SO here is the information for making 3D gears that all fit together. I used Sketchup for the design. All the gear convexities and concavities are 3-inch half-circles.
6-Spoke Gear
12-sided circle
6-inch radius (12-inch diameter)
Rotated 7.5 degrees
12-Spoke Gear
24-sided circle
12-inch radius (24-inch diameter)
Rotated 15 degrees
24-Spoke Gear
48-sided circle
24-inch radius (48-inch diameter)
Rotated 3.75 degrees
Rectangular 14-Spoke Gear
12- by 24-inch rectangle
6-inch radius circles at ends
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