low friction pulley

[markusic]

I am designing a force calibration rig for an electric propulsion thrust stand. The design requires a pulley to support the loading of calibration weights. The pulley needs: to have minimal friction, support about 100 grams, physically 1-2 inches in diameter, and have an edge groove that will constrain a thread-sized string.

Does anyone know of a supplier for such a pulley (price is not important)? What type of thin strings are available? Spider wire?

 

[EnglishMuffin]

Suggest

http://www.singhlascientific.com/physics-1.htm

with nylon monofilament thread.

Only snag is, I don't think those pulleys are ball bearing - although they are designed to be low friction for lab experiments. You would have to check.