2002 Pictures
Source of the runners
All three runners were made from two carbon steel butcher knives. The top piece will be cut in two to make a front runner and one of the rear runners.
Here the runners are attached to their angle aluminum brackets. You can also see the plexiglass runner board here.
Grinding the Runners
All three runners needed a very shallow, but exact radius. So that they would have a single contact point. We made this jig to give us the control we needed. You can see one of the rear runners attached to the end of the jig.
Here you can see the front runner, pivot, connecting rod, and runner board with runners attached. All the blade edges were taped to protect them. (The piece of plexiglass that the pivot and servo are attached to was not used.
Gear box
Here you can see our 2:1 gear box. The motor sits in the cradle where the screwdriver is. This gear box allowed our motor to run in its optimal RPM, while giving us maximum propeller RPM.