for adding Raspberry Pi later

added a knock out cover if your not ready to add Raspberry Pi quite yet but want rear mount board you can run just the board so the cooling fan works

https://www.thingiverse.com/thing:4441076 presented a thumb screw to replace the wing nut on the front-left corner of the BIBO bed. It is too wide for the other two positions.
I have created a smaller version to fit the right-front corner and the back-center.

A M3-.50 nut is required.