Simple Christmas Pyramid

- another christmas / winter themed design
- modeled in fusion360
- inspired by traditional german christmas pyramids (https://en.wikipedia.org/wiki/Christmas_pyramid)
- simple, minimalistic approach
- powered by rising/moving air from a heater / radiator / etc
- do not use open flames!
- uses a small magnet and some steel balls as a rotational bearing
- there are model versions for 13mm steel balls, and 1/2" steel balls ("_inch")
- the arc base structure consists of 3 parts glued together, make sure to sand the contact surfaces flat to make the assembly easier
- ther are model versions for D10xH3mm and for D8xH3mm cylindrical magnets
- you need to print "base" 3 times and one "bladering"
- model units are [mm]
- https://youtu.be/Eks_HvOsT2U

***Edit 20171203***
- after a few weeks, the steel balls creating the rotational joint seem to have flat spots which increase friction and stop the rotation of the bladewheel
- I added a very small steel ball (one from a 608 skate