A simple turkish spindle that spins fast, is well-balanced, and has a nice sustain. It has 75mm (3") arms and about 90mm shaft. It features a tapered octagonal shaft which locks both arms together and minimizes issues with printing when done without supports.
This spindle probably should not be scaled or at least not much because of how the clearances will scale. A 100mm has been published and a 50 mm version of the spindle will be published shortly.
Using 40% fill with 3 shells results in a nice weight, 13.9 grams.