Video of the Vortex Paint Mixer in action!
This is a remix made of this thingi https://www.thingiverse.com/thing:1660555 lots of info found there. This vortex shaker is more of a paint mixer for using Tamiya paints, Vellejo paint bottles or any paint bottle with the same size's
140mm PC fan
A balance weight to mount on the PC Fan blade
4x Springs i use 11mm Outer 9mm Inner Dia and 70mm long (RC Car Crawler Springs)
4x M3x45 screws
6x 10x10x2mm Magnets
12v DC power
DC Power Socket Jack Plug 5.5mm
On/Off Switch or a Toggle Switch
Some power wire 15cm should be enough
Optional a Fan Controller so you can change the fan speed if you want to
Soldering Iron and solder
Optional a drill with a 2.5 and a 3mm drill bit
All parts and the magnets can be glued with CA glue if you print the parts with PLA filament.
The springs i use where from a rc car that is discontinued for a long time now (Venom Racing Creeper) http://www.rcgarage.com/venom-creeper-crawler-shocks-1-pair-red-ven-8385re.html but if you look at the RC Car brand 'Axial RC' you can find long size springs they don't need to be stiff or soft they only need to 'wobble' the plate holding the paint.
Maybe you can even use some fuel line or a hose for this part.
For example (the size may be different!)
Axial Racing AXIC1297 Spring 14x90mm 2.25 lbs/in - Green (2pcs) (Blue Springs)
Hot Racing 120 Rock Crawler Dual Rate Springs STD120MR128