pic: Concept 8wd Drivetrain

[sdcantrell56]

An 8 wheeled robot is actually much easier to make and design. All you have to do is run an extra axle and chain versus a 6 wheel design. For treads you really need at least 4 wheels/idlers per side so there is no reduction in complexity. The only thing easier about treads is the lack of chains. Although if you do a quick search you will see many many negatives about tank treads, namely there propensity to snap under side-loads and there high cost. Each tread will cost around $270 dollars.

The drive cogs for treads are heavy as well and the tread itself is heavy particularly compared to 8 plastic wheels and #25 chain. Unless there is a game that involves sand or other loose material, I as well as most people in FIRST will be hard pressed to consider treads as a viable option given the cost, weight, and reliability aspect.

Also how is it any harder to align 8 wheels versus 6 or versus 8-10wheels/idlers in the case of treads. If there is a problem with alignment then it will render any drivetrain useless, not just an 8 wheel drive robot