Bit holder for 12x hex bits. My problem with other bitholder designs on Thingiverse was that they were either too stiff, or that bits kept falling off. Most commercial designs don't have these problems, but have a complicated full enclosure with live hinges that break too easily. I fixed these shortcomings by using several design features: * separate 'springy' clamps to hold each bit * a rotating clip that secures all bits from falling off, even when this thing is seriously rocked. * the hinges are made of two sping-loaded M4 screws The hexes are fairly stiff when printed in PLA 100micron on my UM2.
Your experience on other printers may vary, so i included the Rhino .3dm file for you to edit and remix as you want. UPDATED v0.12: * introduced variants for spring washers ("f" variant) or 3d printed springs. * introduced variant with clip ("f"variant) or without ("h" variant * made a video:  https://youtu.be/OAvfz_vsHrU