Have anyone replace VPI SSM belt with string?

Having recently added Mark Kelly's speed controller, I've been experimenting with Stren braided fish line as an alternative to carpet thread on my TNT with flywheel. Braided fish line offers the theoretical advantage of very low elasticity. I chose 20 lb. Stren because its diameter is about the same as carpet thread & the knot is small.

The experiment was a failure. The exotic coating on the line grips poorly relative to cotton thread. Poor grip together with zero elasticity means that the fish line must be tightly tensioned to the point that the motor will not start without a push. Even with a helping hand to get started, there is audible slippage.

Cotton/poly thread works much better and its elacticity somewhere between rubber and fish line appears to be an asset.

I've used carpet/button thread with a TNT III/flywheel set-up and can report quite an improvement in focus & musicality & relief from slurring in the bass region. If the string can't be tensioned, the tricked is to tie knots within knots to the point that there is enough tension for friction, but not so much that you hear the knot ping when passing through the pulleys. If you can get this working you won't go back to rubber bands. With a little practice you can get two threads +/- 1mm.

Semi, yes with the TNT/single motor/flywheel it is easier because only the long thread around the platter must be cut exactly in order to be self-tensioning.