It’s been a while since our team last used custom gearboxes.
These will be featured on both our competition bot (which will be attending IRI) and our practice bot (which will be competing in China)
Total Weight: 8 pounds per gearbox (minus encoders)
Ratio Breakdown: 12:100 -> 54:54 -> 18:66 -> 20:70
The goal of this gearbox was to replace the versaplanetary gearboxes we were using on our elevator which kept breaking in a variety of ways.
In order to fit this gearbox we had to design it to be as slim as possible (which is why we used a funky 54:54 stage).
Not featured in both photos: AM Mag Encoder using the RedLine Encoder Kit from Andymark
Feel free to ask questions or critique the gearboxes.
Still trying to figure out that 54:54 stage. It seems to me that if you removed that stage, and put the three axles in a line or near-line, pointing a bet left of up relative to the motors in the pic in this thread, you could have done all of this in three spur stages with no need for additional width, esp. if you did the 20:70 as the middle stage and 18:66 as the final.
Sorry if I misinterpreted your reply but the reason for the 54:54 stage also lies in the fact that the current setup of our bot doesn’t let us fit the gearbox without the need for the motors and the output shaft to be in those exact positions. I also needed to convert from 32 DP to 20 DP somewhere in the gearbox and the only way that I know how to do so is by running the two gears on the same shaft. I will be uploading a photo and video later with it on the bot and running.
The plates themselves don’t have any motor vent holes but we did purchase some 775pro vent plate spacers from andymark (http://www.andymark.com/Vent-Plate-p/am-3650.htm) for the fact that it made it easier on our machinists to make the plates and that they’re red
Agreed that the same shaft is the best way (only other solution that comes to mind is a belt or chain). My idea was to put the 20t 32dp on the same shaft as the 100t 20 dp gear - or could you not find a par with matching bores?
Unrelated to your gearbox, but I notice you are using Orange BaneBots Wheels on your drivetrain. I have always been under the assumption that they’d be chewed up too quickly to be worth the high traction they offer. What has been your experience with them on the drivetrain? How often do you replace them?
We originally had eight 6" pneumatic wheels on our drive train with a drop center. However, they resulted in the robot bouncing around a lot and making our auton routines quite inaccurate. We decided to change the outer 4 wheels to 6" omnis and they have worked quite well for us.
The banebot wheels actually never touch the floor due to having a smaller diameter than the omnis, except when we’re driving over the platform. Their purpose is to make sure we don’t get beached.
As for how many times we changed the wheels, we never changed the omnis, and only replaced two of the banebot wheels throughout our entire competition season.