A 3x3 gridfinity tray for holding 125mm sanding pads.

I attach two models, one is 3u tall and holds between 10 and 20 pads depending on the grit (lower grits are thicker) and another one that is 6u tall and holds between 25 and 50 pads. Both have a notch on a corner to stick your finger and grab the pads easily. Although if you use mesh pads, you can store them upside down and just press the sander to attach them right from the bin.

I attach the fusion 360 file in case you want to make even taller bins.

Note: Since a 3x3 bin is 126x126mm, this is a snug fit for 125mm and it may not fit 5" sanding discs if they really are 5" (~127mm). Please measure your sanding pads before printing.