I have made a simple case for my deburring tool that fits with the gridfinity system. I designed this so that it only uses the standard 6x2 magnets. the magnets are not the strongest but they hold on tight enough. The magnets need to be glued. 

some specs. 

• case size: 2x4x4U ( 83.5 x 167.5 x 28 mm)
• inner tool hole size:  25 x 157.5 x 21 mm
• magnet holes are 6.5 x 2.3 mm
• 17 magnets total ( bin + lid )
• holds 9 reserve tools (probably more but did not tested magnet strength with this)
• printed at 0.2 mm but you can choose for yours
• no supports needed

Don't mind the holes in the lid on the pictures. I glued the magnets wrong the first time. So don't make the same mistakes as me, make sure the polarity of the magnets are right.