Robot 1: "Little Jimmy" based on PICAXE-18M2

I wanted to build this little robot to give me a fun and flexible platform for learning more about programming, RC (radio-control), drive trains (the mechanics that make it go) and the newest PICAXE processor, the 18M2. Under a modest budget, I sought to salvage materials and build as much as I could rather than purchase a kit. Since I live in an apartment, my available tools were also limited to some basic hand tools: drill, hacksaw, files, etc. This will be a remote-controlled tele-presence once I purchase a wireless video camera from E-Bay and mount it on the pan and tilt servo: otherwise, the robot is complete. 'Little Jimmy' has entertained my wife and neighbors with his nimble agility. Most of all, this project taught me a lot and earned a sense of genuine pride and accomplishment. Though the robot is RC controlled, it can just as easily become fully autonomous by reprogramming its PIC 'brain'.

Some basic specs:

1 Size 10x10x9.5 inches
2 Weight 9.5 lbs (half the weight is in the battery, you could use a smaller one)
3 Weight Class Hobby Weight <=12lbs
4 Speed 0.45 MPH
5 Speed 0.67 FPS
6 Wheel Rotation 53 RPM
7 Battery Dimensions 4x3.5x2.75 inches
8 Battery Weight 4.5 lbs
9 Battery Gel Cell 12 V, 5Ah
10 RC System 2.4 Ghz
11 Current Draw F or R 0.5 A
12 Current Draw rotate 1.2 A
13 Estimated run time 6 h

Step 1 Attach Motors to Wheels

I lucked out in obtaining 4 surplus gear-head motors that rotate at about 53RPM at 12V, 120mA each at no cost; you would expect to pay $15-$25 a piece for equivalent units. These have a 1/4" D-shaft.

Attaching wheels to motors is not as trivial as you might think. The key piece of hardware is called a wheel hub adapter, and I found a good selection at ServoCity [Link] . They also manufactured ABS wheels and motor mounts I used. (Parts list is at the end of this article).
The wheel hub adapter attaches to the motor shaft via a set screw, and the wheel is secured to the hub with 4 socket-head cap screws.