I designed A Case to house your BigTreeTech Pi while being connected to an 2.5 inch SSD drive. It also features a Bezel that houses the BTT TFT35 spi for Klipperscreen which you can connect directly to the BTT Pi. The model is designed in such a way that you can print it on any 235x235 printer like the Ender3. (The Bezel is designed out of two pieces)

The Bezel hides the USB Cable that connects your printers mainboard to the Pi so no need to replace the housing of your mainboard for that. (make sure to use a usb cable that doesn't have a "long" USB connector on the mainboard side otherwise it will not fit under the Bezel or you could damage your USB connector on the mainboard, the Biqu stock micro USB cable doesn't fit for instance) Best is to use a cable with a Square connector on the mainboard side. If you do want to use the stock Biqu cable or an other cable with a "long connector" and/or want to be able to use the Micro-SD slot without removing the Bezel, I added a model for that. In that case print "Bezel left Cable and MicroSD access.stl" instead of "Bezel left.stl".

The Case Cover has a Fan duct that can accommodate a 40x40 fan to cool your BTT Pi. When using a standard 5v fan it can be directly connected to BTT Pi's dedicated Fan connector and be controlled trough a temperature Fan in Klipper.
Make sure to position your heatsink maximized to the front (almost against the Ethernet and USB connectors) to make sure it will not run into the Fan.

The Bezel also features a slot that can house a 10mm wide LED strip over the full length of the Bezel. When used the LED's will shine trough the Bezel, a neat way to add LED status indication to your printer. (see picture)

I did not test this but I presume that a Raspberry Pi 3 should also fit since it has the same screw hole placement as the BTT Pi. Other Raspberry versions should also fit but will need some small modifications to the "Pi to SSD Mount". Using a Raspberry instead of the BTT Pi would also mean that you need to find a way to connect the TFT35 spi to it since you wouldn't have the dedicated connector for it like the BTT Pi has. The same goes for the connection of the Fan.

Make sure to connect the Left and Right Bezel to each other using two standard bolts and nuts while aligning the front of the Bezel parts (the left parts falls 1mm a short on the back, this is to take the 1mm thick sheet metal of the mainboard housing into account).
When installing make sure to start with the case using a T-Screw in the back and only the upper right screw (the one that was holding your old lcd display) on the front, followed by putting in your SSD and BTT Pi. You can run your cables trough the hole on the back left of the Case and trough the front. After this place the cover with the Fan already mounted and fix it by running screws to the four screw holes. Make sure to put in the TFT35 spi before mounting the bezel to your printer. The model accommodates holes for your screwdriver to be able to screw the TFT35 in place. Mount the bezel by screwing in the two screws on the top of the bezel fixing it to the case. If you like you can add the second screw on front right (the other screw for the old lcd). You can do so by using a small bit or screwdriver from the bottom. This can be a bit fiddley and if it is giving you a hard time just leave this screw out since it doesn't influence the overall strength of the construction. Do not forget to put in the two screws on the far left of the bezel.

When you look closely to the pictures of my end result you will find out that the two hooks locking the SSD in to place are missing on the case. Also the "BTT Pi to SSD Mount" is not a complete clean fit. This is a result of not taking some margins into account when drawing the models. Please rest assure that I updated the models fixing these little error's but since I could easily work around them I decided to make the environmental friendly decision to not reprint those parts.

If you are going to use this model I would really like to read about your findings and see your end results, so please take the time to write down your findings and upload your pictures ;).
And if you really really really love the model you are free to buy me a beer trough Patreon if you want ;)