This parametric Fusion 360 model allows you to tailor bit storage to your specific requirements.

The main parameters are as follows:

• qty_x - number of bits in the x axis
• qty_y - number of bits in the y axis
• bit_width - the size of the hex bit with some tolerance added in (default 6.65)
• margin_x, margin_y - defines the border size (default 3mm)
• separation_x, separation_y - defines how far apart the holes are placed (default 2mm)

To access parameters, choose Modify>Change Parameters from any modelling tab.

The parameter bit_width governs how loose or tight the fit is for the bits; the default value works for me with my setup.

Note - Fusion is a bit funny about some parameter changes and fails to redraw the model correctly. In this case use CTRL-B or ⌘-B to recalculate.

Also be careful not to overtax Fusion's calculation engine - 20x20 is more than enough to bog it down, although it will still work.