I am hoping to use WCP’s GT2 pinions and pulleys with a 775Pro, but I’m unable to find the correct formulas (or online calculators) to get the center - center distance between the motor and the driven shaft. SDP-SI’s calculator only goes down to 16T for GT2 3mm pulleys. It goes down to 12T with GT2 2mm pulleys, but it looks like the pitch affects the needed C-C distance.

In this thread Austin Schuh recommends modeling the belt in SolidWorks, but I don’t entirely follow all the details. (For instance, do all of the arcs just butt up against each other? What is the diameter of those arcs?)

Various other formulas I have found don’t take into account pitch and tooth profile, so I’m not sure which ones to trust.

I would greatly appreciate any information on calculating distances for GT2 3mm belts. Links to the correct formulas, explanations of the post I liked, etc., would all be great. For reference, I am hoping to use the 12T pinion with a 36T pulley and a C-C distance around 4".