Pinewood Derby Car Axle Keepers

When using the provided slots in a derby car, the chances of creating a blowout or having an axle loosen up and fall out is pretty high. I see a lot of people using glue to hold the axles in. So I designed these axle keeps which are similar to some off the shelf products. They use 5 #6 3/8" long screws to hold them in. You can pick a 12 pack of these screws up at your local Home Depot for a $1 or so. (UPDATE: I found some #4 1/4" long slotted screws at Menards for $0.40 for a bag of 8. These