I'm working on a project, and I need to make coils out of 5/8" diameter copper rod, ideally with center line radii ranging from 3 - 10 cm, and with turn heights of 5 cm. Most metal shops near me don't have the capacity to do this, because there rolling machines are based off of cold bending. I have formulated a design with which to make something close to these coils in shape, though it remains to be seen whether or not they would then be able to handle my currents. I plan to feed the rod through a flame (i would prefer an induction heater but cost is against me) heat the rod up to about 95% of its melting point (about 1000 C), then immediately feed the hot end to a cylinder to which I will attach a clamp to hold the end in place. I will use a gear system to control the bending ( when the cylinder rotates once, it moves 5 cm horizontally). A problem I can see is that the copper will oxidise, and the granular structure of the rod (which is helically planed) will be altered, which may affect conductive properties. I would like to hear your thoughts on this as well as any other practical alternatives which you may have to my method. Also I wasn't sure which forum to put this in, please move it if necessary.