I have to twist about 30 half inch bars. I was thinking about how to do it in the lathe without overheating anything important but the whole time I had this nagging feeling that I owned some thing lathe-like that would be far superior. This morning as I was getting started on the tooling I remembered that there was a pipe-threader tucked away in the storage room. Perfect! It has more torque, slower speeds, and a big through hole so I can put a piece of pipe in as a heat shield.
I spent the several hours digging it out and cleaning it up. It is a nice old machine but I would not be surprised to hear it hadn't been used in 25 years. I cut a couple of pieces of pipe for my fixture and it works fine. There is a box of dies with it that includes machine threads as well as pipe dies, so I am set for anything up to 2-1/2 inches.
I spent another couple of hours making a really cool clamping fixture to hold one end of the half inch square bar. I was almost done with the socket to go into the machine itself when I saw the problem. These machines are set up so that any length of pipe can be fed in from the back but pipe threading rarely requires more than a couple of inches of movement. The longest twist that I am gonna be able to make with that machine will be 6" long.
If I had started twisting this morning I probably would have been finished already.
The good news is that I own a nice pipe threader. Maybe in the future I will mount it to another table so that I can use it as a twisting machine. Someday when I get some of this time stuff I have been hearing about.