I'm using it every day and it's like new, no problem with pla, because the atom's cap is fixed in a very thick piece.
You will need:
6 or more magnets 3x1mm
1 switch 16mm
2 battery contact 11x12mm
Probably you will need to adjust the cap hole, because i ve used an home made steel cap of 18mm with 510 connector.
I've designed this with Fusion360, if you need some info or help feel free to contact me.