On the inside of the box, five block magnets
were glued to the bottom with UHU MAX REPAIR
They will be the collectors of the needles.
I raised the bottom with plywood scraps just enough to have the mounted magnets barely touch the inside of the cover, in order to draw in the needles well.
The cover of the box, that is closer to the floor when in use, does not hold any magnets.
So, when you open the cover, the collected needles will be out of reach for the magnets and will be released without touching them.
A washer and a cube magnet
are used for box closure.
Instead of an aluminum box, you could also use a plywood box, a plastic can or something similar.