Look at it go! Although, it still might be A tad to slow for mixing speed paints... On serious note, it's surprising how well a small 6V DC motor can handle this. Still under load (of a dropper bottle full of paint) it can get very hot. 12V DC motors handle the load better and pull less current. But larger form factor makes them less handy in this design. Putting this in a larger chassis would also help with dc motor colling. The big ones usually have a internal fan, but using one with a long shaft, that protrudes both sides of the motor, can have an extra fan mounted on the opposite side to improve air flow. One issue with the cheap DC motor controllers seems to be that they don't limit how much current we pull, they just come with certain grading (up to 2A or 3A and so on). I've "created" (with the help of internet and gemini) NE555 and LM393 based controller, that does the same but also caps the current motor can pull at around 2A. https://www.tinkercad.com/things/8tIQjxC0z1g-12v-dc-motor-controls-with-lm393?sharecode=TGdQJ0ryT5G3Q4cLlrF80FzPYwbttheIweVqDEOHQcc Plus it should be easier to put a microcontroller in between to control PWM and current limit (and other stuff whatever it could be - rotation counter? Spinning programs depending on how old the paint is and how much stirring it needs. Quite useless but could be fun). Also this build doesn't fare well with printed bearings, as they can grind to dust under high speeds. Still it might've been because I've tested them before assembling, and had to hold everything in one hand as other turned power supply knob. Either way, using ball bearings instead works much better. This time only single stage of planetary gearbox assembly is needed, anything above has been putting motors under unnecessary strain. PLA gears also shedding plastic (when paired with 12V DC motor), I might try nylon for the electrified build. #Sharing Makes #Wip(Edited)

Finally, after an unexpected influx of motivation, I've made an update to PaintSpinner - an "Oldham Upgrade" - that introduces a new mechanism to transfer all that axial rotation into slightly different motion, which seems to work well enough to shake and stir paint dropper bottles. https://makerworld.com/en/models/1682616-paint-spinner-aka-vortex-mixer I got the idea from "The Engineering Mindset" YT video about scroll compressors: https://youtu.be/e_4ITFCQvts (interesting watch). This is much better solution with a perfect footprint for this design, compared to ratchet and pinion or different yoke based mechanisms that were either super loud or unwieldy (at least the ones I could come up with). Second most important part of that upgrade are herringbone/double helical gears. I'm surprised how much quieter they are compared to helical gears (it's more noticeable change than switching from spur gears to helical gears). At the cost of even more annoying assembly these type of gears seem to remove most of the locking problems that came with helical gears travel up or down as they rotate, making the assembly work much better from the start. So that's a win, (as long as you gloss over manhandling sun gears into position between the planet gears). (I like how in the video the movement matched shutter speed and becomes all floaty)