Rotary Drill Bit Holder

It can hold the following diameters:
Ø 1 - 1.5 - 2 - 2.5 - 3 - 3.5 - 4 - 5 mm

Hardware required:

• 1  M3x20mm screw
• 1  M3x10mm screw
• 2  M3Sx4mm threaded inserts
• 3  6,35x10,3mm compression springs

The threaded inserts have to be put in place at both ends of the shaft: 

The springs have to be placed in the base with the pins laid on them:

Last things to do:

insert the shaft in the main body and make it align with square fit on the base (the flange of the shaft has to be on the top where the selector will be) and screw down the base and the shaft using the M3x20mm screw. 

screw down the selector on top using the M3x10mm screw, try to rotate the selector a bit if it's not aligned with the sector below, the right alignment will have the selector window perfectly centered on a sector (it could be any sector, not necessarily the lock position).