So here's the deal folks, I scored this cool "Vex" starter kit... FREE!!
It is not actually a robot as it sits, more a build-your-own R/C car (you have to buy additional doo-dads to program it). However, EVERYTHING is hackable. Everything is a standard servo, either a 360 degree "motor" servo or a standard one. There are plenty of gears, collars, axles, wheels and the like.
This is simply the most solid, changable robot test bed one could ask for...
For example, I wanted to try a three wheel robot with the third wheel being steered by a servo, well...
Now here's what's cool, the transmitter is very, very programable. --I simply programmed it to "mix" the main steering channel and the back wheel servo. Right now I have it set to turn the servo 50% of how far the stick is moved. I can adjust how much is mixed on the transmitter. --Back to the cool part-- I should be a peice of cake to program a 28x to "mix" two channels and sence I have done an "erector-set" prototype I know the mechanics will work.
Another thing I like is the main drive is with servo motors. They only need one output each to work thus freeing up 2 channels and no need for a L293D. Very Cool. --I'll get you all some video soon.