and a single point fly cutter ground to the proper geometry, adding some clearance angles, then hardening and sharpening. I do like your idea of cutting a straight worm first and using that as a "cutter to make a cutter", though.

A2 tool steel.

[davidh]

nice results, creative thinking. i love jobs like that. .

[3jaw]

Did you cut a straight worm drive and feed the cutter into it to get the curve?

That's it in a nutshell. I determined through measuring the original that a 7 TPI worm would be close enough to the circular pitch of the cutter to get it started. I cut the worm 0.040 deep with a tool ground the same as the tooth form of the circular cutter, then I switched to the circular cutter and finished the worm. I had to go very slowly and use lots of cutting oil.

The cutter teeth were made on a vertical mill with a right angle angle attachment and a "spin-dex" fixture set at the helix angle of the worm. This is also the same setup used to cut the gears. I made a fly cutter to hold the cutting tool. The cutting tool was held at the correct angle in a grinding vise with an angle block that I had to make and then mounted the vise on a sine plate and ground on a surface grinder. I had to make the angle block and use the grinding vise since I don't have a compound sine plate.

The whole thing was a leap of faith since I wasn't sure my idea would work but, to my relief, it did work just like I had planned.

I don't think I'll take on any more challenges for a little while!!!