In biological sciences, we use 6 different sizes of tubes for samples. This two part block, is the only block I know of that can accept all 6 types of tubes. I designed it so that I could split into 2 halves to be used as 2 separate racks. I\'m really excited about scientists and hobbyists being able to produce useful equipment at home... provided they have access to a 3D printer.
Tube sizes that it holds include: 0.2mL, 0.5mL, 1.5/2mL, 5.0mL, 15mL, 50mL
The photograph is of other tube holders that are not as versatile. (You wouldn\'t hold tubes in all sides, just in a vertical orientation. Horizontal tubes are displayed for demonstration purposes.)
3D print SB_SMside and SB_LGside. Use either the igs or stl files. Hold tubes.