Summary 3-D printable open source desktop nutating mixer, which provides a fixed 20° platform tilt angle for a gentle three-dimensional (gyrating) agitation of chemical or biological samples (e.g., DNA or blood samples) without foam formation. The custom components for the nutating mixer are designed using open source FreeCAD software to enable customization. All of the non-readily available components can be fabricated with a low-cost RepRap 3-D printer using an open source software tool chain from common thermoplastics. All of the designs are open sourced and can be configured to add more functionality to the equipment in the future. It is relatively easy to assemble and is accessible to both the science education of younger students as well as state-of-the-art research laboratories. Overall, the open source nutating mixer can be fabricated with US$37 in parts, which is 1/10th of the cost of proprietary nutating mixers with similar capabilities. The open source nature of the device allow it to be easily repaired or upgraded with digital files, as well as to accommodate custom sample sizes and mixing velocities with minimal additional costs. Original designs by: Dhwani K. Trivedi Full instructions for assembly: Dhwani K. Trivedi and Joshua M. Pearce. Open Source 3-D Printed Nutating Mixer. Applied Sciences, 2017, 7(9), 942; doi:10.3390/app7090942 https://www.academia.edu/34589801/OpenSource3-DPrintedNutating_Mixer FreeCad Files to customize: https://www.youmagine.com/designs/open-source-nutating-mixer More open source scientific equipment at: http://www.appropedia.org/Open-source_Lab