Tank treads for "white" 2013 KOP wheels

FIRST General Forum
1

Our team, in the off season wants to make a robot using the KOP 6 wheel drive system but wants to put tank tracks on the wheels. We are a second year team and have never done tank tracks before. Would anyone out there know of where we could get some tank tracks that would work for those KOP wheels and/or how we could make them. What have other teams used for tank treads? Any ideas or suggestions you may have would be greatly appreciated. Thanks for a great season everyone and thanks for all the support on this site.

jalmos
Team #4166

2

You can get wheels with treads from vexpro below. You can either buy the wheels and the treads and rivet them together or jet get the tread and rivet it to the white wheels.

http://www.vexrobotics.com/vexpro/wheels-and-hubs/traction-wheels/traction-wheels.html

3

Just make sure that if you rivet just the tread that you tension it right otherwise you are liable to throw a tread quite often

4

I don’t think that’s quite what he means by tank treads. Those could be wheel treads for a tank drive, but he’s after tank treads in their more common form.

I’ve heard of them done using double sided timing belts, but have never done them myself.

A quick search would likely reveal a solid list of teams who have done it. 195 did it in 2006:
http://www.chiefdelphi.com/forums/showthread.php?t=43751&highlight=195+tracks

Edit: Here’s a discussion of tank treads - http://www.chiefdelphi.com/forums/showthread.php?t=68911&highlight=tank+treads
They’re really tricky to do right. They would be really cool, but unless there is some crazy terrain, I highly doubt there will ever be a tank tread drive train that performs at the level of a good quality 6 wheel skid (that’s the setup that comes in the KoP).

5

Thanks for the quick response and help. I will look into all those ideas. Much appreciated.

Thanks for a great FRC season

jalmos

6

I have heard of some teams having some success with this stuff:

http://www.brecoflex.com/index.php?CATID=1

7

1-2 inch wide double sided timing belts worked for us last year to get over the hump. Make sure your center is dropped, or turning will be atrocious.

8

The mentors on our team back when we ran treads (99, 01-03) apparently had nightmares with a device called the “puck” which was essentially a drop down ball caster to raise one side of the robot to turn since we didn’t have a dropped center.

9

I had seen one team (can’t remember who it was :P) that used normal chains as treads. They had I think three chains parallel to each other, spaced maybe an inch apart, but every three links or so, they replaced the link with an attachment link, and riveted a strip of polycarbonate across them.

10

If anyone wants to use this method, just make sure you don’t forget to include something that goes between the chains and the carpet. In almost every recent game there has been a rule against metal traction devices.

11

Yep, that’s what the polycarbonate pieces were for, they were riveted to the outside of the chains, so they touch the ground instead of the chains.

12

We use and have used tank treads every year since 2006 except for 2009.

Here’s a video of this year’s robot, you can see them in action

In essence, we use what IKE posted, the Brecoflex conveyor belts. We drive the drive cog (supplied by Brecoflex, machined to be lighter by us) with VEX Pro Ball Shifters. This is the only point that is actually driven, the rest of the tread is held on with delrin idlers. They spin freely on their axles and most are affixed. The center one is dropped (1/8 or 3/16, I forget but it’s more than 1/16) and the back one is in a channel so the treads can be tensioned.

I’d be more than happy to answer any more questions you or anyone has about tread based drives and I can provide CAD. In fact, we posted our CAD from last year on FRC-Designs and this year’s drive system is nearly identical.

13

I know 1710 tried this. If I recall they had very little traction using poly carbonate treads.

edit: I didn’t find a picture of 1710, but I found this: http://www.chiefdelphi.com/media/photos/25846

14

We have a tank bot using conveyor belt treads with aluminium drive wheels covered in roughtop.

It’s really bad honestly. The belt slips around the drive wheels if we try to go up even the smallest inclines. The belt also slips off the tracks if it gets pushed. The traction is not much better than a 8 wheel tank drive and is MUCH less nimble.