We wrote a short .scad script for the open source software [OpenSCAD](http://www.openscad.org) to facilitate 3D design of laboratory racks used for 3D printing. It is nothing special but very useful if you have vials which wouldn't fit in any rack and don't have the time to design a 3D model from scratch! Just download the script here or at GitHub (https://github.com/vektorious/rack_designer) and try it out! In the script there are four rack parameters you can set: bottom thickness, diameter of vials, minimum distance between holes and the wanted rack dimensions. After rendering your model in OpenSCAD you just have to export it as .stl file and print it with your 3D printer. We plan to further optimize the script and run it online to implement it in this website. Feel free to send us any comments and requests via Email or directly on GitHub!