Stackable, customisable rack for lab tubes. Specify tube diameters, heights, and separation distances, and the OpenSCAD code will do the rest.Have you ever wanted a stackable tube rack that stores 4 1.5mL tubes and two rows of 8 400?l tubes? Now you can create your own stackable rack, where the hard calculations are done for you. Given tube specifications and tube order, this OpenSCAD code will automatically create a stackable rack that you can print out and use. Print v2 if you don't want tube supports (make the tube stand about 1/3 of its height above the rack), or v3 with supports.