Plactions treads and rubbing alchohol

[lemiant]

I'm looking for some ways to add a little bit more traction to our robot on the bridge. We are currently using plaction wheels with rough top tread. I have ordered some wedge-top tread for use at worlds, because I think it might be stickier. Does anyone have experience comparing the two treads on polycarb. Also, in the past we have used rubbing alchohol on the treads to increase traction. Will that degrade the tread?

Thanks

- Alex

[Andrew Lawrence]

Overall, roughtop treads have better traction on carpet than wedgetop, but teams have found that wedgetop has better traction than roughtop on surfaces such as polycarb.

Please note that while I haven't thoroughly tested this, roughtop worked beautifully for us on the bridge at both regionals we went to, and we balanced the same, sometimes better, than the wedgetop tread users, so I think the difference is negligible.

Also note that wedgetop tread needs to be replaced much more often than roughtop tread.

I have no idea about the rubbing alcohol thing, but honestly the two treads are grippy enough. If you really want more grip, try blue nitrile tread. It can be found at McMaster. One of the grippiest things out there, and can go through seasons without loosing its effect.

[IndySam]

What size wheels are you using? If they are 6" just use the KOP wheels, they are great on the bridge and are a nice cheep solution.

[jyh947]

What size wheels are you using? If they are 6" just use the KOP wheels, they are great on the bridge and are a nice cheep solution.

Although our competition robot uses wedgetop treads, I second the 2012 KOP wheels. They have very high traction.

[lemiant]

What size wheels are you using? If they are 6" just use the KOP wheels, they are great on the bridge and are a nice cheep solution.

4" Plaction Wheels.

[Ether]

HDPE (what's on the bridge)

Last I checked it was polycarbonate.

Have they changed it?

HDPE is much more slippery than polycarb.

[Andrew Lawrence]

Last I checked it was polycarbonate.

Have they changed it?

HDPE is much more slippery than polycarb.




I may be wrong, but I remember hearing about HDPE being on the bridge.

[Andrew Schreiber]

I may be wrong, but I remember hearing about HDPE being on the bridge.

I remember hearing that too but it is polycarb on the competition bridges.

[Gregor]

If you really want more grip, try blue nitrile tread. It can be found at McMaster. One of the grippiest things out there, and can go through seasons without loosing its effect.

Can you link this? My abysmal searching skills have come up empty.:ahh:

[MichaelBick]

Can you link this? My abysmal searching skills have come up empty.:ahh:

http://www.mcmaster.com/#rough-top-belts/=h7j13c

It's the abrasion resistant nitrile.

[Joe Ross]

The colored part, the "bridge deck" is HDPE. On top of that is clear polycarbonate, the "bridge surface".

[Hawiian Cadder]

If you want to add grip I would try to remove the effect of the molding draft from the plasticons. Bowing the tread out so that the MIDDLE of the wheel rather than the outer edges has the largest diameter will greatly increase grip.

[Peter Matteson]

Do some research on the materials. There is a very specific reason the the Buna-N-Rubber, Nitrile and Natural rubber most teams use does not work as well on the bridge polycarb.

[Anupam Goli]

For the teams that have used the Blue Nitrile tread, how do you cut the tread down to a width that's manageable? I see 3" ad the minimum width, and I'm pretty sure 3" will be too much for manageable turning.

[Andrew Lawrence]

For the teams that have used the Blue Nitrile tread, how do you cut the tread down to a width that's manageable? I see 3" ad the minimum width, and I'm pretty sure 3" will be too much for manageable turning.

Scissors, a knife, sometimes a saw blade....just about anything cuts it. Just find the width you want, measure (twice), mark the area, and cut.

[jwfoss]

For the teams that have used the Blue Nitrile tread, how do you cut the tread down to a width that's manageable? I see 3" ad the minimum width, and I'm pretty sure 3" will be too much for manageable turning.

When I was on teams who used this material we always marked the back side of it and cut it tread side down on a bandsaw.

[thefro526]

When I was on teams who used this material we always marked the back side of it and cut it tread side down on a bandsaw.

The few times that I've cut Blue Nitrile, I've used a bandsaw as well. I've found that the only way to get a remotely straight cut was to clam a piece of angle (or other material) to the table of the saw to act as a guide.

[Anupam Goli]

I was hoping to avoid using a bandsaw... My shaky fingers often mess up cuts, and those burs really are annoying. How much more advantage does Blue Nitrile have over roughtop or Colson?

[Jared Russell]

We often use a box cutter or razor blade (along with a clamped-down straight edge) to cut our tread to length and width. It isn't too difficult.

Based on qualitative observations (and a few quantitative experiments), blue nitrile outgrips Colson wheels on carpet (particular with wide, small diameter wheels), but on HDPE and polycarbonate surfaces, the Colsons grip a bit better. Adding custom tread patterns to the Colsons supposedly closes the gap with roughtop tread on carpet.

[Andrew Lawrence]

I was hoping to avoid using a bandsaw... My shaky fingers often mess up cuts, and those burs really are annoying. How much more advantage does Blue Nitrile have over roughtop or Colson?

I hear it's pretty grippy, and wears really well....but that's it. If you get into a pushing match with roughtops vs. nitrile, both with similar gearboxes/speeds, you're not going to find one will be drastically better than the other.

If you don't think it's worth the hassle, just use roughtop/colsons. You're not going to loose any needed power.

[sdcantrell56]

I hear it's pretty grippy, and wears really well....but that's it. If you get into a pushing match with roughtops vs. nitrile, both with similar gearboxes/speeds, you're not going to find one will be drastically better than the other.

If you don't think it's worth the hassle, just use roughtop/colsons. You're not going to loose any needed power.

Just to clarify. Nitrile is a material while roughtop is a tread pattern. You can get nitrile roughtop or neoprene roughtop or a couple other rubbers. Nitrile is just about the least grippy of all the potential materials but not by much and its wear characteristics are much better than some of the other materials. That said...I still prefer colsons.

[Anupam Goli]

....That said...I still prefer colsons.

Of course, the only thing preventing me from using colsons is the time and financial cost of making your own live axle hubs for them.

[jwfoss]

Of course, the only thing preventing me from using colsons is the time and financial cost of making your own live axle hubs for them.

The financial cost of making your own live axle hubs for colson wheels is actually relatively low. I'd argue less than the cost of buying other types of wheels. See FRC228.

You want a simple live axle plug for the colsons 1.5" wide, buy a piece of 1.25" OD diameter aluminum rod, turn down to 1.2" inches OD, drill thru and broach for whatever you want to drive, and cut to 1 5/8" long. Press in, and drive.

Or just wait a few months, I hear that WCP will be selling live axle plugs in the future.