4 DOF mobile robotic arm

Have you ever tried to build a big robot, so big that you'd need multiple brains and definitely multiple power sources?  Well, up to now I have wanted to, but I did not have all the pieces, motors, and ways to control them.
  For maybe a year I have gotten close to big because of the amount of Legos I had obtained, but I still wasn't quite there.  This year for my birthday I received an Arduino and decided to use it for a second motor controller.  Since the Arduino can provide five volts only, I used it to manipulate the servos controlling the pneumatic switches.

 

  Now, this may seem great, but after putting it all together, the parts I still needed coming in the mail, I ran the quick test program I always do (to work out the last details,) and realized something important. Even though I had geared the motors down, they were not moving... the robot was just too heavy.  I decided to remodel using worm gears this time to see if I could get any movement at all.  Now that that is done, it is all moving smoothly, though extremely slowly. 
  After witnessing the extreme slowness produced by the heavy-ness of my machine, I decided to do a bit of  research on NXTLog to see if anybody had gotten a large and complex robot to go very fast at all.  It seems that nobody has... at least, I did not see any body getting a robot with as many motors and all in all weight as my bot to traverse with any speed to talk about.  Well that is interesting, I wonder if there are any other, more powerful motors for cheap that could be adapted for use in a Lego robot.

for more pictures of my Mobile Robotic Arm, click HERE.