CARDBOARD ROBOT --- DANCE, DANCE, DANCE!!

Step 2: Get motors

This is the kind of robot that runs on motors.  Little robots can use servo motors, which makes motor control simple. But big servos are expensive.  Stepper motors are a good option, they can be precisely controlled and most are easy to mount.  I'll be hooking some up towards the end of this project.  

Right now I'm going for quick and dirty.

So, HarborFreight.com here I come!

I bought a bunch of cordless drills from Harbor Freight for about 15$ each.  They come with the motor (of course), 18V battery, and charger.  That is a pretty good price for all that.  Also I like the way you can just jam stuff in the drill chuck and tighten it down.  Nothing easier than that for attaching an axle, drive-screw, or whatever.

The problem with these motors, is that with coil resistance of only 0.5ohm and a 18V power supply, we are dealing with alot of power.  (some math:  V = IR... so I = V/R  or I = 18/.5  which is 36Amps)  ( more math: W = VI (right?)  or W = 36 * 18 which is 648 Watts (is that right?)  if that is correct, then running these at full power uses as much power a 6-and-a-half 100 watt light bulbs (really?)) 

If you are used to regular Arduino type stuff, then this kind of power will, as they say, burn up your sh*t.  (even if my math is wrong - 648 watts? yikes)

But let's deal with that latter and play with the boxes!