I am working on a roller inductor as well. What was your reason for not using a tube for the body that holds the coil? What is the minimum and maximum value for this inductor? If you don't mind me asking.
Hi Louis, I was inspired by the roller inductor of PA0LL antenna tuner. My latest symmetrical tuner has two rollers attached by a small timing belt, the value of each roller is 26 uH with a variable winding. I have made a video on the making "Master piece Twin rollers inductors ". VE2TAE 73.