6-wheel drive with 8"/7.65" AM pneumatic wheels 9.018" apart. Used #25 chain on 16 tooth sprockets direct C-C +0.018". Powered by a 4 CIM WCP SS gearbox at 15.4 fps. The design originally called for 13t pinions on the CIMs for 17fps instead and no center drop. The frame was basically a square with some cutouts, and was very robustly built excepting the use of 90* sharp gussets instead of triangles on the corners. Fortunately, they held all season. 5/32" rivets everywhere. However:
We experienced problems with the two mounting holes for the CIMs bleeding into each other enough that the 13t distance got way to close to the 12t distance, causing huge lockup of the gearbox until we swapped to 12t pinions. I think I sent an email to WCP about it; making the two different mounting holes actually separate from each other would have been really helpful on their part. We also had to add a 3/8" center drop later in the season. We didn't break any chains, but we did throw one at SVR due to bad assembly of the chain run pre-match (badly misaligned).
Overall, it worked great, except we could beach on the moat. Making the the DT not beach in design is something we can practice in the future.
