Customized version of http://www.thingiverse.com/thing:44815
Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing\_id=44815
Using the following options:
margin = 0.1
diameter = 18
$fn = 50
groove = 3
edges = 2
weight = 10
type = 0
cursor = 100
The author marked this model as their own original creation. Imported from Thingiverse.