I'm trying to create a setup to transfer motion from a motor to a shaft that requires a much higher torque (bi-directional). The housing is about 6 inches long and the speed ratio needed will be around 1:10 or even 1:15 and I'm looking at using a GT3 belt with 14mm pitch. The reason for 14mm pitch is that the datasheet appears to suggest it is the GT3 that can achieve the highest speed ratio. However, according to the data sheet, the highest speed ratio specified is only 6.857 (28:192) - does that mean the belt isn't designed for running in setups with higher ratios? Also, the shortest centre distance between the pulleys is 27.9 inches:
If the speed ratio was to be pushed to ~10 (16:168) and the sprockets were just 5 or 6 inches apart, could idlers be fitted in between to give the belt and the sprockets better contact? Are there tips to setup such high ratio sprocket combination inside a small housing?