Brecoflex Treads

[ProgramLuke]

Originally Posted by topgun

Clicking on the images you sent shows that only the Linatex Red and PVC White are 1.1 CoF. The rest are lower than that. I thought that Blue Nitrile from McMaster was either 1.1 or 1.2, but I don't have that right now. Maybe someone else can chime in on that.

Rather than grinding off the teeth, perhaps you could use the stock pulleys or bar stock to make your own wheels to the exact size you want. Then rivet the belting to your homemade wheel. Or you could just cut to size and rivet to the AM wheels.

The figure in the document provided for robotics teams shows the CoF's on different surfaces. On the product page the surface is not listed so that isn't really an accurate meter. The CoF's listed in the OP are listed as being measured on carpet.

Originally Posted by http://www.brecoflex.com/index.php?CATID=7&SCATID=64

Name---------------Carpet------Diamond Plate---Polycarbonate Clear
Supergrip Green-1.5-----------0.7-------------------0.7
Supergrip Blue---1.5-----------0.6-------------------0.7
Red Linatex-------1.6-----------0.9-------------------1.4

[Jared Russell]

When it comes to CoF, measuring it yourself is really the only way to do it. Do not trust numbers you see online from manufacturers - we have seen actual CoF vary by 50% or more on multiple occasions.

The interaction of a wheel with a carpeted surface is complex, and Coulomb friction is but one of the factors. Play around a bit with a few of the common FRC tread materials in a number of configurations (play with the diameter and width of the wheels), and you will find that a 1.3 CoF for something like Roughtop is, at best, a nominal value.

[ProgramLuke]

Has anyone used these that would be willing to share results of some of their testing? I am most specifically interested in the Supergrip Blue, as searches on CD have shown that it wears much slower then the normal brown roughtop.

[jhellr13]

Originally Posted by ProgramLuke

Has anyone used these that would be willing to share results of some of their testing? I am most specifically interested in the Supergrip Blue, as searches on CD have shown that it wears much slower then the normal brown roughtop.

My team used the treads in 2010. I remember they had great traction and were pretty durable. Turning the robot was something you always had to be concerned about. I never drove that robot, but i remember hearing that you couldn't just jolt into a turn. You had to slowly guide the joystick. It also had great pushing power. We tipped over a robot one time. The treads did have their flaws though. At our regional, after the first practice round, one tread snapped. The extras we had ordered were still being produced at the factory, because we figured we would just order another pair for off season events and future use. Luckily, someone was able to get a hold of another tread company on the west coast to ship it to us in new york overnight for us to use for the weekend. Also, i remember at an off season event, the treads had a tension problem that kept stopping us in the matches. Overall, they worked pretty nicely though. Hopes this helps

[ProgramLuke]

Originally Posted by jhellr13

My team used the treads in 2010. I remember they had great traction and were pretty durable. Turning the robot was something you always had to be concerned about. I never drove that robot, but i remember hearing that you couldn't just jolt into a turn. You had to slowly guide the joystick. It also had great pushing power. We tipped over a robot one time. The treads did have their flaws though. At our regional, after the first practice round, one tread snapped.

Can you tell me more about your 2010 drivetrain you referenced? Was it a 6wd drop center or a tank tread setup that snapped the belt and provided issues with turning?

[jhellr13]

Originally Posted by ProgramLuke

Can you tell me more about your 2010 drivetrain you referenced? Was it a 6wd drop center or a tank tread setup that snapped the belt and provided issues with turning?

it was a tank tread setup though i think they drove it in arcade with the option to use tank. not too sure

[ProgramLuke]

Originally Posted by jhellr13

it was a tank tread setup though i think they drove it in arcade with the option to use tank. not too sure

I think you may be confusing tank drive (two joysticks) with a tank tread drive system (http://www.chiefdelphi.com/media/photos/29463) .

The treads we would order would be used in a 6wd setup such as http://www.chiefdelphi.com/media/photos/36924.

[Mark McLeod]

1751 used tank treads in 2010.
The steering control setup was something else.

[Gary Dillard]

Originally Posted by ProgramLuke

Has anyone used these that would be willing to share results of some of their testing? I am most specifically interested in the Supergrip Blue, as searches on CD have shown that it wears much slower then the normal brown roughtop.

There is a paper in CD media where my daughter tested the green belts about 8 years ago.

The Paper

The Data

[Chris is me]

So more pressure leads to a greater interlock effect and more traction? So for that particular material, less contact patch pushes better. Heh.

I imagine that making a track wider and making a track longer have different effects, since wider increases the number of "spikes" and longer just spreads the load out more.

[Chris Hibner]

It's been a long time (2004, I believe) since a team I was on used treads, so take this for what you will.

As noted, back in the day Brecoflex treads did have a bit of a strength issue, so we didn't use them. We used treads from Mectrol that had the same backing as the Brecoflex treads, but they were Kevlar reinforced and had a failure strength in the area of 1500 lb. We never had one fail (and if you saw our 2002 robot in Ken Patton's / Paul Copioli's drivetrain presentation, you would realize how impressive that is).

I don't even know if Mectrol is still in business, but I'm sure you can find some treads with the Kevlar reinforcement that will help keep them from breaking.