Customized version of http://www.thingiverse.com/thing:50223

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=50223

Using the following options:

gh = 10
gd = 22.5
ggdt = 1.5
Dcut = no
sd = 6
nf = 0
nt = 18
$fn = 12