In class we are building a drive train. We have a number of parts and are working out where to mount everything. We plan to use a Gates HTD Timing Belt, 15 mm Wide 104T (am-2267)
The pulley on our wheel is the Pulley, 42 Tooth (am-2234)
The pulley on our gearbox is the 39 Tooth HTD Plastic Drive Pulley Kit (am-2361)
Tip: when you don’t know what pulley you have count the teeth!
West Coast Products has a belt calculator. Enter the number of teeth for both pulleys and then modify the desired center distance until the belt with the number of teeth shows up.