pic: Track System

[pakratt1991]

actually it wasn't that bad, we can move while being pushed from the side with a normal team, but this was against a beefy drive train and the brecoflex belts have a steel whire running in them and rather then jump they snap... while some teams when being pushed from the side move sideways, we do not move at all. just something we have to deal with, next year this wont happen, we are improving the rollers

[Otaku]

670 was being pushed around left and right though, at SVR, Davis, and ATL.

I've thought about tank tread -- and while it is cool looking and works well, our team went with 4-wheel tank-style drive and haven't lost a pushing match once (well, maybe once to 1662...)

[M4 Sherman]

All hail the tank track! The tank track is the coolest drive train set up out there. (just look at the M4 Sherman)

But, its not cost effective, and they can be a bit slow and hard to turn. Just look at some of the new Military APCs that use a wheel system rather than tracks.

For these tracks, they turn just as good as a 6 wheel, and for a full drive system, only cost $1200.

[Cory]

Originally Posted by 114ManualLabor

For these tracks, they turn just as good as a 6 wheel, and for a full drive system, only cost $1200.

I'd debate the first half of your statement, but the second half is a little more interesting.

$1200? Maybe you just didn't elaborate, but that's illegal. There's a maximum price per component of $400. In addition there is now a rule that says entire subassemblies cannot be purchased from a vendor.

Given that the above is true, even if you split the system into two sides, you're looking at $600 per component, and you still have a complete subassembly, which clearly doesn't work with the 2007 rules.

I was under the impression teams using the tracks were all sponsored by Outback Manufacturing, not paying for the tracks. Could someone clear that up?

[Gabe]

The tracks cost $300 a piece (2x=$600), and the material is cost covered by the team ($600), while Sam does the machining for them. Since you are not purchasing a finished assembly, rather the costs associated with the manufacturing, they do not fall under the same rule.

[sdcantrell56]

$1200 seems a bit ridiculous for a drivetrain. Does that include transmissions, because I guess that would make it a little more comparable to a wheeled drivetrain.

[Cory]

Originally Posted by Gabe

The tracks cost $300 a piece (2x=$600), and the material is cost covered by the team ($600), while Sam does the machining for them. Since you are not purchasing a finished assembly, rather the costs associated with the manufacturing, they do not fall under the same rule.

You are purchasing a finished assembly--an entire drive system.

We're talking about two different rules. You're talking about manufacturing costs. I'm talking about the fact that you cannot buy a completed subassembly under the 2007 robot rules, which is exactly what these tracks are.

[Alpha 997]

Originally Posted by Cory

You are purchasing a finished assembly--an entire drive system.

We're talking about two different rules. You're talking about manufacturing costs. I'm talking about the fact that you cannot buy a completed subassembly under the 2007 robot rules, which is exactly what these tracks are.

Actually these tracks are completely legal, we made sure of that. I don’t know about any other team, but for us, we did not purchase the track from outback. $1200 is the estimate for the cost of the material that made up the tracks, not how much we paid outback for the tracks. Outback, as our sponsor, then machined the track parts out of the material that we provided. They gave us the pieces that they machined, and then we assembled it together. We did not purchase anything from Outback. The AndyMark transmission were bought separately.

[pakratt1991]

You are purchasing a finished assembly--an entire drive system.

We're talking about two different rules. You're talking about manufacturing costs. I'm talking about the fact that you cannot buy a completed subassembly under the 2007 robot rules, which is exactly what these tracks are.

we ordered the belts seperatly so nothing cost more then the cost limit and theirfore they were legal, also the 600 dollars that we paid outback was for materials and he sponsored us the cost of machining.

Originally Posted by kramarczyk

Is this statement based upon something, like math, or just a subjective observation?

Both. The center pulley is lowered about a tenth of an inch. I also watched these, got a chance to play with them, have the CAD, and have done massive research on them.

[Alpha 997]

Originally Posted by 114ManualLabor

Both. The center pulley is lowered about a tenth of an inch. I also watched these, got a chance to play with them, have the CAD, and have done massive research on them.

I think that the center roller should be set lower. The little difference it had pretty much didn't matter on carpet when 100 lbs of robot is pushing down on it.

Originally Posted by Cory

You are purchasing a finished assembly--an entire drive system.

We're talking about two different rules. You're talking about manufacturing costs. I'm talking about the fact that you cannot buy a completed subassembly under the 2007 robot rules, which is exactly what these tracks are.

A couple things... The cost issue is beaten back by the fact that the bill is for individual pieces or the system. Machine time is donated to Outback teams that choose to work with them. Also, it gives teams who don't posses the huge resources of larger, more powerful teams, a better chance at having a highly competitive drive system.

[Travis Covington]

So you guys think that if AndyMark sold their transmissions unassembled and billed you for the parts individually that they could be selling them for more than $400? Not quite.

No matter how you try to justify it, $600 worth of parts that are meant to be assembled together is the same as a $600 part... I don't see where the argument is.

[kramarczyk]

Originally Posted by 114ManualLabor

Both. The center pulley is lowered about a tenth of an inch. I also watched these, got a chance to play with them, have the CAD, and have done massive research on them.

OK, so enlighten me, what metric(s) did you compare and how did you calculate it (them).
Where did you get the research data and what intermediate conclusions did it allow you to draw.

i.e. Treads are good because they distribute the load and allow the weight concentration to be more central compared to a 4x4 system which decreases the energy lost to scrubbing the wheels without reducing forward tractive force. - Drivetrain Basics White Paper - Chris Hibner - http://www.chiefdelphi.com/media/papers/1443

Note: I am not trying to hijack this thread with a discussion of what is the "proper" amount center wheel drop, so lets leave that discussion for another thread.