[Mike Martus]

Official answer: Mike Martus

That material has several names: Poly Cord, Cord , Belting.
It is sold at many industrial supply companies. many of us get it from McMaster Carr. It is sold by the 25, 50 and 100 ft spools and is available in several colors as well as diameters.

Here is the problem.
The material has a unique property of being able to cut it and re-join (splice it) the splice is as strong as the cord and has low failure. Great stuff!

Problem: to splice it together it needs to be melted. The best way is by a small flame (butane torch). This is NOT allowed because it is an open flame and not safe at events or even your school shop.

Using a "Heat Gun" IS allowed however caution should be used to avoid burns to the hands. Splicing or making a "Good" splice is tricky. There are professional devices that will do the splice but the cost +$450.00 violates OCCRA Rules.

Poly Cord is a great transfer of motion and has a good coefficient of friction.

I hope this helps. Good Luck!