Twisting 2" square tube and 1" square steel

I want to twist 2" square tube and 1" square steel. I have a pipe
threading machine I would like to use to do this with however it
doesn't have the torque needed to twist something this thick. I've
heard of folks adding a gear reduction box or old transmision to the
end to increase the torque but not sure how to go about it, what kind
of tranny or gear box, etc. Looking to see if anyone out there has done
so and how they did it.
Thanks
Reply to
pccruiser
Loading thread data ...
Whatever you do don't try to overload the pipe threader, you'll likely just destroy it.
I expect you'd need to make a custom rig for this and probably need an O/A torch to heat the tube being bent. Perhaps a rig based on a length of used I beam as a base and a big used industrial worm gear reduction drive.
Pete C.
Reply to
Pete C.
This is a blacksmithing technique. Heat the area you want to twist to a red heat, then, working quickly, put one end in a vise and grab the other end with a twisting wrench and twist. You don't need much force when the metal is hot.
1" square bar is pretty stout stuff. This is serious forging. You will not have a prayer of doing this without heat.
GWE
Reply to
Grant Erwin
Great advice, Grant. And find a piece of pipe that you can sleeve the square steel with so it stays straight. Slip it over the steel moments before you twist it. Have some way of keeping track of how many degrees you twist it, or your "candy cane" will have an uneven spiral. They're easy to straighten if you don't use a sleeve, but it's just more work. Unless one really kinks on you, then it's usually toast.
Use a "rosebud", or forge, or weed burner to get - r - hot.
Steve
Reply to
Steve B
You'll need a forge big enough to heat a foot or so of the material at a time. If you use a torch, you'd better have a pretty big rosebud. Twisting the 1" square bar is no problem, but to twist the 2" square tube, you need to find a piece of pipe as large as will fit into the tube. This will hold the tube in shape while you bend it. If you only need to do this once, find a blacksmith and make friends. Most of us like to show off a little now and then. If you need to do this often, consider obtaining a propane powered gas forge like this one:
I know a guy who twists 1/2" square bar cold with a farm tractor. He places the 20 foot bar into a piece of water pipe so it won't kink, then anchors the far end of the bar. The near end hooks to the tractor's pto with shop made clamp. He has a Veeder Root counter rigged to count turns. Engine at idle, engage PTO. Plently of HP to do 1" square, I'll bet (but not with my tractor).
Pete Stanaitis -----------------
pccruiser wrote:
Reply to
spaco
I have beside me, a small table made by my Grandfather; it is made from 1/2" square wrought iron with the individual legs twisted over part of their length. Assembly is done with countersunk FH machine screws, the top is a slab of brown slate set in 3/4 x 3/4 x1/8 angle notched and bent at three corners, the fourth corner is welded, but nearly impossible to detect. One of grandfather's stories concerned a set of fireplace tools he had made, the customer saw the first handle which had twists in both directions separated by straight sections, and insisted that it be used as a pattern to cast handles for the set. Grandfather bet him a dollar that he could forge the set without a problem making them identical. When the customer came to pick up the set the next day, he paid the dollar bet with a five dollar bonus. This would have been in the 1920's-'30's so a dollar bet was serious money and a five dollar bonus could make a blacksmith's week! Gerry :-)} London, Canada
Reply to
Gerald Miller
I saw this done by the artist that did some decorative railing. He built a 20± foot long furnace which was basically a 6" round metal pipe with a burner the full length. Burner seemed like a 1/2" pipe with a bunch of drilled holes for the flame. Within this furnace he would suspend his 20 foot long square bar, anchor one end and twist away at the other end. The spirals were very uniform.
Ivan Vegvary
Reply to
Ivan Vegvary
All of these are great suggestions however I want to do it cold, no heat. I already twist 3/4" steel cold with no problem but that is the max my machine will do without some additional torque. Doing it with heat makes it very difficult to have it uniform and I have multiple pieces to do. I'm looking fo advise on getting a cheap gear reduction box such as an old tranny but I'm not sure what to look for. I know that there are folks out there that have done so and I was looking to hear from them as to what they used and resouses to aquire it.
Thanks again.
Reply to
pccruiser
Okay, I have seen such things as this. Almost any manual automobile transmission you can find will work, since you only need a couple of HP to do the job. Some people have put 2 transmissions in series to get lots of (adjustable)reduction. I built chucks for one of these for a guy a couple of years ago. I think you want the final output to be about 10 -20 rpm.
Pete Stanaitis ---------------------
pccruiser wrote:
Reply to
spaco
I would worry about whether the frame of the machine were up to the job. IIRC the 1" will be about 3 times stiffer than the 3/4". If the machine is up to it then the differential gear and drive pinion from a front wheel drive car _might_ be adaptable. Not an auto gearbox unless its one with a significantly bigger than 1 1/4" dia output shaft for obvious reasons.
A shaper bull wheel and drive pinion would be easy, or most easily, an auto flywheel/ring gear and starter motor pinion.
Mark Rand RTFM
Reply to
Mark Rand

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.