Customized version of http://www.thingiverse.com/thing:5123

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=5123

Using the following options:

thickness = 2
a5 = -20
a4 = -18
a3 = -22
a2 = -12
a1 = 12
inner_diam = 10
w5 = 3
w4 = 5
w3 = 8
w2 = 12
w1 = 15
l5 = 15
l4 = 10
l3 = 10
l2 = 20
l1 = 25
height = 3