I've used teflon tape for my own focuser projects and it works quite well, I was lucky enough to work in an industry that used teflon tape of varying thicknesses and managed to salvage some end of rolls before they were tossed in the garbage by operators who didn't realise the value of the tape to amateur astronomers / atm'ers.
I've offered some of my leftovers to Alex and hope it works for his project.
Jeff
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