Clip on sample tube rack adaptor for mixing wheel (16mm clips)

We have limited space (and budget) for additional equipment in our laboratory. I designed this clip on adaptor to fit onto our existing mixing wheels. This saves time loading and unloading sample tubes which can be particularly tedious / bulky when mixing more than 20 tubes on a wheel of this design. 

This was designed for Ratek mixing wheels that are 260mm in diameter with 16mm tube clips, but it may fit other makes/models. 

While not necessary I used some foam to hold the rack into the adaptor while mixing.

The BASE part requires supports due to the offset of the clips from the surface of the wheel to allow the top to wind down. You will need to print two of the KNOB/SHAFTS.

Printed with a customised Ender 3 MAX and a 0.6mm nozzle in PLA 0.25 mm layers, 2 walls with draft settings and it's sufficiently strong.