Two adafruit feathers, some small components and 18650 holder

18650 needs spring. I was not able to tested. 18650 fits fine. Use AA batteries springs to connect 18650.

I have tested feathers, usb hole and screws and the lid. You will need 2.5m screws with 3mm depth to screw the feathers.

Made with FreeCAD-0.20.2. After some months I re-opened the file and had some fillet on wrong positions - on holes for screws. Maybe you experience the same or other bug.

Printed with PLA in white color can see the led's blinking.

Many things are parametric, but NOT all goes well if some values are changed. My bad design? FreeCAD bug? I don't know. Either way, if you want to change dimensions, try to change some spreadsheet values.