Where can we find good pneumatic wheels?

[EricH]

It should also be noted that:
1) Said wheel does need some hub modifications to use in FRC--the stock hub configuration has a hard time with attaching a sprocket.
2) Spare tires are a must if you do drive practice. A lot of those tires showed red (and inner lining) by the end of the season, and the batteries were constantly on the charger due to the amount of drive practice put on them.

[topgun]

Originally Posted by EricH

It should also be noted that:
1) Said wheel does need some hub modifications to use in FRC--the stock hub configuration has a hard time with attaching a sprocket.

Any pictures or drawings of how you did the hub modification? Did you actually modify the hub or fabricate an adapter between the hub and the sprocket.

[EricH]

Originally Posted by topgun

Any pictures or drawings of how you did the hub modification? Did you actually modify the hub or fabricate an adapter between the hub and the sprocket.

I forget how we did it in 2005, but the hub itself is 3-4 pieces. 2 of them are rims, sandwiched between hub pieces. The hub pieces get modified/replaced.

In 2006-2008, we used a custom adapter to hold the rims in place, and a spacer to keep the sprockets separate. I don't have plans or pictures readily available; ShaneP might have some better ones.

Oh, and using 6 of these wheels on a 6WD is asking for turning problems, even with a dropped center wheel.

[topgun]

Originally Posted by EricH

Oh, and using 6 of these wheels on a 6WD is asking for turning problems, even with a dropped center wheel.

What kind of turning problems? Slow, or bumping, or fuse blowing?

Or are you saying you don't use 6 of these wheels on a 6WD?

How do you overcome the turning problems?

[Hawiian Cadder]

http://www.radioflyer.com/22w-0642699.html?sid=5

with slight modification these work pretty well. they are light and durable as well.

in past years my team has mad an axle with a disk on it, then the radio flyer wheel is bolted to the disk in a similar manner as a car wheel.

[Jeffy]

Can anyone supply some information for me about the mcmaster wheels mentioned by 330. Part number: 2717T51 We are looking at these as a high CoF option for our drivetrain this year.

What I am looking for:
Mostly design of the stock hub/rim. Searching the web eludes to that all pneumatic casters are very similar, if not the same hub design. I was unable to find a model, or drawing.
I'm curious on what the size of the 4 bolt circle is.
Also, I am looking for the size and length of the shaft part of the wheel. (I do not mean interior dimension, but outside dimension so that you could machine a hub and and insert it over.)

Thanks in advance.

[EricH]

Rims are Al, curved, with the 4-hole pattern. I think the hole pattern was on a 1.5" radius circle, but I'm not quite sure.

Not sure on shaft portion, but I do know that 330 did custom hubs. They might still have the CAD around. I'm not sure I have access to the repository anymore; you'd be better off asking one of the other 330 members.

[Ken Streeter]

Can one of the teams that used the McMaster wheel (2717T51) last year please post the tire information for the tires you used for that wheel?

I'm looking to find out the manufacturer and model number for that tire. Thanks!!!


Team 1519 has had great success in the past using various pneumatic Skyway wheels. See http://www.skywaywheels.com/ Their wheels are available with various semi-custom hubs, see http://skywaywheels.com/products/hubs/index.html Discounting is available for FIRST teams, as described at http://skywaywheels.com/usfirst.htm

Last year, we used the Skyway WHL-428 (a 9"x2" pneumatic) on the front of our robot. Photos can be seen at http://www.chiefdelphi.com/media/photos/35102 and http://www.chiefdelphi.com/media/photos/35535. The tires on these wheels were an Innova IA-2817-4 with a size of 2.80/2.50-4. These had great grip and were extremely rugged.

[Nathan Streeter]

Originally Posted by Ken Streeter

Last year, we used the Skyway WHL-428 (a 9"x2" pneumatic) on the front of our robot. Photos can be seen at http://www.chiefdelphi.com/media/photos/35102 and http://www.chiefdelphi.com/media/photos/35535. The tires on these wheels were an Innova IA-2817-4 with a size of 2.80/2.50-4. These had great grip and were extremely rugged.

These tires have phenomenal traction and excellent wear! We used them all season, with heavy wear at 2 regionals + championships + IRI, and half a dozen one day off-seasons. We played into Saturday afternoon at all the competitions, but we used our twin for practice during the season, so it didn't see as much practice time. The only downsides...

They're extremely wide (in reality, they're about 3"+ at the hub)
They're quite heavy (~2 pounds each, I think)
They're 9"... good for some applications, not-so-good for many others!

We're looking at doing a 6WD this year so unsurprisingly we're looking for smaller wheels! :-) Thanks for all the links - I'm tempted by the 6" pneumatics from McMaster! Dropped center with roughtop or wedgetop tread on the corners, most likely...

[ChrisH]

Originally Posted by topgun

What kind of turning problems? Slow, or bumping, or fuse blowing?

Or are you saying you don't use 6 of these wheels on a 6WD?

How do you overcome the turning problems?

Major bumping, several inches in the air bumping. Pneumatic tires bounce really well once you get them started, and if you keep going they bounce higher. If we're using 6 wheel drive we'll probably have plaction wheels on the corners. They slide sideways pretty well without giving up much in the way of fore-aft traction.

[Yalib]

Can enyone help us compare the wheels that were given above with some advanteges and disadvanteges about each? i have to say the mbs wheels looks really high quality...

[EricH]

The McMaster ones are high-traction. Give us 2 of those as our center wheels, and we'll able to hold our own in a pushing match if needed. 4, and we'rr a bit better. They wear well, too; when you see the red, pull out the spares, but you've got a few more matches. One set could last an entire event, eliminations included, and be usable in practice later. The cost is about the same, $20 US/wheel, but McMaster is known for fast shipping if they're near your area (and willing to deal with you).

I don't know about the MBS wheels in terms of traction and wear; mountainboards aren't exactly designed for light use, though. (And they're not designed to be self-powered...)

Looking at the Radio Flyer wheels, they're more expensive (over $25/wheel) than either of the other two. Again, no real experience there.

The biggest problem with all of them is that they will need modification to work with a drive system. A sprocket needs to be attached somehow. See the explanations earlier in the thread.

If it's track record you want, McMaster wheels have a lot of regional and Championship wins, and I don't know of a single failure other than tread wear, which everybody has. I don't know about the other types mentioned.

[Chris is me]

Originally Posted by EricH

I don't know about the MBS wheels in terms of traction and wear; mountainboards aren't exactly designed for light use, though. (And they're not designed to be self-powered...)

For what it's worth, neither are the McMaster wheels... They're for casters, no?

Mountain board wheels are high traction, but that's partly because they're designed for dirt and grass. Thus the wheels are pneumatic to increase their contact patch, since on loose non-carpet surfaces your surface area comes into play (dynamic friction due to deforming surface). So how they perform on carpet remains to be seen.

Do keep in mind traction for non driven wheels may not be the #1 priority. Scooter and inline racing wheels are a perfect size for first (90-125mm) but have a polyurethane tread with a hard 80-95A durometer to decrease wear and to allow for controlled skids.

[EricH]

Originally Posted by Chris is me

For what it's worth, neither are the McMaster wheels... They're for casters, no?

True. Radio Flyer wheels have the same problem.

[Ian Curtis]

Originally Posted by EricH

The McMaster ones are high-traction. Give us 2 of those as our center wheels, and we'll able to hold our own in a pushing match if needed. 4, and we'rr a bit better. They wear well, too; when you see the red, pull out the spares, but you've got a few more matches. One set could last an entire event, eliminations included, and be usable in practice later. The cost is about the same, $20 US/wheel, but McMaster is known for fast shipping if they're near your area (and willing to deal with you).

I don't know about the MBS wheels in terms of traction and wear; mountainboards aren't exactly designed for light use, though. (And they're not designed to be self-powered...)

1276 used pneumatic wheels and hubs intended for mountainboards in 2005 for our two powered rear wheels. The front two were omniwheel casters. We played in the vicinity of 10 matches (qualifying plus 3 elimination rounds), had a week of driver practice and two more years of abuse driving it on just about everything as a defender for driver practice and demo bot. They stood up just fine. I don't remember the vendor, it was just some mountainboard shop we found online.

You can barely see the top of one in the lower right.

One of the reasons we gave up on pneumatic wheels was they make driving straight (especially in autonomous) a really big pain in the butt. We found how straight we drove could be impacted hugely by a relatively small difference in tire pressure. We found it much simpler to drive in a relatively straight line once we made the switch to solid wheels. YMMV, or you might actually finish on time so you have time to test better code!