Step 7: Add the back cover
Place the assembled frame on top of the plexiglass or Lexan sheet. Using a screw or other primitive object, scratch a mark around the edge of the frame.
Cut out the backing with a hand saw, table saw or the cutting implement of your choice. Line up the cut piece on the back of the frame and drill six pilot holes through the backing material and into the back of the frame itself. It is now ready to be closed up once all the electronics are in place and functioning.