About this 3D model

I've been playing round with a lot of different build surfaces for my Makerbot 2X. One of my favorites is 6"x10" 1/8" borosilicate glass (McMaster) with .5mm Gino silicone pads between the glass and the stock build plate. With this combination the build surface is way too high to compensate via the leveling screw adjusters. So this is just a simple "Z-clip" that moves the homing location down by .145".