Twisting Lathe

[Rantalin]

This isn't a question, so much as an interesting piece of equipment I happened to hear about today. I was getting my car inspected and there was an old anvil on the workbench at the garage. The Mechanic that I was talking to was thinking of taking it to Old Sturbridge Village in MA and taking blacksmithing courses. He is currently a woodworker, turning logs into bowls and such, in addition to working at the garage. He told me about this guy that hooked a 4 speed car transmission up to a lathe and kept one of the ends from turning. He would put a piece of hot metal into the lathe and slowly twist it, then put it into reverse and twist back, creating different twist designs. I thought this was a really nice trick that I would share with everyone.

[Strine]

Rantalin
It's amazing what people come up with. A pro blacksmith up the bush was getting rid of all his gear due to a restrictive medical condition. I went up to proffer my commiserations and perhaps help with the disposal. Under covers was a twisting machine that would twist anything, especially hollow square tubing up to about 15'. From the examples laying around you'ld swear he'd filled them up with something to make them act like solid bar. Not so, it was just a really good machine. So good that he wouldn't lift up the covers to reveal the secret unless the colour of my money was displayed. He told me the thing was so simple just showing a dill like me would spoil its uniqueness and blow any chance of protecting a patent. "No worries mate" I said

As for anvils in garages. That's where my 187 pounder come from. I spotted it in the corner and asked what he used it for. Apparently he just used it on bits and pieces; nothing too elaborate and certainly no heat involved. I suggested a swap with my 100 pounder to which he said bring it around. So I went to the bank, then home to load up the anvil. He was more than happy with mine. "Give us ten bucks and the deal's done". I slipped a disc in the rush to get my wallet!!

[HWooldridge]

I've seen a multitude of twisting machines. The fancy ones are CNC driven and can be programmed but the basic concept is to lock one end, drive the other at low speed/high torque with a clutch to stop the motion in an instant. The old shop I restored in New Braunfels had one from made with a model T transmission and a flat belt for power. It was used for both twisting and threading so the head stock was set on ways to allow the work to slide at it was threaded.

A friend of mine built one with the head stock and a 4-jaw chuck from an old wood lathe. The bed was an 8x10 wood beam that would allow about 8 feet of twist between centers. It ran too fast so he built a speed reduction with belts and pulleys that made the final yield about 10 rpm. With a 3/4hp 1725 motor, it would twist 1 inch square hot and 5/8 cold. The clutch was simple - he just engaged one of the belts by hand with an idler, then let it slip when the twist was completed.

[Coalforge]

I use an old "Rigid" brand pipe threader. It turns about 20 rpm. Doesn't stop instantly but you can figure out the lag. I haven't tried square tube in it but will after reading the above post.