Where can we find good pneumatic wheels?
 

Me and my team trying to learn about good and diffrent drivetrains than those we used in the past few years and we want to see more about pneumatic wheels (for example 1114 wheels at 2010)

so those anybody can help us to find good pneumatic wheels?

Re: Where can we find good pneumatic wheels?
 

50% of the time that 330 used mcmaster 2717T51, we went to Einstein. Your mileage may vary.

Re: Where can we find good pneumatic wheels?
 

"You must spread some Reputation around before giving it to Joe Ross again."

That's an awesome stat Joe.

Re: Where can we find good pneumatic wheels?
 

Wow, just wow!

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

I'm also a member of 2630,
We checked out the mcmaster wheel and it looks really good, Do you know if this wheel has a tenon slot?

Re: Where can we find good pneumatic wheels?
 

You mean a keyway? Not stock--you'll have to modify the hub. It's designed to be used as a caster (unpowered), so any powered use needs modification.

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

I got yelled at when i stated those sort of statistics, something about sample size, only mine was even more restricted than yours,

"6wd swerves have a 100% chance of einstein historically" :p

on topic:

I wish someone made a good 4" pneumatic wheel

Re: Where can we find good pneumatic wheels?
 

The pneumatic tires on 494, 70, (and of course 469 on Einstein this year)were from MBS Mountainboards. They were an 8" knobby black rubber tube tire with a glass filled nylon hub. They are intended to be used on, get this, mountain boards.

We've used the same tires / hubs several years and never had a flat or a broken hub. I think these are far superior to any wheel/tire made for FIRST robots. Of course the tread will wear down, but we've been able to get through a season before we've completely destroyed a set.

MBS is located in Colorado Spring, CO. They have fair prices and good delivery. You'll see on their website a beautiful looking set of 6061-T6 aluminum hubs. I think this is what the fashionable robots will be wearing this season. Be a sport and wait till I order mine so they don't run out;)

http://www.mbs.com/

Jay

Re: Where can we find good pneumatic wheels?
 

Are those the same wheels 1114 used?

Re: Where can we find good pneumatic wheels?
 

Yes

Re: Where can we find good pneumatic wheels?
 

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?

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

Tell that to 70, 494, 469, 1114, and 2370 last year. 2370 actually used four pneumatic wheels in the long configuration - and turned just fine, somehow! I'll never understand that.

Re: Where can we find good pneumatic wheels?
 

Chris, I said 6 of those wheels in a 6WD drop, in 2006. We had trouble turning. I don't know if there is any video of the Arizona practice rounds around, but we bounced around a bit.

Solution: the front wheels, which were the primary off-ground wheels (6WD drop drives rock a bit, but can be weighted so one set or the other is mainly on the ground), were replaced with 6" Skyways. No more problems. In 2005 we used 6" Skyways on the corners; in 2007 we broke quite a few AM hubs on our rear wheels, but not so many on the front wheels. (We also caught a hub that had partially failed. Mark Koors happened to be the FTA at the event, so he got a wheel in the process of failing for analysis.) 2008 saw the revised AM 6" wheels on the corners.

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

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...

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

Can someone post a link to these wheels, I can't find them at all!

Thankss

Re: Where can we find good pneumatic wheels?
 

If everyone was havng problems with 6WD why was 1114 moving so easily with 8WD (2010). :confused:

Re: Where can we find good pneumatic wheels?
 

I would be very surprised if 1114 had all 8 wheels in the same plane. I bet that the center four wheels were dropped slightly, on the order of 1/8".

Re: Where can we find good pneumatic wheels?
 

And that made the wheelbase shorter than ours in 2006, where we had very little drop and 6 wheels. Long wheelbase=tougher turning, in general. This is why most 6WD robots have a dropped center wheel or omnis (or other low-friction wheels) on the corners. We didn't have nearly as much trouble after putting Skyways on the front corners.

Link to the McMaster wheels: go to the McMaster site and enter the part number into the search box. You'll get the page; the wheels are near the bottom. We used the gray treaded ones.

Re: Where can we find good pneumatic wheels?
 

We haven't used pneumatic wheels, but are thinking about it. We purchased two different 6" x 2" caster wheels from Grainger, p/n 1ZPE1 and 2RZJ3. We like the 1ZPE1 the best. It has a stronger hub and stickier, softer tire. Neither have great bearings. Each cost around $26.

Does anybody have experience with either of these, or know how they compare to the McMaster Carr 2717T51?

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

True. Radio Flyer wheels have the same problem.

Re: Where can we find good pneumatic wheels?
 

There's considerably less "bounce" in the 8WD we had compared to the 6WD that 330 employed with the same wheels. If construct a polygon between the centres of our wheels this year (or any standard 8WD) so get an upside down trapezoid. If you do the same with a 6WD you get a triangle resting on a vertex. Looking at these shapes, it's easy to see why one would have more rock, and thus more bounce.

Austin is correct. Here's a picture where our drop is depicted pretty clearly.

http://www.simbotics.org/resources/g...l/_3260103.jpg

Re: Where can we find good pneumatic wheels?
 

Wasn't just the rock, though. It was, literally, the bounce--the effect of high-traction wheels trying to turn. Same problem that caused someone to compare 4WD systems to Mexican jumping beans. Only, it was on a 6WD drop center. Lower traction at one end resulted in just the rock, and that's an issue that's easy to design around. The next two years, it was McMasters in the center and AndyMarks on the corners.

Re: Where can we find good pneumatic wheels?
 

I bet that depends largely on how inflated the wheels are. If you look at 1114's wheels, they're rather full-looking, so they probably are less likely to "dig in" while sliding and get stuck, causing stored / released energy in the form of bouncing.

Re: Where can we find good pneumatic wheels?
 

Didn't 70/494 have a crab drive in the wide direction?

Re: Where can we find good pneumatic wheels?
 

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! :)

Re: Where can we find good pneumatic wheels?
 

Yes.

Re: Where can we find good pneumatic wheels?
 

That's why we switched from pnuematic, we wanted to go to 4". We used to use 6" pnuematic on all our 4WD robots but when we went to 6WD we wanted smaller wheels.

FYI Our Custom wheels and tread have 100% chance of Einstien historically as well, and 50% chance of winning the Championship... (2006-08,2010)

Re: Where can we find good pneumatic wheels?
 

How did you (everyone who has used pneumatic wheels) select an inflation pressure? I would think traction, drag and turning would be fairly sensitive to that. What kind of pressure range could you tolerate with adequate performance? How often do you check it / adjust it?

Re: Where can we find good pneumatic wheels?
 

As far as pressure goes, it does make a decided difference.
We use 6" pneumatic tires on some robots. At full pressure the robot had more tendence to bounce. At lower pressures the grip was greater.
Too low and the tire might roll off the rim when it gets pushed sideways.

With the very small volume it can be an art to balancing the pressure in all tires. You need a pump with an integrated pressure gauge that disengages without letting even a smiggen of air out. Or you develop the skill required.

Re: Where can we find good pneumatic wheels?
 

Or you have a compressor with a regulator set to your desired pressure dedicated to inflating the tires.

Re: Where can we find good pneumatic wheels?
 

When we were in skid steer mode we had a wide aspect ratio. Traction was a consideration. As the tires wore down and got stickier it was harder to turn. In the off season we put tape on the front tires to reduce traction to make turning easier.

In the past we had long aspect ration bots with skid steer. In 2004,5 our tires were about 10-12" OD. They took lots of power to turn and were not " precise". On a high center of gravity machine there was quite a bit of bucking/tipping. We started out this way in 2006 and ended up with 2 omni wheels before we shipped.

On a low CG bot the long aspect ratio configuration was OK. In the future we'd most likely go with the 6 or 8 wheel design.

Jay

Re: Where can we find good pneumatic wheels?
 

Related thread about mounting sprockets, etc.

http://www.chiefdelphi.com/forums/sh...ad.php?t=88066

Re: Where can we find good pneumatic wheels?
 

We've used pneumatic tires in 2002 and several other years but those were the best tires/wheels yet. They were small so there was little bounce, yet great traction. The fact that they were pneumatic also lent itself to correct for leaning and imperfections in the carpeted surface--four wheels were always gripping. That was the year when 71 Hammond Beatty had the crawler which dragged the two goals with the opponents kicking and fighting to the other side of the field--so traction was paramount.

Here's a link. At the time everyone made their own hub mounting plates. The following year, FIRST came out with hubs in the KOP. Two large fender washers with the holes bored out with the use of standoffs sandwiched in between worked well for many teams.

http://www.skywaywheels.com/products/caster/index.html

Re: Where can we find good pneumatic wheels?
 

Skyway

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

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.

Re: Where can we find good pneumatic wheels?
 

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...