Let's Make Robots!

party 'bot

  ..Will smoke cigarettes and play caps.  (a game like beer pong or beiruit played with only one cup and bottlecaps)  For smoking Im thinking of using some of the bellows from a toy car launcher that you slam down on.  hopefully it can blow smoke rings.  I have though of several ways to compress the bellows, but they dont see plausable.  the rail gear could be used for the motion, but i would need 2 or 4 of them to keep the assembley from binding up.  or i was thinking, i dont know what this type of gear is called, but the one with the offset circles that can do up and down motion. 

hobby motor control

Hi guys, I am looking into getting a small electronic speed controller from the rc hobby store to run a couple of small dc motors (tamiya dual gearbox), does anybody know if these take the same pwm input as running a servo or does the r/c gear use something else? I thought r/c gear used pwm but when browsing online for motor controllers some say pwm, and some say r/c (in addition to analog or serial or whatever else). Is there a difference?