Glenn

Show me your twist

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Glenn   

Show me a twist that you put into steel, and describe how it was made.

It can be a simple twist in square bar, a pineapple twist, a cube twist, a wheat twist, a decorative twist, and the list just goes on and on.

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John B   

BP

We have just done a twist course at Westpoint this weekend, here are some of my notes







TWISTS IN BARS











NOTE: Twists can be right handed or left handed







Tools used when producing these, Forge, Anvil, Leg vice, Hammer, Centre punch, Hot set (Hot chisel/incising tool), Appropriate tongs, Twisting wrenches, Water dipper, Water tank/supply, Wood block and rawhide or wood mallet and a Wire brush, and a sacrificial plate for cutting through on the cage twist in solid bar to prevent damaging anvil face.

Right hand are illustrated pictures are large for ease of understanding method and appearance.














HOW TWISTS DEVELOP






12mm square bars used in sample pictures







From Basic Twist to Cage Twist







Done Cold, produces an even twist but it has a limited length of pitch before it shears, in practice it is limited by ability to apply pressure on wrench and grip on other end.











post-816-0-86075300-1311580687_thumb.jpg





Done Hot twists can be tighter (shorter pitch)











post-816-0-77991200-1311580743_thumb.jpg










Two sides incised on the centre line and twist, Appears like Two flat bars twisted together







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Four sides incised on the centre line and twist, Appears like Four square bars twisted together











post-816-0-19406100-1311580853_thumb.jpg






Four sides incised on the centre line with a pair of opposite corners knocked off into a rounded edge and twist,






Appears like Two round bars and two square bars twisted together











post-816-0-50620900-1311580906_thumb.jpg






Four sides incised on the centre line, all the corners knocked off to form a rounded edge and twist, Appears like a Rope twist







post-816-0-20813300-1311581040_thumb.jpg






Four sides incised on the centre lines, then split right through, (this could be from all four sides or just two)







The bar is then twisted a known number of times, and then untwisted half the number of turns whilst pressure is exerted to push the split part of the bar back into itself, compressing the twist and forcing the cage outwards to the required shape, adjust if required. Cage twist pictured is a parallel sample,







post-816-0-38768800-1311581262_thumb.jpg







These twists are all made using the same basic twist and using different numbers of incised lines on the centre lines, if you move the position of the incised lines before twisting, and forging the corners, you will get even more different effects or appearances. The combinations are only limited by your imagination.












Here is another sample that is similar but different to a previous one shown. This one has four sides incised, not on the centre line this time, but near and adjacent to two of the edges, with the two opposite corners knocked off into a rounded edge.


















Another variation is a small flat is forged the length of the twist on each corner/edge, an incised line is applied on each edge and then the bar is heated and twisted. Ribbon twist







post-816-0-46731700-1311581719_thumb.jpg










Or these, sometimes called Water twists











Incise two opposite sides near to the edge, the length of the twist section required, and then make a short ¼ twist, then make a reverse ¼ twist at the desired spacing, and repeat along the required length











post-816-0-78112100-1311581959_thumb.jpg






Or increase the twist rate to ½ turn and reverse ½ turn











post-816-0-96727500-1311582000_thumb.jpg










Same but different for comparison ½ twist gives a chunkier appearance







post-816-0-79675700-1311582031_thumb.jpg






Or you could do these twists in the same direction (no pics available)







If you apply the same principle about development and you can produce a pineapple twist, or three separate styles of twists starting with;








A square bar is twisted, then the twist’s high spots are forged back to the original square bars’ size











The bar was differentially twisted as opposed to equal twists, and you can clearly see the difference it makes in the appearance of the facets. This was due to lack of uniform heating throughout the twisting operation







post-816-0-70559800-1311582372_thumb.jpg










If you then reheat the bar and reverse the twists, you get a Knobbly effect











post-816-0-17807800-1311582543_thumb.jpg















However, if you incise the four sides on their centre line, twist a known number of times, then flatten to square, incise again on these ‘new’ sides and reverse twist half the number of previous twists, and if arranged correctly will give a Pineapple twist or Diamond Twist effect











post-816-0-89119500-1311582597_thumb.jpg











This from iforge source Cube twist











Incise down centre line on all four sides, then cut using a hacksaw or thin blade on angle grinder the equal sections diagonally across opposite edges











post-816-0-04624400-1311582961_thumb.jpg





























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Edited by Glenn

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John B   

Had an opportunity to have a play for a couple of hours, (don't have many of these now) and so here are the results, material was 5mm bar, in a coke forge.

 

post-816-0-23261400-1405018862_thumb.jpg

 

A couple of the corn on cob /twisted/braided variations,

 

post-816-0-11856400-1405018623_thumb.jpg

 

And a first and second attempt at the Claydon Knot, without any special tooling, just using anvil, bending forks and swage block/pritchel hole on anvil and punch

 

Didn't particularly like the first attempt, didn't quite look right 

 

post-816-0-69104400-1405018641_thumb.jpg  post-816-0-26304900-1405018669_thumb.jpg

 

Second attempt looked better, but with a couple of mistakes, not symmetrical, and a miscut on one of the component bars

 

post-816-0-46132600-1405018917_thumb.jpg  post-816-0-60620700-1405018934_thumb.jpg

 

We have a multiple twists course this weekend, so may have a chance to pass these on if we have time outside scheduled programme.

 

Had fun, darn I miss my forge.

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