This design was inspired by member Hexagon's design found here.

I decided I didn't like the orientation of the original design and I had to scale it to fit it on the bed of my PrintrBot Simple Metal. So I decided to redesign it from the ground up.

To print this on a PrintrBot Simple Metal you will need to disable the Auto Levelling function to make use of the entire print bed. This can be done by simply commenting out the line "G29" in the start gCode. If your PrintrBot was assembled well and has not been damaged this shouldn't impact the print greatly.