"We had a car do this exact same thing [slow down in the finals]. It was traced to the paint getting hot(?), sticky(?) and twisting at the contact point of the wheel to body. It was a pretty yellow paint that showed signs of smudging and twisting when I did an after race inspection. Even though it [the paint job] was done many days in advance of the races. We no longer paint behind the wheels and just press graphite into the wood using a lot of hand pressure pressing a spare wheel against the body while turning the wheel and adding the graphite."
Editors Comment: Likely enamel paint was used. Enamel paint has a long cure time (and stays sticky until it cures). I like to use lacquer paint, which dries hard very quickly.
If you are planning a race and are not required to use a specific kit type, our MV Basic or Wedge Car Kit are just what you need. These attractively priced kits are equipped with:
The existing slots are defective.
The builder wishes to change the wheelbase by cutting new slots on the opposite side of the block.
The builder wishes to build two cars from one block by cutting new slots on the opposite side of the block.
Use the Pro-Body Slotter on the pinewood derby block before cutting or shaping the block.
When placing the tool onto the block, orient the set screw on the side of the block opposite the pencil marks.
Keep the set screw on the same side of the block for both cuts.
Use even, gentle forward and back sawing strokes.
Make sure to stop when the saw blades reach the bottom of the tool.
For an extended wheelbase, position the slots at 5/8 inch (actually I prefer 11/16 inch) from each end of the block.
After cutting the slots, use a Pro-Axle Guide to insert a spare axle into each slot position, then twist and pull it out with a pair of pliers.
When painting, either mask off the axle slots, insert a spare set of axles into the axle slots, or better yet, use a Paint Stand.1
| Pro-Body Slotter
The car looked like a dud but was really a ringer - block hollowed out and back-weighted. Prepped wheels/axles, etc. You would need to inspect the car (check balance point, check wheels, etc.) to know for sure.
The car was a fluke. There are cases were a car makes it down the track without touching a guide rail. When that happens, it really speeds up the run.