Pergo's ROBO3D Bed Extension - Flat Bottom for 10 1/16" Glass Bed

Remix of Pergo's ROBO3D bed upgrade - made the bottom flat for easier printing and slightly increased the spacing for the bed. My glass is non-stock and slightly oversized from the original (about 10 1/16" wide). This change fits cleanly.

Fairly specific to my setup, but may be helpful to someone.