BTT Pi4B CB1 case optimized for bridging, with integral supports

The problem I had is that the supports didn't allow for a surface finish that I liked. 

 This Model has integral supports, that need to be popped off when the print is done.  Before assembly.

I optimized the design for printing in a specific orientation  it should import to your slicer in the correct orientation.

This can be printed with no additional supports from your slicer.

The other remix for this model works quite well, but it leaves screw heads raised above the top of the case, and requires longer screws.  I wanted to keep the recessed screw heads, and retain the ability to use the stock length screws that come with the CB1, PI4B.

I also increased the diameter of the inner screw holes, so that they match the diameter of the outer holes, for better engagement of steel m2.5 screw threads.  The little plasic screws that ame with my Pi4B seem undersized, and broke when trying to thread them into the heatsink holes of the original model.

This model requires 4 m2.5x12mm screws for the outer holes,  2 additional m3x12 screws and 2 m3x10 screws for the heatsink.

The .stl files should import to your slicer with the parts already in the correct orientation.  Just in case though, the top half should be printed with the “BigTreeTech” log facing down, against your built plate.   The bottom part should be printed with the large cavity facing up, and the flat surface against your build plate.

Use 0.2mm layers, and the supports will end up with a 0.2mm gap, and should snap off with little effort.   You can use part cooling during the bridging, and should get good results.

This model requires your printer be in a good state of calibration, otherwise the screwholes may be too tight, resulting in cracking.  If your printer prints holes undersize, you can use a m2.5 bottom tap to thread the holes.

Changed to text to make the support instructions more visible.