114: how we roll:
We ran this drive train far too hard, and it never broke. Rolling on Custom CNC’d 4 inch aluminum wheels, with a single bolt tightening tensioner system, we had good enough pushing power to hold our own. Then we shifted into high speed, and were nigh uncatchable at 15 fps. Look for an improvement on this gearbox hooked up to something even crazier next year!
Single bolt tensioner system? Sounds interesting, how’d you do that? and what’s the CoF of that nitrile stuff?
I like the blue roughtop stuff. We use it. Drives pretty nice. And about 45 matches worth of driving and it is holdng up just fine. Not even close to getting worn out.
Just curious, why did you chose to go to dead axles? (or so it appears).
where did you get that blue nitrile tread?
-Alex
I’d like to know the CoF on that too. Any chance on a paper with the gearbox? Nice job on a sweet drive.
Nitrile rough-top has essentially equivalent CoF to rubber rough-top, both about 1.3. 116 purchased our nitrile from McMaster, and I’d assume 114 did as well (only source I know of).
Rollin of fo’s thats totally sick baller yo! Are they chrome? Next year we are thinking of getting anything that can be chrome dipped, chrome dipped. So we can have a “bling bling” robot… We are also working on a ball bearing spinner idea… We will tell you how that goes…
impressive, my team needs to learn how to build a drive train.
Chris
Our outer shafts are mounted in two bearing blocks inside a milled out pocket in the 2x1 frame bars, and the bearing blocks are linked via a plate on standoffs. From a plate at the front of the drivetrain, a bolt goes back to the linking plate, and can be tightened to pull the chain. Look here: http://www.chiefdelphi.com/media/photos/27585
You can kinda see the tensioner at the bottom corner.
The axles are live, with an eighth inch key in them. They sit in bearing blocks that are pulled to tension the sytem.
McMaster. It’s blue nitrile, food grade conveyor. We love the stuff.
I’m not too good at making papers. However, these transmissions may soon be sold from Trossen Robotics, in a partnership with Outback Manufacturing. Keep an eye out.
It’s actually not, just on the same page as the food grade conveyors. 
The nitrile is incline belting.
Bah, same difference. We love INCLINE BELTING then…
But yeah, it only slightly wore down, and only on the middle wheels. I have a feeling the wear was because of our ability to score extremely well, and so we were targeted with heavy defense the whole time…
How often did you use high gear?
Having 114 on our Alliance at Davis was awesome, though. 675 (us) and 2159 (Robopirates) played Defense while Eaglestrike had fun with the rack.
Our driver didn’t use it nearly as much as he could have. However, there were a couple notable sprints where it came in handy. I’m working on an idea to make the driver take advantage of it more next year.
Just a few more questions,
Whats the weight of the gearbox alone?
Whats the weight of the entire drive base (including wheels, chain, gearboxes, motors, electronics)?
Why did you choose to go live axle without the benefit of being able to quickly change wheels (your outer side plate looks welded on)?
Thanks!
Weight of the gearbox alone: 9 pounds with motors and pneumatics.
Weight of the entire drive base: somewhere around 40 pounds.
We have the ability to pull off that outer bar by undoing 4 bolts (you can’t see them in this shot), and then it’s simple to pull and swap wheels, gearboxes, and wheel modules. It was really a great system, mostly because I never needed to maintenance it.
I had my doubts as to if you guys could get up on our platforms with your small wheels…
but I must say that in Davis your drive train REALLY proved itself to me. it got right up and your drive team was excellent, only needing a few seconds to do it 
Plus, those blue wheels kind of grew on me 
is it any coinidence that you, 604, 254 and 968 all chose 4" wheels the same year? I know 254 has talked with 604 about wheels before, have you as well?
Our wheels are done in an entirely different style than 254/968. And we don’t really communicate, so no relation. Theirs is a two piece bolt together setup, where ours are a one piece sold object. In the past I’ve noticed less trouble with our design over the two piece.
1072 would like to say that they like the way 114 rolls