for this you need:
a craft cutter which works with Make the Cut and can accept accept arbitrary vector art. I'm using a Cricut with updated firmware (before the lawsuit
happened). See this instructable
for how that worked.
some sheets of type 6 plastic, aka shrink plastic or "Shrinky Dinks"
"make the cut" software, or similar
a crisp image of the gear you would like to replicate
an oven. (I use a toaster oven dedicated to baking plastics like shrinky dinks and sculpey).