My niece AVA is the namesake and chief beta tester of these gear toys as I develop a series of them, aimed at kids from two to 18. AVA's Gear Toys, a numbered series, were popular enough on Thingiverse that I realized I had something going here and it was worth developing.
At the moment I am working on a robotic arm based on Gear Toy 2, which is based on Gear Toy 1, and so it goes. You can print out whatever toys are appropriate for your kid's ages and development depending on their level of interest.
Someone said "Kickstarter" and I suppose such things are possible - really I just want to have fun making cool stuff though. I don't want to run a business. In fact, I have found that doing grown-up things spoils the fun. Better to stay in the moment and keep on truckin'!