bionik case for the AMD BC250 and ATX Flex PSU

UPDATED: v1.3

• Added alternative fan sleeve for 3x 120mm fans. Use high pressure ones on the front side. I personally use the default 2 fan version, additional fan is not a big impact, but YMMV.

UPDATED: v1.2

• Updated front card mounting hole location for better fit

• Larger screw holes for PSU

UPDATED: v1.1

• No gluing necessary anymore.

• Larger fan opening for the PSU to accommodate a wider range of power supply units.

This is a custom case for the AMD BC-250. I never found the perfect minimal case online, so I decided to design my own. It features ample airflow for air cooling and dedicated clearance for backside cooling options.

The case is designed to accommodate a Flex ATX power supply, a 200x120x7mm backside heatsink, dual 120mm fans, and a power button.

It can be printed on a standard 200x200mm build plate.

I recommend using a 4pin PWM fan splitter or using daisy-chain fans to attach both fans to the CPU fan connector.

The heatsink can be found on AliExpress - Try the following links (choose 200mm long version):

• https://www.aliexpress.com/item/10000050909834.html

• https://www.aliexpress.com/item/32919692329.html

• https://www.aliexpress.com/item/1005010313760253.html

• https://www.aliexpress.us/item/3256810127445501.html

Required for assembly (v1.1):

• 15x M3 (5mm OD x 4mm L) heat-set threaded inserts

• 15x M3 screws (8mm thread length)

• 200x120x7mm heatsink (for backside cooling)

• Thermal adhesive

• Flex ATX PSU

• 2x 120mm fans

• Power button (20mm hole) - You can use 24-pin power switch or make your own

Prerequisites:

• Open up the main heatsink around the central 120mm fan area.

• Trim a corner off the additional heatsink to allow clearance for all backplate mounting screws (check the attached images)

Printing:

• Use PETG or similar for thermal stability.

• Side Covers: Print on their flat side. Regular/snug supports for tabs, on build plate only.

• Main Case: Print both parts flat on its side. Regular/snug supports. Block supports inside screw holes and small features like the straight vent slots, to avoid painful cleanup.

• Fan sleeve: Print on the edge so that the backside mounts are vertical. Use support for the circular fan hole.

Assembly:

• Print all included parts.

• Melt heat-set inserts into side covers. Attach 5 inserts to a single "back cover" and 1 to the "front cover" - match the holes on the case. Repeat for both sides. Insert heat-set inserts from the "outside".

• Melt heat-set inserts to the 3 BC-250 mounting holes on the main case. Insert heat-set inserts from the side of the BC-250 connector holes.

• Attach the main case halves together.

• Attach side cover (backplate side) to the case with screws to hold everything together.

• Attach the 200x120x7mm heatsink to the backplate using thermal adhesive.

• Mount the interior fan inside the sleeve using screws inserted from the inside (look for chamfers to understand where the screws should go in). Slide the fan sleeve on, then attach the outer backplate fan. (Optional: Use an M3 screw to the hole on the side of the sleeve to lock it on place, though friction fit may be sufficient). Ensure both fans are oriented to push air into the heatsinks.

• Install the power button.

• Mount the Flex ATX PSU.

• Install the BC-250 board and secure it. Slide the rear connectors in first.

• Connect all power and signal wiring.

• Attach the other side cover.

• Enjoy.