Minibot wheels

how many wheels can be on a mini bot?

infinite…assuming they are a tetrix wheel of course

Half right. No where does it say they have to be Tetrix wheels.

You can use as many wheels as you want, but if you don’t use tetrix wheels you have to make them out of the allowable materials…(listed below)

A. TETRIX components that are not in violation of any other rules,
B. no more than two motors (PN W739083/W739023) and an unlimited number of Tetrix servos),
C. no more than one 12V rechargeable NiMH battery pack identical to those supplied in the FTC kit of parts (PN W739057),
D. No more than one HiTechnic DC motor controllers,
E. No more than one NXT controller with the Bluetooth functionality disabled,
F. Polycarbonate,
G. Polycarbonate glue,
H. Raw aluminum sheet, 90° angle, u-channel, tube, bar, that is not sold in pre-perforated or pre-punched form.
I. rivets,
J. non-metallic rope or cord,
K. wire nuts,
L. cable ties,
M. limit switches,
N. no more than two common household light switches,
O. electrical hookup wire,
P. non-slip pad,
Q. PVC or CPVC pipe,
R. PVC cement or cleaner,
S. Mechanical fasteners (e.g. screws, bolts, etc),
T. Loctite or similar thread-locking product,
U. Rubber bands,
V. Surgical tubing,
W. Electrical tape and shrink tubing,
X. PWM extension cables,
Y. Universal security clips to hold the PWM connectors together,
Z. Hook and loop fastener (may not be used as tape),
AA. Magnets, and
BB. NXT compatible sensors and related connectors/cables.

as many as you can fit in a 12x12x12 box

Technically not infinite because eventually you will be above 15lbs.

You just have to make them infinitely light.

No where in the rules does it say you can use other wheels besides Tetrix wheels.

Unless you make them yourself out of the materials allotted.

<R92> has very restricitive language for aluminum in part “H”, but gives no such restricitions for polycarb in part “F”. AndyMark plaction wheels are entirely polycarb and the bolts holding it together would be legal fastners. I don’t believe their hubs or treads would be legal though.

http://www.andymark.com/SearchResults.asp?Cat=103

I don’t see why you’d want to use AndyMark wheels (which are bigger and heavier than Tetrix wheels) when you could just machine your own or buy small ones that happen to be made of polycarbonate.

I could think of some advantages to using a 6 or 8 inch wheel with flanges to help guide the robot on the pole. The point however was not to intimate that AndyMark wheels are the solution. The point was that the rules do not restrict you to raw materials only for polycarb. Preformed materials are allowed. Q&A even clarified this point here. http://forums.usfirst.org/showthread.php?t=16317