Getting a late start to the log... You've missed all the design steps thus far. I've really struggled with designing a case that could be 3D printed and easily assembled and upgraded. This is the first draft printed in 3 pieces because of the Z axis limitations of my good printer. Experienced some warping and corners coming off the bed... Need to learn more about how to go about designing for 3D printing and DIY assembly. Got any tips?? 

For now I'm joining them together into a monolithic piece of plastic. The LCD will be VHB taped to the case. The Orthopi keyboard will drop in and sit on resin printed stabilizers/supports. See what the glue looks like in the morning. If it's a total fail then I'm back to the drawing board in Fusion 360 and/or fighting my printer.