Holds 8 tubes and I've tested the diameters for standard 1.5mL and 2mL microcentrifuge tubes. Feel free to remix and modify. Enjoy!
P.S. Here's the TinkerCAD listing if you wanna edit directly:
https://www.tinkercad.com/things/ibYT7RmGHpb-tubeviewer-mk1
The author marked this model as their own original creation.