Here are the photos of my printer bed. The first shows the plywood, PCB heater and borosilicate. The plywood is screwed to the drawer sliders, and everything else is held in place loosely by some 3D printed clips (seen at the four corners). That wasn't sufficient so I used two binder clips on the right side to hold everything more securely. The second photo shows PCB heater with the glass removed, and the third photo shows the underside of the PCB heater. I don't recall seeing any other printers with this exact setup for the bed, but since Robo3D loosely calls everything an R1, it's hard to distinguish versions. Any help is appreciated.