Ooooh.. So that's why it says Bayer on the side of AndyMark KOP wheels

[Elgin Clock]

http://www.bayerus.com/news/index.cf...750A56DB723CF7

Now it all makes sense. That's one of those things that when Andy showed the wheels to me at kickoff in NH, I just didn't think to really ask at the time, but was curious about.

Glad to see answers are always available when and where you least expect to find them. YAY Internet!!!

[RyanN]

We never used these wheels, but I would like to hear from the FIRST community on how these wheels worked for you. I like them personally because they have a tacky tread that seems to grip the carpet well and they are light weight. How are they holding up? Any problems or shortcomings to these wheels? I would like to know.

[Teched3]

-- If you go to the AndyMark site, they have CAD drawings of the wheel provided in the KOP. There is a cavity between the bearing support ring and the sprocket mounting bolt holes that is a weak point. We blew one out being defended (aka rammed) by other robots, and blew this ring out. We have reinforced this area with fiberglass strand and resin to fill this void. This only occurred on one of our center drive wheels, but this mod should take care of it. Great traction and light weight. As good as our modified wheelchair wheels that we have used in the past, and easier to mount sprockets. Hopefully, AndyMark will modify their mold to eliminate this problem for next year. By the way, we were still functional and competitive the rest of the match, and only noticed the damage when we got back to the pits. --

[ChrisH]

Originally Posted by RyanN

We never used these wheels, but I would like to hear from the FIRST community on how these wheels worked for you. I like them personally because they have a tacky tread that seems to grip the carpet well and they are light weight. How are they holding up? Any problems or shortcomings to these wheels? I would like to know.

The BeachBots are one of two teams that have reported breaking these wheels. We are not exactly sure what is happening, but we generally have a lot of drive time on them when they break, and I believe we've done it more than once.

But the traction characteristics are exactly what we want and they are cheap, so we just make sure to have extras on hand. We can swap one out during a 4 minute cool down period if we have to.

[lukevanoort]

They are generally very nice wheels, grippy, light, and most importantly (for us) cheap. We did have some issues though, we also broke them, in the same area as those previously posted. (Bearing holder) But, I suspect our breaks had more to do with spacers that weren't very accurately cut, because both of the breaks were in the same spot. (right rear, as I recall) We filled the void with epoxy + added a better spacer and they held up fine at our next regional. However, at our 2nd regional we usually had our partners run blocker to leave us free to score, so they didn't encounter lots of loads, hence the epoxy may or may not work as well for a defensive team as it did for us.

[Raul]

WildStang is using these wheels and we have broken a total of 7 now. The failure first appears as a crack on one or two spokes right next to the hub. I believe that this is occuring due to fatigue failure from continuous side loads.

How do we get so much side loading? Well, we have crab/swerve drive. Each time we make a quick change in directions from straight to side movements, it puts a heavy load due to momentum. Do this enough times and the wheels are being bent back and forth until they finally crack. Once a spoke cracks, the rest will soon follow.

So, I believe these wheels are great, except for crab/swerve drive applications. I want to beg Andy and Mark to beef up the spoke cross-section or use a more robust material.

Raul

[Andy Baker]

Originally Posted by Raul

So, I believe these wheels are great, except for crab/swerve drive applications. I want to beg Andy and Mark to beef up the spoke cross-section or use a more robust material.

Raul

You guys are all giving good input. Mark and I both appreciate it. If these wheels are used again (which, I dearly hope they are), we will definitely improve the areas where they are weak. All of these modifications involve taking material away on the mold, which is not extremely difficult to do.

Making the web thicker is not very difficult... but making the rib and body bigger around the bearing is a bit more tricky. Our molder suggested some of the features you see in order for the wheel to be released from the mold easier. We will use a greater taper angle, I think, to help beef it up while still allowing for part release.

We'll bring spares to Atlanta.

Andy B.

[Billfred]

Originally Posted by Andy Baker

You guys are all giving good input. Mark and I both appreciate it. If these wheels are used again (which, I dearly hope they are), we will definitely improve the areas where they are weak.

We ran them (hard!) all through Palmetto with no problems whatsoever, with a change from the original resin to roughtop and wedgetop, both for the higher CoF and for the slightly smaller diameter that let us move them a peg outward on the kit frame. The wheels handled it just fine to my knowledge, but I'll check when the team meets again to see about any cracking that may have appeared.

I did notice that the black nubs hidden underneath the resin were starting to show on some of the robots that ran them stock. I don't know any way to fix the problem (especially when you can just get a new wheel for $12), but it might start to get interesting around the Championship when some wheels go full-on with the alternating black and gray.

For my money, these wheels are great. The one thing I'd love to see is an option to get these wheels "in the nude", just to save a step in the molding process, but I'll take these just about any way they come.

[Madison]

We've had no trouble with the KoP wheels this season, but I'll look them over for signs of fatigue once we get to Atlanta. We have spares if they're needed, however, so I'm not anticipating any really bad things (tm) happening. We also have spare hubs and gears and who knows what else. I think we could open up a west coast distribution center for AndyMark products at this point.