The axles are dowel rods that I bought because they happened to fit the bearings that we had. The other flat pieces of wood were designed in illustrator and then cut on a laser cutter. The laser cutter is an amazing tool to make the parts of this car quickly and easily. If you have one use it. Keeping the car square is very important because the more square it is the straighter it will go making it more predictable and score better. The cross pieces to make the frame are half-inch square pieces of wood. Making these straight and square will make the car go straighter too.