Old Methane Gas Cloud
Join Date: Jun 2009
Location: Huntington Beach, California
In metal, all it takes is a lathe with a lead screw to drive the tool holder along the bed. Pardon me on the terminology, It's been over 35 years since I touched a metal lathe and turned a thread.
On a wood lathe (I've never used one.) I think that if the tool rest is at an angle to the lathe bed, and the cutting tool has multiple teeth like a comb it might be easier than you think. Make the leading teeth shorter than the following teeth and the tool should guide itself into the stock.
If I remember correctly, the points of the cutter should be 60°, the distance between the points should be 1/TPI or threads per inch and the depth of the full cutter is half 1/TPI times square root of three. (TPI is threads per inch)
Anyway it would take multiple passes to get the threads that you want. I think that to cut the inside threads you would need a symmetrical cutter.
I'm sitting here after a couple of hours at the machine, two drinks and net gain/loss was zero. So take the above with a bit of vodka and a twist of lemon.
Use the right tool for the job.
Rich (Tilting right)
Huntington Beach, California
Remember that when we have the "BIG ONE" everything east of the Rockies falls into the ocean.