SNAP Rack: Simple Conical/Falcon Tube Rack

A modified version of https://www.printables.com/model/878701-modular-test-tube-rack-iso-41422002 

I found that the circular holes were too difficult to print and the spacing of the tubes was too close. I changed the larger holes to be octagonal so that they can be reliably printed w/o supports. I've also uploaded an F3D file so that the hole sizes, numbers etc. can be changed to suit any needs. The .3mf files uploaded have two sides which fit 15ml Falcon tubes, 1 side for 50ml and the last fits 1.5ml microfuge tubes.

There are notches on the tops and bottoms so that they can be snapped together to form large tube racks of any configuration. I found that very light scrapung with a swiss army knife of the underside of the bottom notch cutouts makes them fit together perfectly but your printer might be tuned enough where this is not necessary. 

Included in both the .F3D and a separate .3mf is a shelf which can be slotted in to the rack to raise up the 15 and 50ml tubes. This is optional and not necessary for the structural integrity/rigidity of the model just a convenience since otherwise those tubes end up being too low and falling through the holes for the tubes on the opposite side of the rack.