I'm working on a database which involves geometric design parameters, forces analysis and efficiency and losses for wormgear reduction design systems.
To determine the tangential and axial forces applied to the gear reduction system, I need to relate the Sliding velocity with the friction factor for different materials combination.
I found this graphic chart in a technical paper. This graphic is exactly what I'm looking for, but I need a curve for steel worm and a polymer (Copolymer Acetal precisely) worm gear:
I would be grateful if someone can help to find that material curve.