Team 133 is potentially going to be working on an offseason project/outreach robot and I was wondering what size/type of wheel would work best for various terrain, namely grass, dirt, and tar.
I think the 8" andymark pneumatic wheels are definitely a safe bet
Yes. Pneumatic wheels would be my first choice.
My second choice is carpet.
It doesn’t roll very well, but it will keep dirt off your existing wheels.
Dave
+1. http://www.andymark.com/8-inch-pneumatic-wheel-p/am-0970.htm
Carpet on wheels in place of tread? Interesting, I’ve never thought of trying that before…
If you want something that is easy to mount to an FRC style drive without modifications than for the given environment andymarks pneumatic wheels or wcp pneumatic wheels would be the best option. If your willing to make your own hubs or modify an existing one in some way then look at surpluscenters stock of pneumatic wheels. They have many different sizes usually for not much money.
If you’re going to be running the robot on outside surfaces such as grass and dirt, you’re probably going to not want to use stuff you’d use in a build season. WCP recently developed a hub adapter (WCP-0100) for their wheels that allow 8’’ wheels to be used, or, as the owner of WCP said here you can use a 200mm tire instead of a true 8’’ tire. That way you can get your stuff dirty without having to worry about using it on a real robot later.
Actually put the carpet down first. Then add robot and stir.
Dave
I mean after seeing people interpret it as “wrap your wheels in carpet,” I’m interested to see how well that would work…
I’d go check out your local hardware store and check out what they have for pneumatic wheels, and or plastic lawn mower wheels.
For outdoors, the bigger the wheel the better.
For Stronghold, we used six Harbor Freight 10" pneumatic wheels. Welded a longer center tube with a washer that could bolt a sprocket to it. Was amazing. And the wheels were only six bucks, but yes, the welding was tedious.
We’ve used this type of drivetrain on a t-shirt shooter too.
Rino drive is good for most non carpet conditions. AM makes a “off road” version too. It will give you more ground clearance. But or will cost you unless you can manufacturer a clone like we did for 2016. If you want pics pm me. Ours is not the off road type. Search my username in cd media pictures to get a idea
We used these on our 2016 robot.
About two weeks ago we were at an outreach event with one of our team partners. There was a huge field next to where we were and so we decided to take the robot for a spin out there. It worked amazingly well, and we even had some kids chasing after it. (The OM5P-AN radios have a good range in an open field, about 350 ft.)
The only drawbacks are that you have to design your robot around them and that getting the hubs on them takes some time to figure out. That was one of the few things I wasn’t a part of last year and it took that team almost a full 5-hour Saturday session to figure it out and get it done (we used am-2234 pulleys on them).
We ran them like a tank with 12.75:1 Toughbox Minis, 2 wheels/side, 2 CIMs/TB.
Also, overinflating the wheels (past 4 psi) voids the warranty, but it allows you to get some sweet jumps (especially over the rock wall).
If you want a real track chassis the tracks on our were better than anything else we saw, homemade or store bought
They’re huge, they’re cheap, and you can connect to the bolt pattern pretty easily.
Our robot from 2016 was extremely good at driving on dirt, grass, concrete, and bricks. It seemed to have no problem turning and seemed to not take much wear for the effort. If you are doing this testing on school or public grounds I would recommend not going too fast, turning at high speeds tore up any grass in it’s way. Warning aside, it was a six CIM independently driven drivetrain driving 9" pneumatic wheels. The gear ratio was 14:50:14:50, with an estimated 13.3 feet per second.