Made an enclosure for the 50 cent DC stepdown converter. You can use 12/24V from your 3D Printer's PSU or Car's output and this converter would output to 5V.
It can be used to power up Raspberry Pi for your Octoprint or Pi together with LED lights as it has two USB ports.
I'm not affiliated with the product (converter itself), just made an enclosure, so a problem is solved under a dollar without having to use additional AC/DC power adapter and you can chuck into your 3D printer's mainboard bay to hide it or just leave outside.
It's a really common step down converter on various ecommerce sites, not sharing any links.
Including FreeCAD design in case you wish to modify:
Bill of materials:
2 heated inserts
1 6-40V to USB 5V DC-DC stepdown buck converter
0.20 or lower is fine. 0.12 if you want to see the nice fillet/chamfers. I put a chamfer as countersink for the screw hole however it's for M3 screws only. I made hole size 3.5mm so I could use brass heated inserts. They can cost 5c or less each if you buy in pack of 100s. Feel free to modify the hole down to 3mm if you want to directly screw into the holes after tapping (so plastic won't break.)
I didn't put any cable strain relief for input as it will be up to you to use what kind of cable with what kind of relief. For my own use case I pulled cables through first, then I crimped them with mini ferrule tubes before screwing them into terminal of the buck converter board.