It also uses a small amount of pieces, and one of the more common motors.
Step 1: Parts List
16 blue spacers
22 silver spacers
1 Knex Powerpack (Short or long stringed, doesn't matter).
Step 2: Sides
1: Make this. Remember the green rods
2: Make this part as well. Make sure to get the spacers right
3: Close up...
4: Put the two together to get this
5: Make its twin. It is an exact mirror image
6: Put two red rods on one of the sides like this.
Step 3: Core
1: Make this panel
2: Make another panel and put the rods on like so
3: That piece from another angle. Those are tan clips on blue rods
4: Slip the motor onto the panel like so
5: Put the other panel on and put two more tan caps on the blue rods at the top
6: Get these pieces ready
7: Put it through the white connector like so, and put the other spacer and red connector on the other side. Make sure that they are connected facing the same direction
8: It should look like this from above
9: Make make this attachment on the end. Pretty simple
10: Make another one on the other end
11: It should now look like this. Notice that all the reds are facing the same direction
Step 4: Assembley
1: Take the side with the reds and position it with the core like so
2: Connect all the blue rods to the red connectors on the core
3: Close up
4: Put the other side on the same way
5: Connect The red rod going across like so
Whoop whoop, you are done!
Step 5: Usage
I hope you liked this instructable. Comments and questions welcome.