So I’ve been using a ball mouse on one of the PCs, just to honor the old days, and it’s always been somewhat hard to roll horizontally.
I opened it today thinking that it might not be just dirt in the whole hollow point, but just the rolling bars that transfer the rotation to the optical sensors. One, that was diagonally positioned and I don’t think is really anything at all, has a very thin layer of this greyish stuff, the smaller one for the vertical movement doesn't even seem to have the surface for such a layer. The thin and wide one that is for the horizontal motion has quite some of this, mostly towards the middle (the edges are pretty much clean), and I am fairly sure there is an irregularity in the thickness on this.
My guess is it’s dirt that piled up along with residue from more liquid material and formed this pigment of sorts, slowly being transferred from the ball to the bars.
However I am a bit anxious that it might be there on purpose to create friction, and that removing it might just make the ball slip on the sensors and make it worse - I don't also know if that would be reversible.
So does anyone know of this weird material, and whether it’s safe to just remove the whole lot of it?