pic: Completed Mecanum Module

wheel
drivetrain
gearbox
transmission
frc488
mecanum
xbot
omnidirectional

#1



The completed module comes in at 9 lbs., just about everything included except for the suspension dampener.

The gearbox needs working in – without lubrication, it’s quite loud – but it’s otherwise really clean. The CIM pinion threw its key out because there’s nothing holding it on right now. We’ll track down some retaining washers this week. :slight_smile:

We’re making a big push to get this chassis up and running by the end of the weekend. We’ve worked out all of the problems in this single module, so the remaining three should go together quickly from what we’ve learned.


#2

To hold the CIM pinions and keys on, Loctite 680 retianing compound works nicely. It takes a fair amount of heat to remove, but otherwise is very simple and effective.


#3

I’ll look to see if we have some of that lying around somewhere as well. Thanks for the suggestion.

We’d been planning on using the same system of retaining the pinions as on the kit transmissions. The team is a bit averse to using Loctite on anything because of the large amount of plastic we typically have on the machine. Instead, we use lock nuts.


#4

Since you designed the drivetrain with 4 individual modules, why did you choose to keep the chain reduction in there instead of driving it directly with gears? Sorry if I missed a previous post where you answered this question. I am not saying one way is better, just wondering the reasoning for your this particular choice.


#5

What we did last year for holding the pinions on was file a small grove in the motor shaft and use an e-clip. Since you have a key way, and a setscrew it doesn’t take much to hold the pinion on the motor shaft. The trick with this is to cut the grove to match a size of eclip.


#6

that’s freaking SHWEEEEEET!!!

I totally want to see you drive that before competition! Possibly up some stairs? at your discretion…

Nice work, and good job!


#7

More than anything else, the use of chain allows us some ability to change the final ratio more easily than is possible with gears alone. Once we have more experience with the drivetrain and how it operates, I’d consider designing an integrated gearbox and eliminating the chain and sprockets altogether.


#8

Looks beastly!
Hmm…mecanums are getting popular. I wonder what the next big thing will be. Once we’ve run out of next big things, then this won’t be so fun anymore. Hope that never happens!


#9

Madison those look splendid. Chain reduces a lot of weight instead of having all gears thats probably another reason for her using chain. Judging by the looks of that module it’s going to be a pretty bulky chassis. Madison question for you have you changed the chassis design from the drawing you posted about a month ago with the completed chassis design?


#10

I haven’t changed anything significant about the design at all since I posted CAD drawings.

The completed module is 9 lbs. and the chassis it rides in is about 5.5 lbs, so without electronics, we’re looking at a completed drivetrain for about 42 lbs. It’s a bit heavier than I typically try to make drive trains, but not by very much. The wheels are individually heavier than all six of the wheels we normally run on our more traditional chassis designs combined.