Just a vague recollection here. Am not an R/C guy (maybe someday) but thought I'd seen it in a store. There is often some heavier stuff like this in the typical LHS brass/aluminum tubing racks. The homemade ones I've seen were thin metal strips with (or without) rounded edges, and some fine tubing that was squeezed through a small roller tool that was likewise handmade for this purpose. IIRC, the tool's mechanism was akin to that of a manual can opener. The guy who made the roller tool is Arlo Schroeder in Kansas, a true master of the art, who scratchbuilds fantastic 1/16 biplanes, et al.
Thanx for the info..