[GlennGraham]

I'm a long time LEGO robotics coach and have been investigating the Vex product to see what will be instore for my team when they graduate from FLL.

I've explored several types of "mobility" beyond the simple 4wheel starter example.

The tank treads are a great buy if you need to travel over uneven/loose terrain.

The starter kit only has two of each of the larger wheels - buy more wheels if you need 4/6 large wheels for ground clearence, etc.

I've been tweeking a 6wheel design and I've found that the larger wheels have great traction, to the point of having problems turning on a smooth wood floor. I've gone to a two large wheels, one centered on each side with 4 omni wheels, 2 front/back on each side. This has great turning on the smooth floor, great lateral traction, and (since all 6 wheels are driven) can climb up ramps well.

I've also been investigating the implementation of an articulated arm.

I needed to gear down the motors to get enough torque so I quickly ran out of gears - buy more.

I wanted to place the motors as far "inward" as possible along the arm to reduce the effect of their weight. I've been using chain and sprockets and its worked well - buy some.

The FLL robots rely on autonomous behavior. I don't want to lose that aspect when we move to Vex. I ended up buying rotation, ultra sonic, and light sensors so the robot can sense its surroundings - not needed if you just R/C the bot around.

No extra switches purchased. Haven't used up the ones provided in the starter kit.

Hope that helps,
-Glenn Graham