A simple case for a buck converter from Amazon: https://www.amazon.com/dp/B081N6WWJS?psc=1&ref=ppx_yo2ov_dt_b_product_details
Designed to use 8mm m2 socket head screws with CNC Kitchen heat set inserts.
No supports are needed and the base has a sacrificial layer, you may need to play with the layer height to get it to print correctly, or modify the STEP file
The author marked this model as their own original creation.