Re: AndyMark Plaction Wheels
 

A 1/8" rivet will NOT fit into a 1/8" hole. You need to drill the hole using a #30 drill bit.

Re: AndyMark Plaction Wheels
 

Not sure what kind of drill you are using but I have been putting 1/8 rivets into 1/8 holes and 3/16 rivets into 3/16 holes for as long as pop rivets have been available.
Bruce

Re: AndyMark Plaction Wheels
 

our team tried to use the plaction wheels, and we also had the same problem! we ended up changing wheels though because our turning maneuverability was poor

Re: AndyMark Plaction Wheels
 

We are running a chain driven 4x 8" -wheeled tank setup with dual-CIMed AM supershifter gearboxes on each side. As we entered the semi-finals of the Midwest Regional, we were losing staples and had to super glue the tread ends of one wheel. Then later in the semifinal, after not paying enough attention as to why only one chain was getting progressively looser after each match, we ripped a sprocket off that wheel, shearing bolts and shattering the sprocket, plus breaking the chain at the master link. Even though we had all six screws, they were low grade screws and several were slightly short and did not fully engage the nylon inside the Nylock nuts.

Because we have the dual sprockets on out gearboxes, with one chain to each wheel, our two rear sprockets are spaced away from the side of the wheel to line up properly with the dual sprocket of the gearbox. These spacers were not done right, and allowed too much flexing of the screws which finally worked themselves loose. This was the cause of the chain loosening, and by not zeroing in on the cause the problem went to self destruct stage.
We have now replaced all our KOP sprockets with new 22-tooth ones that do not have the six radial slots in them. We have replaced all our chains with 100% riveted chain (no master link & 50% higher working tension)). We have 1/2" diameter precision nylon spacers between sprocket and wheels. Screw heads are allen socketed (not slotted) so they can be seriously tightened. We now use Locktite blue on the the Nylock threads too.
As for tread to wheel attachment, after roughing up the plastic surface with abrasive paper, we are gluing the Roughtop treads onto the plastic wheels with GOOP Shoe Goo urethane adhesive. We use large hose clamps to compress tread material against the wheel overnight. This produces an almost inseparable bond.
We also decided to have spare upgraded wheels with sprockets mounted ready to go in case of failure. Handling the torque output of this drive setup demands that all components be made with top notch materials.

-Dick Ledford

Re: AndyMark Plaction Wheels
 

Has anyone else had problems with cracking of this wheel? We lost an entire segment of the rim, spoke to spoke, on one wheel yesterday and had to splint cracks in another. This appears to be happening when going over bump. Cracks seem to form on outside of facing side of wheel first and then propagate through wheel. Since the robot never comes down off of the bump completely square to the floor, the outside of one rim takes more of the impact. This is what we think is causing wheel to crack. At least that is what appears to be happening.

Re: AndyMark Plaction Wheels
 

Our 6" plaction wheels started to exhibit cracking in the spokes almost immediately after we started going over bumps at competition weight.

Mistakenly, I ignored the crack in our competition robot wheel, as it was only on one half of one spoke. In semifinal match 1 at the Seattle regional, the wheel shattered into three pieces, splitting at each of the three bolts we were using to attach the drive sprocket.

We were able to swap in a wheel after using our time out and run semifinal 2, though because it was our front wheel, we couldn't make it over the bumps. We ran chain again before the finals and were back in full working order.

As mentioned earlier in this thread, we'd now recommend that all teams use all 6 bolt holes on these wheels. :)

Re: AndyMark Plaction Wheels
 

It seems like everyone is using the Andymark wheels with the standard 1" wide tread, but did anyone besides teams 3193 and 48 use PVC spacers to widen the 6"-diameter wheels to 2"? We had success with them using black nitrile treads from McMaster in our 8-wheel drive, but we too had issues with the tread coming off when we tried using staples like the original AM treads. Two 1/8" rivets (1/2" long) drilled into the PVC spacer worked great.

However, we found another issue: when mounting sprockets, you have to watch how hard you tighten the bolts on the hubs, as there is no support between the hubs because of the spacer. We found a couple cracked spokes, and we found one wheel had all six spokes one one side broken through after our last quarter-final match in Cleveland. If...I mean when we use these again, we'll definitely look to add spacers at the center of the wheel so that the hubs are not squeezed and stress isn't transferred to the spokes.

Re: AndyMark Plaction Wheels
 

i'm surprised that the engineers at andymark aren't fixing this sort of an issue for the current production. it seems like something a company should do if many customers are having the same issue

Re: AndyMark Plaction Wheels
 

These wheels have not been tested in an environment as abusive as this year's game. And it's not just these wheels breaking. teams are breaking wheels of many different types as well as axles, frames, and many other robot parts.

Andy and Mark are busy people, I find it remarkable that they manage to do as much as they do during competition season. I expect they will take a look at the Plaction wheel in the offseason and decide if it should be improved or if the issues are caused by abuse that the wheel just isn't, and won't be, designed for.

Re: AndyMark Plaction Wheels
 

AM does customer surveys after every season. These wheels lasted in all our applications without breaking.

Re: AndyMark Plaction Wheels
 

Despite damages to some of our plaction wheels this season, I'll take it over anything else out there.
Its a replica of what we normally machined in the past using aluminum.
Due to time constraints this season, we elected to go with these. The simple fact that you can use either wedgetop or roughtop is awesome. It is a much cheaper solution and saves us time from making our own.
No one with mecanum, omnis and other types of wheels/tread has outpushed yet in our homezone. If anything, its other teams complaining about us in the act of trying to score goals.
Thank........you.............AndyMark.;)

Re: AndyMark Plaction Wheels
 

My team had a sprocket failure in our drive at CT, and the bolts sheared before the Plactions sustained any damage whatsoever. I was seriously impressed. The Plactions are versatile, durable, cheap wheels that are better than any custom solution my team could have done. Unless we can make something lighter I don't see myself ever using anything else.

Re: AndyMark Plaction Wheels
 

Go to this page and you will see several different kind of wheels that AndyMark has offered to the customers. Depending on the applications, the customers should choose from the collection.

We have a 8wd (all plaction wheels). We riveted the treads on the wheels and haven't had any of them come off. We were in 12 matches in Cleveland and the robot went over the bump at least twice every match (when coming down the impact was very high). I haven't seen a crack yet, but I forget to check again before we packed up the robot for Atlanta, so that will be the first thing on my to do list. Overall, I like the wheels; it hasn't given us any problem so far. Thank you AndyMark.

Re: AndyMark Plaction Wheels
 

Team 1261 uses four 6-inch plaction wheels on the robot. We have yet to encounter any problems of the tread slipping on the wheel. We have not riveted to the tread to the wheel either. The only thing that has happened to us is the screws holding the sprockets onto the wheels became bent, and that was our fault for not tightening them enough. They have survived two regionals and we have yet to see any sort of physical damage on the wheel.