Re: Help!!..wheels?
 

We press-fit the colsons on the AM hubs and put three 10-32's through the hub plate to secure them.

Works great and takes like only a couple minutes to assemble.

Re: Help!!..wheels?
 

I agree with you here, for wedgetop. Blue Nitrile Roughtop is among the most durable tread materials I've used. Over the 2007 and 2008 season, using the robot for both competition and demos, we NEVER changed our tread on each bot. Never had a problem with roughtop wearing. Wedgetop, on the other hand....

Nitrile rocks. Never had a bad experience with it. Just lay it against an AM wheel that's been stripped of the polyurethane, drill some holes and slap a few pop rivets in. It's janky, but it WORKS.

Yeah, weight distribution is key. I've mostly used roughtop on our 6 wheels, and had no problems there. The closest we got to wearing tread out was on our 2005 Crab Drive, for Triple Play, and that wasn't bad enough for the bot to be at a disadvantage.

Seriously, if you do your attaching right, you can't go wrong with Blue Nitrile (assuming FIRST keeps the carpet....).

Re: Help!!..wheels?
 

If FIRST doesn't stay with it, go with red linatax.

Re: Help!!..wheels?
 

Red Linatex technically has a higher coefficient of friction than Blue Nitrile Rughtop, on FRC carpet. So if a team has the money, go for Linatex every year. It wears insanely well, and is grippy like no other. Only problem is the cost... It's MUCH cheaper to go with Blue Nitrile, at least from the suppliers I've found...

Re: Help!!..wheels?
 

Craig, I was going for the icy floor! Lol.

Re: Help!!..wheels?
 

That would be fun.... Though I'd be a fan of carpet with either a fence or a BIG ramp in the middle... Stack attack style, y'know?


On the topic of wheels, keeping cost under consideration from the beginning is key. If you don't design for your end requirements, not too much point in what you're doing. Billfred brought up some GREAT suggestions. He's cool, so his posts deserve reading extra carefully.

Re: Help!!..wheels?
 

We've used IFI wheels in the past with decent results but the tread is a pain to replace. This year we are looking at the AndyMark Plaction wheels, basically kit wheels with a system for easily using conveyor tread material, and cheap too!

Re: Help!!..wheels?
 

When i went to AndyMark this off-season Andy said that he was new traction for his traction wheels ( to complement his new wheels ) so just talk to andy about alsohe said that his new treads should last 2 regional or even 3 :yikes: .

Re: Help!!..wheels?
 

I'll also throw support to the Colson wheels for three main reasons: durability, cost, and fabrication time necessary.

Durability: There are a lot of offseason competitions in the Northeast every year. Couple that onto the official scrimmage in February, and two official FRC competitions, and one of 228's robots can see eight to nine competitions a year. In New England.

The hard defense played up here really wears down Roughtop fast. We've been able to get an entire season out of a single application of Roughtop before, but after the first competition it already lost a considerable amount of traction. Colson wheels on the other hand (the 5"x2" Performa ones to be exact), went through eight competitions this past year without any noticeable change in performance.

Cost: At between $4 and $10, you will be hard pressed to find better wheels elsewhere for this cost.

Fabrication Time: About ten minutes per wheel, depending on how you do it. The approach 228 uses is to take aluminum rod, turn down the outside to a diameter slightly oversize past the diameter of Colson wheel hole, bore out the inside to axle diameter, knurl the outside of aluminum rod, use cutoff tool to cut off about 1-1.5" piece, use arbor press to broach hole with keyway, and then use arbor press to press aluminum rod insert into the Colson wheel. You now have a completed live-axle Colson wheel.



If dead axles is more your thing, then take one of the thinner 7/8" wide Colson wheels, put it on a rotary table, and drill three-six holes through the wheel, which you can then mount sprockets to.

Sure, they aren't as pretty necessarily as custom machined wheels, but at a final cost of about $10 a piece, ten minutes of machining time, and a sky-high reliability, they can't really be beat. And from an engineering perspective, that's beautiful.

Re: Help!!..wheels?
 

inlflateable wheels, dont wear down very easily......

Re: Help!!..wheels?
 

:) We have also used Skyway wheels, which were part of the KOP in past years. We have doubled them for more traction, and applied belt material to them as well. You can order them with precision 7/8 OD bearings, 3/8 ID bores installed, which really makes them a good deal. I don't recommend the
.906 bearing option, as they are not very good quality.

Re: Help!!..wheels?
 

Depends. 330 goes through a set of center wheels per event, roughly. They also drive the robot to its limits or until they get kicked off the practice field. (The practice robot? Double that.) Those are pneumatic casters.

The other year we used pneumatics was 2004, and we spent most of the time on the bar, so the wheels didn't get a lot of wear.

Re: Help!!..wheels?
 

we've only ever used them for 4wd....why would the middle wheels wear faster than the oustide one? it seems like the corner ones would have more scrubbing on the floor surface when turning

Re: Help!!..wheels?
 

I never said the middle ones wear faster than the outside ones. Guess what else gets replaced at an average rate of once per event?

Re: Help!!..wheels?
 

We're looking at using 1/2" cantilevered dead axles again this year, and I notice that Colson wheels are available with a 1/2" bore bearing or bushing, although it's not the most common hole size for them. Instead of using a rotary table, maybe we could put a bearing into a sprocket, bolt it to the wheel with a 1/2" bolt, and use the holes in the sprocket as a template for drilling the holes in the wheel, bolt the sprocket to the wheel with the 3 or 6 small bolts, and then leave the bearing in the sprocket to keep the sprocket concentric with the axle on the robot.

There seem to be several different types of tread avaiable, do you have experience with some of the different ones, and recommendations?