The following template can be printed and traced onto the material you are
using for a hub. The small wire holes around the edge should be 1/16" dia,
while the center hole depends on your your method of mounting the wheel.
The method described in this article calls for a 3/8" dia. center hole.
The distance from the center point to any corner should be about 2-3/4".
If your printout is far from this dimension, you can use a ruler to draw lines
from each corner to the center point, then mark new corner points at the
correct distance and redraw the triangle.