Eppendorf tube 1,5 ml rack (+ eppendorf FreeCad model)

This Eppendorf/Centrifuge tube holder is used for packing under nitrogen - flow of nitrogen goes into a downward-facing funnel. I put my samples into the tubes, put them in the rack under the funnel, wait for a few minutes for nitrogen to displace air from the tubes Then I close the tubes thus packing my moderately air-sensitive materials under nitrogen.
It was designed in FreeCad (see the file). In order to save material, use 0.1-0.2 infill settings.

Good luck