Making rubber/plastic parts: was: Ladder-shaped belt

Jules Richardson <jules.richardson99 at gmail.com> wrote: I wonder if anyone's ever managed to make rubber widgets in the home workshop? I don't mean things like repairing tape drive wheels using heatshrink tubing, but actually making the bits from scratch using some form of solution / heat / drying / vulcanising process. Probably a horrible trial-and-error experience, and maybe impossible, but I've not come across anyone who's even attempted it... Jules I have tried to make replacement rubber rollers for a Decision Data card punch machine. I first made a mold from casting resin then filed it with silicone RTV. Almost worked. The problem was that the original part I used to make the mold with had changed shape somewhat and I did not get a symmetric part. I need to get a new replacement roller and try again (they are available, at $35 each, and the punch uses 16 of them). The RTV was a two part mix that worked well. It did have a few bubbles that next time I will remove by using a vacuum. The resin and RTV were bought from Tap Plastics. Bob