AndyMark Plaction Wheels

[SteveGarward]

We hit this issue in the hour before shipping the robot. (We also sheared the bolts off one of the drive wheels and noticed the other drive wheels bolts were bent, but that's another story...).

We tried holding it on with tape just so we could practise prior to shipping, but it kept slipping out.

We had some spare wheels, so we changed them out at GSR prior to competition. These lasted a while (I think we were being careful) but by the end of Friday we had lot a tread again. We got it back together for Saturday, but lost the tread again in the next match.

Prior to crating it ready for Atlanta, we managed to get a couple of wheels ready, using contact glue on the tread AND rivets. Hopefully this will hold. Otherwise I'll either cry or just go home.

Ok, maybe not.. it's a long flight..

[Chris Fultz]

When you add screws or rivets, be sure to make them slightly off of the centerline of the wheel.

These wheels are molded plastic, and the seam is right in the center. By moving slightly off to each side, you are staying in stronger material.

Advice straight from the "manufacturer", so to speak.

[Jared Russell]

Same problem; same solution.

[thefro526]

Our Plaction wheels still have the standard staples from AM in them, and we haven't had any problems with them... yet.

*Scrambles to pack Rivet Gun and Rivets for next event*

[45Auto]

Obviously not many people on this thread read the AndyMark page on the Plaction wheels here:

http://andymark.biz/plactionwheel.html

Quote from the page:

Roughtop or Wedgetop conveyor belt material are used as replaceable treads on these wheels. For best use, install rivets into each end of the tread to insure the tread stays put under heavy usage.

First thing we did upon taking ours out of the box was to rivet the ends of the tread. Although we managed to break all of the bolts holding the sprocket onto one of the wheels in the semi-finals at the Bayou Regional, the wheel survived and we never had any problems with the tread.

Bayou Regional Champions with 1462 and 3362 - See you in Atlanta!

[MarkoRamius1086]

Those are amazing wheels! The traction and quality is superb, but ugh... We had the same problem with one of our wheels in the second to last match of the finals! We were going over the bump... and all of a sudden it stalled! You can see it on the youtube video... when we started over the bump the back tread came right off. I dont know if there is a channel that it popped out of... I didnt get a good look at it before we shipped it off. All I know is the moment our driver backed off of the bump, we had a tread lying on the field.

Seeing this thread I am certain we shall replace the stripped wheel with one from our prototype and then pop rivet all of them before the matches at NC. Has anyone pop-riveted the plaction wheels and has advice that could prove useful or critical? I saw the great post on not riveting on the centerline, thank you for that, but does anything else come up?

[Jared Russell]

Just make sure that the rivets you use are long enough to clear all of the way through the plastic.

[45Auto]

We used rivet washers under the head of the rivet and also against the plastic rim on the backside of the rivet to spread the load and keep the rivet head from pulling through the tread or the expanded side from pulling through the plastic rim. Two rivets at each end of the tread, NOT on the centerline.

[Alex Cormier]

Originally Posted by 45Auto

We used rivet washers under the head of the rivet and also against the plastic rim on the backside of the rivet to spread the load and keep the rivet head from pulling through the tread or the expanded side from pulling through the plastic rim. Two rivets at each end of the tread, NOT on the centerline.

I highly recommend at least 3 rivets. One on each end of the belting and add one on the opposite side of the wheel.

[MarkoRamius1086]

Our coach is thinking about riveting it in many different places. Two on each end of the tread, and then a zig-zag pattern to the other end. I am unfamiliar with the practice of riveting... can I assume we need to drill holes the same size of the rivet... and gun it in?

[Alex Cormier]

Originally Posted by MarkoRamius1086

Our coach is thinking about riveting it in many different places. Two on each end of the tread, and then a zig-zag pattern to the other end. I am unfamiliar with the practice of riveting... can I assume we need to drill holes the same size of the rivet... and gun it in?

Correct, (and I hope 1501 will also back this up ) when you rivet, you need to drill the hole out the same size as the rivet. Not too small or too large, if it's too small you will not be able to get the rivet in. If the hole is too large, the rivet will not be 100% efficient as the rivet could wobble in the hole. Now, with adding the rivets in a zig-zag pattern, that might be a little over kill. But it never hurts to add security for such an important component.

[s_forbes]

Since the wheels are molded, I wonder how difficult it would be to have ridges formed on the inside of the lip? (or if it would even solve the problem... adding rivets seems like an easy enough solution) Also out of curiosity, what size wheels did people who didn't rivet experience slip with?

359 had a different kind of failure with one of their 8" plaction wheels, as pictured below.

[MarkoRamius1086]

Holy Torque! What on earth did you do to that wheel?

And thank you a bunch Mr. Cormier!

[Tom Line]

As a warning to ALL the teams using plaction wheels: absolutely DO not trust sprockets on those wheels to anything less than 6 through-bolts. Do NOT thread those fasteners into the plastic - use the locknuts. Finally, and perhaps most important, do NOT use the fasteners you get from Home Depot to hold those sprockets on. Those are low grade (usually 2) garbage and will stretch under the strain.

We learned about the bolts this year. Last year we used 3 home depot grade in each wheel with no issue. This year, we were short on fasteners on the practice bot so we tried 3 per and quickly sheared them. We moved up the 6 per wheel, but those kept loosening up. On our comp bot, the 6 bolts were JUST starting to break at the end of West Michigan - we had to call a time out to replace some and tension all the rest. (We have 8 wheel drive traction and have spent some time pushing ).

It's worth the money to pick up some grade 8's and do it right the first time.

[waialua359]

Originally Posted by s_forbes

Since the wheels are molded, I wonder how difficult it would be to have ridges formed on the inside of the lip? (or if it would even solve the problem... adding rivets seems like an easy enough solution) Also out of curiosity, what size wheels did people who didn't rivet experience slip with?

359 had a different kind of failure with one of their 8" plaction wheels, as pictured below.

In SD, we never broke a single one.
In AZ, as shown in pic above, we broke 5 plaction wheels similar to the one shown.
We just ordered 8 more for our next 2 tournaments.