I was thinking on the knobs i plan on making for my bass coming up, im using split shaft pots, so the knobs i make are going to be punched out with a hole cutting drillbit and all that then make the shaft hole 1/32 '' bigger than the shaft, and fill the hole with clay then press it over the shaft and squeese the exess out to get the shape of the shaft in it, then let it harden. it may not work, but if it does ill post a tourtial of how i did it.