A peek into the heart of our drivetrain this year. Its our first year to use non-kitbot trannies, and aside from uniqueness - this unorthodox solution had some nice features that tided us over in our design.
Any others out there with a setup quite like this?
That is what it is. I for some reason thought that they were made out of copper, but now that you say brass or bronze it all clicked.
Just to warn you, that these 2 metals are relatively soft. If to much force is exertaded onto them, it will strip the 2 gears.
This is our gearbox for our wings in 2003. However we started noticing severe wear at our first regional. By the time we got to nationals we new that it was pretty well gone. The brass gear that you can be seen (the gear that is cut to only 1/4 of a gear) was completely stripped.
Now i haven’t thought about it in so long, and i don’t know the exact force that was working against the gear, but im pretty sure that it is less than some robot will be pushing against you with.
Hopefully you thought it all out before deciding to do a worm gearbox.
That grease won’t help them if they collide with another robot at high speed… I remember from 2004 and prior about people using the drill motors with their gearboxes, without removing the anti-backdrive pins, and completely destroying the internals during impact with other teams.
I would at the very least look into the fact that there may be a problem down the line, and ways to fix it, if I were them.
As far as worm gears go, its a relatively low reduction. We used a quad-thread worm - which really makes it roughly halfway to a helical gear set. This means it is backdrivable, but is notably more resistant than standard gearing. Also the quads appear to be able to take greater stresses than comparable single or double threaded worm gears, although I don’t particularly know why.
It is a bronze worm gear with a hardened steel worm, as mentioned in previous posts.
I have checked the numbers as best I can and I think they’ll hold up to the abuse that the robot is bound to see, but we’ll be running them in and doing some heavy testing in the next week or so to see how they hold up. The biggest unknown is the shock loading like Cory mentioned, so this will be something we will test for. There is still room for some changes if they don’t seem to be holding up well enough - but for now we’ll just keep those in our back pocket until the need arises.