1. ## Thread mill on lathe using C axis

Need to thread mill in Z axis direction on a lathe, don't have a Y axis, wondering if anyone has done this using C axis?

2. I don't see why you couldn't thread mill using C and Z for lead and X for diameter. That's how CNC thread milling machines work. At least that's how the one we built does.LOL

Check with Ph Horn for indexable thread milling cutters

Dick Z

add: On our thread milling machine, the cutter axis is on centerline of Z axis but the cutter must be swiveled (tilted) to match the lead angle of the thread. If not, the thread form will not be correct.

3. What size diam thread? What's the pitch?

Seems to me that it is pretty straight forward using your C-axis as pitch in conjunction with the Z axis feeding at the pitch per rev.
1"/6 = .1667 depth in Z per one revolution of C (Pitch)

If you would like to use a "ramp-in", using the X-axis, determine the amount of approach you want in degrees and determine the feed for Z.
example; 30 degree feed-in
30/360*.1667 = Z-.01389 X would be whatever you wanted to feed into, depending on your cutter and matl., of course

4. It's really easy. You don't need to use a threading cycle, in fact, the machine doesn't even have to know what you're doing.

Index to the thread mill, lock up the C-axis, spin up the cutter, approach, then have the Z distance equal to the bottom of the threaded portion and program the C to rotate the appropriate number of degrees. Depending on your control, you may have to do it in 360deg increments....

It's actually very easy, and easy to do a finish cut.

It's the ticket when you're threading thin wall or flexible stuff.

.....Btw.....DZASTR is correct about the thread form....I would imagine for sensitive applications where you need a precise and very correct 60deg form, you'd need to have mill ground to compensate.
I've always gotten away with a regular thread mill though.