I wanted a safe, discreet place to hide away my Klipper Raspberry Pi in the Ender-5 S1's frame. I love modding my printer but I like it to look tidy and “original” wherever possible. This position is free from collision with any moving parts, and the primary ports come out the side as if they were built in. It also has M2.5 screw holes for a 30mm internal fan, and enlarged header clearance for custom-made header plugs (eg MPU or ADXL).
I would have loved to have the ports coming out the back but the clearance between the z-rods and frame is not wide enough. This should also work for any other printer with a single or double profile channel like the Enders often have, provided you can find a good spot to mount it.
Printing
PET is recommended due to heat tolerance, however I've printed it PLA and it seems to be fine. The photos are using a matte black filament which suits the semi-matte Ender paint quite nicely. No supports are required.
Assembly
No additional parts are required, however it's a bit tricky to install. I'm using the exact part names from the printer's manual for clarity, so it may help to have that open for reference.
If you need to access the Pi again, you can simply remove the right diagonal bracing and pop the top of the case off.
Now that you've reassembled your printer frame, you should re-calibrate your resonances as they may have changed slightly. See my model for mounting an MPU-9250/6500 motion sensor to the print head.
The author remixed this model.