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Anyone have plans for a bar twister before I start engineering my own plans

.. I'm looking to hot twist 1" to 2" bars in max 1' sections. 

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Thats some hefty twisting! How many twists in the 1'? As Ian asked are you doing this by hand or with mechanical assistance?  It will be fairly hefty equipment either way!

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Good friend of mine uses a pipe thread machine to grip and drive his heavy threading .  He takes advantage of his heavy platen table to anchor it and the other end.  He uses a heavy duty oxy/acetylene torch to regulate and control the location of twists. 

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Greetings Griffin , 

In my old shop I twisted up to 1 inch cold with an adaption to my Eagle rolling machine.. I also designed and built a twisting machine that I could do up to 10 foot cold of 5/8 .. Two inch is a whole other thing. The biggest problem will be holding it to something solid.   In the past I have used my acorn table. What is the quantity that to plan on twisting? 

Forge on and make beautiful things

Jim

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I remember seeing a homemade twister 10 - 15 years ago that used a handheld threading machine powering a reduction gearbox that had the output shaft as the twisting head.  The stationary head was adjustable horizontally to allow twisting various lengths and a pipe was used as the rail for the stationary head to move horizontally along.  Two pieces of 1/2" square were welded along the outside of the pipe to act as anti-twist keys for the stationary head.  Initially the builder used an I beam as his rail but said that it twisted up like a corkscrew from the torque.  I saw this twister twist a 1" square 10 foot piece of steel cold without a problem. 

Just a few ideas if you decide to build it yourself.

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I have heard of someone taking a truck transmission to use as a multiplier for a twisting set up. Food for thought. 

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I have heard of someone welding 2 crescent wrenches by the handles to a square bar, then putting the bar in a vice. They put their material in the 2 wrenches then used a third crescent wrench in the middle of the material to make the twists.

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I have seen one that was made with a large worm gear (from an old elevator) mounted on an I beam.  A chuck of sorts was mounted to the output shaft and was a welded steel affair using large socket head screws to hold the work piece.  The tail stock was a large pipe vise that was mounted to a plate that had large bearings under the flange of the beam.  This allowed the whole tail stock to move as the work piece became shorter during twisting.  Work was placed in the twister hot and a rosebud torch was used to keep it hot and to concentrate heat where tighter twisting was desired.  Quite capable of twisting 4" stock when at heat.

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I'd like to build some thing essentially like a pipe threading machine with a gear reducer, mounting to a beam sounds reasonable..I have an acorn table I could mount it to as well. And yes I do have a 14 x 40 lathe that I was contemplating for this application. Thanks all for the input! 

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On 16 January 2016 at 8:07 PM, griffinforge said:

Anyone have plans for a bar twister before I start engineering my own plans

.. I'm looking to hot twist 1" to 2" bars in max 1' sections. 

 

On 16 January 2016 at 8:17 PM, ianinsa said:

Manual, mechanical(hydraulic, electrical)?

 

Buy a HEBO machine?

 

It all depends whether you are looking at large quantities or just section capacity. 

 

Powered makes sense for production, but if it is just for the occasional element the low initial cost and the reduced maintenance of a manual machine is a consideration.

 

Powered means you can do heavy stuff and lots of it, manual would likely give you more precise control on overtwisting and spring back if working cold.

 

A good windlass works wonders, whether one or two man. It overcomes the main difficulty with powered ones of being able to stop them precisely enough.

 

I still have some unused 50mm (2”) plate profiles of a twisting machine I devised decades ago, but the job did not materialise. It was going to be bolted down and the spindle then turned in 90˚ increments by lifting a large spanner/lever/wrench with the crane. 1 tonne lift +  2metre lever = some torque!

 

I have done a few hundred 20mm (3/4") square balusters cold for a light well staircase using a four jaw chuck in both head and tailstock of the lathe. I pulled them around with a C spanner with a long handle. I used a copper split sleeve to prevent any bruising by the jaws on the show part. I could be very precise in order to align either end.

 

One of the main advantages of machine alignment over freehand is that you get very regular twists if you do it cold.

 

One of the main disadvantages of machine alignment over freehand is that you get very regular twists if you do it cold.

 

They can be really boring!

 

The most stunning example of twists used on an architectural piece I have seen, is the balustrade around the courtyard of the Picasso Museum in Paris. Very simple light handrail with twisted balusters from around 20mm (3/4”) square. The “twist” is that they are all different. Fast, slow and any and every combination of fast and slow within the same bar. The whole thing shimmers, incredibly vibrant… barbaric, in a good way!  The opposite approach to the normal black smithery ideal of using water to quench out and slow up the bit twisting too tight. 

 

Alan

Edited by Alan Evans

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