I finally got around to making a skin stretching rig - I’ve only tested it with cloth so far - I have 2 goat skins to try on it (probably tomorrow).
I ended up using a semi-traditional shamisen method, combined with a taiko method, but with the idea of “lifting” the dou up to make the stretch. The dou is on a pedestal that I can crank up, using that nut and bolt set-up in the middle, and reaching in from the outside with a wrench. It’s a little awkward, but the pedestal will go up about 4 inches. I was thinking of making a “prestretch” form that had a higher middle so that I could get a more uniform stretch. (Maybe like a wooden dome?) The photo shows the dou with my polishing cloth on top of it.
I used tarp clips for the kisen. (The thought of making 20 individual kisen gave me such a headache, lol). I found about about tarp clips on the taiko building board on Facebook, and they seem to work pretty well, so I thought I’d give them a try. The harder you pull on them, the tighter the grip.
Anyhow, I’ve only cloth tested it so far - I’ll let everyone know how it goes!