pic: 2471's 775 gearbox cad



This was our 2017 bunny bots drive train, it had 4 775pros, and was geared at 20ft/s in high gear and 9.5ft/s in low.
You can see the robot’s Reveal video here:https: //www.youtube.com/watch?v=WWP4iSk4PHM
the robots cad can be found here: https://team2471.org/resources/cads/

This is a REALLY nicely packaged gearbox. I love your use of the space over the drive rail, carbon fiber, and the double pancake setup. Great work!

Where do you source your carbon fiber from?

Protech Composites. They make great stuff.

so gearbox weight with no motors is ~2lb?

Love the compact design and the flipped actuators.

I couldn’t help but notice that you’re using the Sweep Lidar. May I ask what that’s for and how you’ve integrated it into your control system?

Also on another note, how do you attach the gears directly onto the 775’s. Are you using the 32dp gears from VEX/WCP?

Thanks! it took a lot of tweaking in cad, but i am pretty happy with what i ended up with, but as always there are little things that i want to change.

we are still working on the lidar, we are currently trying to use a Intel UP bored as a co-processor for it and connect that to the robo- rio

the gears on the 775’s are from Andy Mark (am-0928), at the time we made this the pinons from west-cost where unavailable, so we got these ones and rimed them out to the right size, we didn’t like them that much so we bought 12 tooth stock from mcmaster and have made ones a lot closer to the ones you can buy

The 85 tooth gear in also from Andy Mark (am-3533)

I haven’t weighted it without the motors, but vex says a 775pro weights 0.8lbs so it would probably be around your estimate 2lbs.

How did the motors hold up throughout the competition with just the two bolts supporting it? Where they in danger of falling off at any point?

We didn’t have any problem with the motors falling off, we use a little bit of loctite to insure the two bolts wouldn’t back out