by raimundo » 16 May 2008 10:44
bristles found on the street need to be inspected and often many of them are thrown away, you need to know how long the part you are looking for will be, and then find bristles and clean them before inspecting them. any that are brittle, excessively rusted so that they don't clean up well also can be thrown away. however, if you are thinking of making the flat bend as shown in kaotics thead linked above, or even just bending and twisting, you can get valuable experience by practicing on the bristle that is too deeply scarred or rusted. Then when you are sure of your technique, Use the best parts you have.
There is another way of making a two pronged tensor, with just one piece of metal, this is done by folding a piece so that both ends point the same direction, you cannot make the hairpin bend really tight as that will break the metal if done cold and it will weaken it if done with heat.
The answer is to have a bend that is made over a mandrel like a screwdriver shaft. preserving the round curve, light heating and near cold bending are best. Cold bend as far as possible and then heat while pinching with a plier to quickly press it to the diameter of the mandrel.
excess heating will weaken the metal. All this can be experimented on with the scrap bristles til your technique is good.
this will make two ends that can be twisted between two pliers near the tips, and these ends can be filed to fit, This will make a double pronged tensor that has a weakness in that it is too mobile, the weakness can be corrected by installing a cross piece that is just larger than the radius of the bend, the two ends should go through holes in this cross piece.
as the crosspiece moves outward along the prongs, it will adjust the spread of the two ends. again, a little experimentation will solve the problems that may arise.
Wake up and smell the Kafka!!!