Re: What kind of wheels do you use?
 

Does that mean the wheels turn freely on the shaft? And that the shaft is stationary?

Re: What kind of wheels do you use?
 

We use custom made, open cell skyway wheels. We then make diamond shape cuts on them so we have enough traction on the field.

Re: What kind of wheels do you use?
 

Correct.

Bearings are pressed into the hubs, and a sprocket bolted to the side, with the shaft mounted through two blocks, rather than having the shaft mounted through pillow blocks, and then the sprocket bolted to the shaft, with the wheels fixed.

Re: What kind of wheels do you use?
 

What do you people think about
the Multidirectional wheels or
Omni Wheels

Re: What kind of wheels do you use?
 

Omni wheels are great! If you want lots of traction while using them, then you must design them using the right materials.

In the 2003 and 2004 we built a 4 wheel drive to 2 wheel drive conversion for our robots.
We built these conversion mechanisms so we had better maneuverability and so it was easier to turn.

This year we decided against using them because it took time to deploy them.

So we used two pneumatic tires in the front and two omni wheels in the back.

Re: What kind of wheels do you use?
 

Go-Cart tires sound somewhat familiar...
They have REALLY good grip (no one was able to push us once we fixed our limit switch). I remember at VCU that we held 345 (Blarg!) and all they did was spin tires and burned the carpet.

Re: What kind of wheels do you use?
 

I'm more than willing to bet that our team (1501) had some of the cheapest wheels. We used 4" PVC pipe covered in conveyor belt material. The ends were PVC caps with 6 blind nuts for mounting the drive gear.

Re: What kind of wheels do you use?
 

I had kicked around this concept in my head, but I wasn't sure how up to the task the pipe would be. How did they hold up?

Re: What kind of wheels do you use?
 

We use an wheel typically used in elevators to keep the car on track, with a modified rubber compound. They are some of the grippiest wheels you can get for the carpet, but I don't know how'd they be against those racing tires!
Heres an example: Two years ago (using the same wheels and a 120lb bot), we pulled a minivan (Caravan?) on worn smooth pavement with no problems or slip.

Re: What kind of wheels do you use?
 

330 typically uses the kit Skyway wheels, but adds belting. This year, however, we used four of the six-inch Skyways and ground almost all of the tread off so they'd slide when we turned, then used some heavy tires (I don't know where we got them) in the center, one on each side.

Re: What kind of wheels do you use?
 

For the years I have been on the team, I think we've used 6-6.25in diameter, 2in wide (80, but it might be 60 durometer solid rubber tires). Most years they've had treads, but for FIRST Frenzy they were smooth.


On a side note, I don't think we've ever tried to pull a vehicle with our robot...but :D , There's a whole season ahead of me and a spiffy idea to try out...was the van in or out of gear at the time of the pull?

Re: What kind of wheels do you use?
 

I'm guessing it was in neutral. plenty of teams have done this before, it's really not all that hard, actually. Once you get it started, it's pretty easy.

It'd be darn near imossible to pull a car that was in gear. I doubt any FIRST robot ever built would be able to. The only one that would have any chance would be 71's 2002 bot, with like 5 people piled on top.

Re: What kind of wheels do you use?
 

I'd imagine it was. I was just an onlooker, not actually involved at the time (still in fll). I was just amazed that it didn't slip the wheels when starting. And it wasn't a particularly slow start. I guess some decent pnuematic tires would do a good job too.

Re: What kind of wheels do you use?
 

We had 6 inch rear wheels made by an offroad skateboarding company. They worked great but they don't have an amazing life span. We noticed today that they are almost grip free but they did work great for 1 regional and 1 off season event. For front wheels we had 4 inch omnis that were like two single sets of omni's put together then offset. I'll look around for the company website.

Re: What kind of wheels do you use?
 

we used 2 8in trick wheels (omnis) from andimark.biz on front and then we took some heavy duty casters and riped the wheels off them for the back