Parametric Test Tube Rack

thingiverse

A versatile test tube rack engineered to accommodate nine test tubes but customizable to hold any number that can fit within a rectangular frame. This design prints reliably in PLA; however, it may encounter issues during autoclaving when temperatures reach 130C. Several prototypes were printed using Polymakr PolyFlex, a material stronger than NinjaFlex with excellent heat resistance up to about 200C, rendering it suitable for the autoclave. Note that attention should be paid to the printing material's suitability, especially in laboratories handling caustic chemicals or biological samples. I designed this test tube rack after experiencing problems with existing racks, which were too tall for centrifuge tubes, prone to breakage, and costly to replace. The design is based on an affordable commercial model priced at $15. To build upwards without hindering printability or increasing the cost, various construction methods were explored before arriving at the final result. Users can easily remove bridges from the design by setting "connectors=0" in the .scad file; this modification should work with most printing materials, but adding connectors enhances strength and durability.