AndyMark Plaction Wheels

[blayde5]

http://www.andymark.biz/am-0514.html

My team has started using these wheels this year and for the most part we get good performance out of them.

However we've noticed that AndyMark joins the treads with staples. During both of our competitions we've found the treads to start coming off and during one of our matches at SVR, the tread actually did come off.

To solve it we just riveted the ends of the tread and it seems to work okay.

Any other teams using these wheels have the same issue?

[Tom Line]

Pretty much all the teams I've talked to have the same issue.

They use one of two solutions:

1. More, bigger staples to keep the ends together
2. Rivet the tread to the wheel.

[Chris is me]

This happened to us too. I kinda expected it to happen. Riveting on the tread was one of those things we kept putting on the list of things to do, but never did.

Two rivets per wheel did the trick. Everyone should do this always.

[Edoc'sil]

if it comes off at a competition a drill and a zip tie does the trick as well too.

[Jamie Kalb]

This happened to us, too. Same issue, same solution.

[Chris is me]

Originally Posted by Edoc'sil

if it comes off at a competition a drill and a zip tie does the trick as well too.

If you're already drilling the hole, why not rivet it? If you need a hand pop rivet gun, you can borrow my team's gun.

[eugenebrooks]

We had the treads come off during light testing just prior to ship.
We riveted, but the treads came loose again.

We solved the problem with a method identical to how
we used to make good wheels from KOP wheels. We cut
the flanges off and then sanded the rims using a belt sander
right on the robot. We usually use a lathe for this, but we
did not want to take 8 wheels off the robot at this point.
We made our own treads using incline belting from McMaster,
by carefully sanding the first layer of nylon off the backing,
just exposing the black rubber layer. We then cut the treads
and glued them on the wheels with mid-cure crazy glue, using
no rivets or screws, after cleaning the tread and the rim with
MEK (or acetone if you don't have MEK handy).

No tread came loose at SVR. When we rip a tread off of one
of these wheels, it leaves the black rubber from the tread on
the wheel rim all the way around. Screws or rivets are not
needed at all when using this gluing procedure. In the rare
event that a tread does start to peel we use some glue on
it and it rarely starts to peel again.

Eugene

[mahumnut]

our team trimmed the tread itself because it was overlapping the raised edges of the wheel, we then used rivets. After the DC regional, we ordered their aluminum version because the plastic ones kept on breaking when our robot went over the hump. Because our robot was 6 wheeled, the hump wasn't the smoothest trip crossing the zones.

[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*

[jfc358]

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.

[Madison]

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.

[M. Mellott]

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.