Center to Center Distance in Power Transmission

[artdutra04]

For timing belt center to center distances, I've always used the SDP-SI Belt Calculator to easily run through various options of available belts and sprocket sizes. The timing belts used in FRC don't stretch any appreciable distance, so I always use the exact CTC distance and have never had to use a tensioner.

[chadr03]

I have measured a few AndyMark gears for tooth thickness and they have all allowed for .005 to .010 of backlash at standard centers which is about where you want to be these types of transmissions. I would recommend a -.000 to +.003” CD tolerance on gearing.

Just remember a little bit of backlash is a good thing. You will destroy a gearset quickly if they are in a tight mesh.