pic: Team 192's 2016 Gearbox

[Mihir Juvvadi]

Originally Posted by Michael Hill

Beautiful as always.

I didn't realize you could use timing belts without the flanges like that. I knew they (SDP/SI, etc.) sold them without flanges, but I saw they also sold flanges, so I assumed you put them on yourself. Are there any design rules about not using flanges? I didn't see anything in the GT3 design manual, but perhaps I missed it.

So the belt issues are actually very interesting. We actually machined the larger pulley ourselves, out of pulley stock, so that we could optimize dimensions, counter bore it and such.

The lack of flanges comes from several rounds of testing. When the belts are run at a reduced tension, they tend to drift around (move laterally) quite a lot less. Because we are running GT3 instead of GT2 belts and in such an arrangement where they get very good wrap around the pulleys, they do not need to be run at very high tension to avoid skipping (something that we and many others have had to do). As a consequence of all of this, even without flanges, the belts stay generally where they are (also note the slot so that a flange can be fitted at least in between the belts).

I'll get you some more pictures in a few days as well, if you need assurance that it really can drive the robot!