Grand Prix Racing - How To Make A Fast Pinewood Car

Shine-up the Axles

Burrs may oppose wheel rotation more in one direction.

Removing hub spurs and polishing your axles can cut friction in half when a lubricant is used. Grinding them may not reduce it any further. However, both polishing and grinding require work with a drill, steel wool composite, polishing compound or grinding medium. Gloves come in handy if you do not have a jig to hold abrasive material.

Remove Hub Spurs

Hub spurs are small triangle-shaped "ribs" that extend from the axle shaft to the underside of the hub.

AWANA: There are four on each AWANA kit axle. Most competitors over look them because they are so small.
BSA: No one misses the two large ones on each Boy Scout axle. In some cases, they must be removed before the wheel can even spin!

You can remove the spurs when you polish your axles. Use a file with its flat face against the underside of the hub as you spin the axle according to the instructions for polishing.


Polishing is fairly simple to do. Even if you just use steel wool, some benefit can be gained. The paint section of your local hardware store sells pads for polishing metal. Often they have steel wool fibers in them along with other fibers that help make the surface smooth and even. To avoid ridges and burrs, use a metal or jeweler's polishing compound. If you grind your axles to reduce their diameter, you will still need to polish them.

Time saver
If you must grind your axles to make them thinner, you may be able to save yourself trouble by using a thinner 1-inch nail or a sewing pin. Check your race rules.


In the procedure below, each axle is turned while grinding. This action causes burrs to develop that make the wheel spin faster in the direction of grinding. If you do not use a polishing compound when you later polish your axles, axles from opposite sides of the car will need to be ground in opposite directions. A reversible drill is needed to achieve this.

You will need a grindstone made of tough material. Those that can be purchased for dremel-type hobby tools make little progress on kit axles. Some Grand Prix competitors use high-speed grinders to thin the axle on opposite sides. The axle must still be polished to remove burrs. Mounting must be done with care so an unground edge of the axle makes contact with the bottom, inner surface of the wheel's bore.

Theory shows that thinner axles are probably better than thicker ones only when the wheel bore is also narrowed. Thin axles can bend undesirably.

In order to polish or grind your axles:

  1. Insert the end of the axle into a drill chuck and tighten. Do not put the hub end in a drill chuck.
  2. Put the abrasive material in a jig to hold it, or wear leather gloves and hold it in one hand. It helps to bond the material to a rigid holder for best results.
  3. Apply some of the polishing compound to the axle or abrasive. If no polishing compound is used, set the direction of the drill appropriately for a left or right axle. (See Definitions below)
  4. Trigger the drill and carefully press the stem of the axle on to the abrasive medium, lightly. Care must be taken so it does not race off the medium onto your hand or heat the medium so it burns you. It can be tricky to keep the hub away from the medium so it doesn't cause a jump or excess grinding of the hub.
  5. Move the axle back and forth along its axis on the medium to help even out any ridges that may form around it. A polishing compound helps prevent this.
  6. Polish with successively finer abrasives until your axle is bright and shiny or the desired diameter has been obtained. For a final mirror polish, polish with a lintless cloth and polishing compound.

Take all precautions against injury when grinding your axles.
As long as even pressure is applied along the stem from the hub and out about 3/8 inch from the hub, a good result can be obtained.

If you slope the back of the hub with a small file, don't over do it. Excessive "coning" can act as a cork in the borehole of the wheel and increase friction. On the other hand, a flat back on the hub can be bad if the wheel has roughness in the hub area.


The right side of the car is the right side of the car when the car is facing you front first.

Looking at the axle with the hub end pointed away from you,

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Grand Prix Racing - How To Make A Fast Pinewood Car
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