Just in time for Valentine's I've updated my Heart Gears. These use my new snap pin library, so they print more reliably and are much easier to assemble. I've also included three different gear ratios so you can choose how much frustration you wish to impart.
Assembly instructions can be found in this video: http://youtu.be/O-qwmRwOpFQ
Alternate instructions are here https://jig.space/viewer?jig=427, courtesy of greenlig. Pretty cool system for making interactive 3D instructions - check it out.
I didn't make this design Customizer-friendly, because there aren't really changeable parameters. However, the OpenSCAD file has been rewritten and greatly simplified to make it easier to cut gears out of your own shape. I'm always excited to see new derivative gear mashups.
Hopefully the video makes assembly pretty clear. I always recommend greasing the pins to keep it turning smoothly without squeaking. I use white lithium grease, but anything that doesn't melt plastic should work.
The heart plates are named by their gear ratio, so 1-2 is 1 : 2, etc. 1-2 has a period of one revolution, while 2-3 is two and 5-6 takes five revolutions, so don't give up. If you need the parts separately, many free mesh editors and slicers can separate plated parts. Or you can export them from the OpenSCAD script.