Team 1625 Midwest Coast Drive
-6 Wheel West Coast Drive
-Completely belt driven using Gates GT2 Belts
-5mm GT2’s in the frame
-3mm GT2’s on the gearbox
-Gearbox contains AndyMark Gen 2 shifter gears and dog
-Custom CNC’d hex axle’s
-Shortened body pancake cylinders for the shifters within the gearbox
-Single Bolt roller bearing tensioner on gearbox
-Cam based roller bearing in frame tensioners
-Wheels made of UHMW for cost purposes
-Built in encoder mounts
-Testing will be done soon
(Sorry it is a couple days late, and sorry for the resolution of the photo’s)
Neat! With belts and only two total reductions it probably sounds pretty slick when driving around. Are the motors being used as a means of structural support between the two transmission plates? It looks like ‘fun’ to take apart and put back together.
1625: the only team not satisfied with a six wheel swerve drive
How much weight are you saving compared to that by the way?
I love running the belts through the tube. I was trying something like that but I didn’t think to use belts. Makes so much more sense since you can order them an exact distance and they don’t stretch or fail often.
Yes, the bellypan was designed with the current layout in mind. There is a mounting layout for the electronics and pneumatics. There is probably an excessive amount of hose, but we always cut the hoses long to begin with. We will probably cut off the excess eventually.
Looks pretty good so far. The transmission layout is rather clean. I’d be worried about the belts in the tubes though. It seems like if one were to wear or break at an inopportune time (say during Einstein finals), you’d have a heck of a time replacing it. And don’t think it wouldn’t happen. All it would take is one piece of sharp debris to find its way in there.
Also, I’d be very concerned about the strength of a three spoke wheel, at least with the spoke profile and material you’ve chosen.
We plan on doing time trials to see how long it takes to replace a belt. We also plan on putting lexan shields over the access holes in the frame to prevent sharp debris from coming in contact with the belts. Also the wheel in the CAD is just a placeholder. The real wheels are made of UHMW that has been shelled out an only has one hole for access to tensioners.
1/32" polycarb could be riveted over the holes to prevent debris from cutting the belts. The obvious tradeoff is increased time to repair.
What I really like about this design is the ability to change the overall gear ratio VERY quickly. In the Quals, perhaps it would be better to be faster in one match since you’re the dominant robot and a low gear at 7-8fps is fine. Yet perhaps in another match you will face a superior defensive robot, thus you would opt for a lower gearing option (5-6fps low gear) in order to push through defense. 2 pairs of large pullies with respective-sized belts would be a simple way to add that versatility.