PRO Wheel Mandrel

What is a wheel mandrel and what is it used for?

The PRO Wheel Mandrel is used to hold a pinewood derby wheel in the chuck of a drill or a lathe so you can secure the wheel and spin it at a high speed. You can then gently apply a very high grit sandpaper to the wheel to shave down high spots and imperfections that make the wheel out of round.

You can use the mandrel to polish or machine the wheels to true them up so everything is perfectly concentric to the wheel bore, or center of the wheel.

How to use a Pinewood Derby Wheel Mandrel in 2 steps

STEP 1: Secure the mandrel by inserting the shaft into in a drill press, dremel, or a drill.

The mandrel screw has a beveled face to ensure that the wheel is centered on the mandrel screw. For best results, wiggle the wheel slightly as the screw is tightened.

Tighten until the wheel is firmly in place, but do not over tighten as the wheel could be damaged. This is especially important for wheels made with a softer plastic, such as those supplied by Awana Grand Prix.

The face of the mandrel has a step-down to allow mounting BSA Cub Scout wheels with the spokes facing towards the mandrel. This simplifies polishing the inside edge of the wheel.

STEP 2:Touch the wheel lightly with high grit sandpaper mounted on a sandpaper block.

A sandpaper block insures that the sandpaper is perfectly flat.

Using a Wheel Mandrel will make your pinewood derby car faster!

  • By removing imperfections, your wheel will be perfectly round which makes it spin smoothly, making your car faster.
  • In addition, removing even small amounts of plastic from your wheels will make them lighter and a lighter wheel requires less inertia to spin, making your car faster.