Tank Treads

I was wondering where you can purchase treads for a tank drive. What sizes do they typically come in? How much do they normally run?

I was thinking about using the drive belts for harley davidson motorcycles for treads. I can cannot find any for one thing, and they probably are expensive

i looked on google real quick for “conveyor belt suppliers” and found this…


try looking in “package handling” or “light industrial”, some of those materials look like they would stand up to our competetions.

just look around on google or something. I’ll find out where we get ours from and post it later also.

www.brecoflex.com

amazing belts, we have run all the weeks of testing, a regional, an soon to be like 4 offseasons on our first set. They have some amazing traction, we were never pushed at BAE. they are also self tracking to prevent throwing belts.
http://www.chiefdelphi.com/forums/pictures.php?s=&action=single&picid=6139&direction=DESC&sort=date&perrow=4&trows=3&quiet=Verbose

which item are those in the catalog?

The biggest thing to keep in mind with tracks is the strength of the track. You don’t wanna be blowin your belts. I suggest the brecoflex tracks also. Our team had quite a large amount of success with them this season. They are easy to work with and have awesome traction…almost too much traction. You just gotta be careful how much you put on the ground. In the past weve also used timing belts. They are okay but I’d take the brecoflex tracks of them anyday.

-Pat

What series and size of belts did you use from brecoflex? also did you have any problems turning on the carpet with the treads?
-Aaron

we did have a problem turning…however the reason was we had so much of a footprint on the carpet. we easily fixed that by increasing the center idler pulley of our drive. we are now able to turn on a dime and have an amazing amount of torque.

as for the series, ask Pat (team134guy) he should know. i dont know off the top of my head

According to my handy dandy Brecoflex binder, Linatex, Super grip, Correx gum, PVC Blue, Polyurethane, and a few others have the highest CoF’s.

I could go through the whole catalog and tell you what your options are, but that’d take way too much time :smiley:

Go to www.brecoflex.com and order one of their free product catalogs. They’ll send you a binder with whatever inserts you choose. They sent me mine in two days, if I remember correctly, and they come with a wealth of information.

We used Brecoflex as well. We used used two “bogy” wheels on each track toward the center of the bot that were about 1/8 of an inch lower that the others. This greatly improves turning. We also used spring loaded tensioners to keep the tracks tight rather than having one sliding wheel that you lock in place. We’ve used this system for two years now and never had a belt come off or break.

these threads should help when choosing treads vs wheels

http://www.chiefdelphi.com/forums/showthread.php?t=23881&highlight=tank+treads

http://www.chiefdelphi.com/forums/showthread.php?t=23601&highlight=tank+treads

also if you are searching google for distributers…try searching for timing belts

I couldn’t find a series number. I believe its a custom belt so this is what we have. We used a PVC base backed 75mm wide w/ I believe a polyurethane timing belt. We got the self aligning tooth assortment w/ two pulleys to match. Def use the pulleys. Theyre designed for this track and will save you some machine…SOME they are heavy so youll have to take some out. I’m not sure on the length…but you can figure out what you need.

You can use this catalog though. The selection is nearly endless, you can mix and match til you find what you like.

BTW we did have trouble turning. My suggestion is put a larger center idler in to help reduce the footprint. We went w/ i believe 4 one hundreths of an inch.

To keep tension we used a piece of threaded rod with the axle. The base was slotted so it could slide. Then just double nutted it. Illustrated below. n=nut O=axle

n

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n

-Pat

1024 used treads from brecoflex for the past two year.

the picture is of this years tread:
http://www.chiefdelphi.com/forums/showthread.php?t=25346

as for turning on carpet the center metal pulley is lower creating a bow in the tread allowing us to turn on a dime.

Team 1097 has used treads since the forming of our team. Our origional treads were from a snowblower donated to us from Tahoe Sports and Motor. This year we used this website listed somewhere in the chiefdelphi discussion above: http://www.robotcombat.com/store_tanktreads.html They were basically modified forms of snowblower treads that you could buy seperately from the snowblower. We then machined some of the parts down for use on our bot. We ran out of time to machine the cogs, which would have been nice, since they were expensive. Just to give you an alternate option to Breco, which can be expensive. I think this entire year we were pushed once, maybe twice, and the treads have always been a major benefit for defensive strategies.

What exactly do you mean when you say you reaised the center pulley to decrease the footprint. IF you would like i can include a CAD drawing of what i have in mind as far as how we want to lay things out.

yes if you looked at the side of the bot, the middle idler pulley was set about a half an inch below the other two pulley, ccutting the footprint in half but making it turn

In the 2003 season we used similar treads, the craftsman snowblower treads they were good, cheaper than brecoflex but didnt quite have the traction the brecoflex did. Def. good for a newer team to use to make a good sturdy/powerful drivetrain and def. a gateway to designing track systems.

Side note: We didnt lower the idler(middle wheel). What we did was just use a larger wheel so it offset each of the two drive cogs sorta like this

O O O

Okay its upside down but you get the point.

234 used treads on our 2004 robot that were specifically made for climbing stairs and for great traction. The most unique feature is the 24mm pitch…they are some of the most aggressive treads around! We were very pleased and they were easy to work with. For pictures and ordering info: http://www.thistle.uk.com/stairclimbing.html

1141 used a pair of old snowblower treads for our first year. They didn’t give us a huge amount of traction, mainly because our drill motors were unscrewing themselves from our drivetrain, and if we tried to push, we’d put ourselves out for the match. If you’re looking for the cheap direction to go, they cost us a trip to the dump.

Nobody has mentioned cost yet, surprisingly. Just a belt can set you back around $200, if I remember correctly, and the pulleys for the belts will cost you a pretty penny as well. Most teams who use treads end up needed more than one belt obviously, since they tear, wear down, etc.

All this adds up to quite a bit, and can be very prohibitive for some teams.

Cory

Yes the brecoflex will cost you. But these belts are built specifically for this application. They are built to last. We are still on our first set of belts. We’ve gone through practice and testing, demos a competition and within the next month and a half two more. We are comfortably within the belts working limits. They are very durable belts (least the set we are using).
You really gotta look at your application and and cost benefit relation.

-Pat