Here's the preview:
That's the frame from Herpybike, modified to accept a threadless mountain bike fork. I removed the original 1" threaded fork, banged out the headset cups, and re-bored the head tube to accept the cups for a 1 1/8" headset.
For the tracks, I made a pair of track rollers from some scrap plastic. The plastic centers are clamped by the original scooter wheel hubs, which conveniently already have axles and bearings.
The plastic bits were machined on the CNC mill, which was covered in lovely red and white confetti afterwards:
Here's the mostly-assembled track pod. Two aluminum plates space the track rollers and allow the tread to be tensioned. Don't worry, the wingnuts are temporary.
The fork is going to get a ski, and I'm temporarily borrowing the power system from Nick's old 2.007 vehicle, derpscooter. I'm fixing the hall sensor wires, which managed to get caught in the rotor and shredded.
More to come soon.