I make thingies. Mainly designs for parts to upgrade 3d printers, but the occasional Trombone design here and there for good measure. Right now I have 17 designs for 3d printer upgrade modifications released publically to as Open Source designs. Anyone can use, sell, modify, upgrade, retrofit etc. those designs as they see fit, the only license requirement that I put on them is that they attribute the original idea to me. http://www.thingiverse.com/piercet/overview
I don't expect to ever see a dime from any of those designs parts. They are more to advance the science and accuracy of various 3d printer motion control systems, to get my name out in the community as a designer, and to show people what I can do from a design perspective.
I uploaded most of them when thingiverse was an independent website repository. They have since been bought out by Stratsys and which changed their license model for hosted files retroactively for all models uploaded to allow them to print and sell any uploaded piece as they see fit without assigning attribution to the original designer. They have actually already taken an entire printer assembly piece from one of the people who posted design files to thingiverse and incorporated it into the makerbot printer as their own design. What annoys me no end is that they then patented that piece. The designer who created it put it out there as an open source attribution license as well. He wasn't expecting to see money for it either. but he also wasn't expecting some other company to take his design and basically lock him out of legal control of it. The patent shouldn't have been granted given the pre-existing open source copyright license, and there is currently a court case theoretically pending over it just due to the legal precedent. I've actually not uploaded my trombone design there even though I think it would be quite popular specifically because of those license shenanigans
The problem with all open source licensing, is how does the desiger / inventor make money? If you have your own printer company, than releasing your designs open source (like lulzbot does) is a brilliant move from a marketing and brand loyalty perspective. The patent process theoretically gives someone who designs something but doesn't have the desire / means to produce it a way to make money. so many of the patents issued these days are for absolutely stupid blanket overly broad sue licenses that it makes the whole system annoying and cumbersome. Licensing seems to be a theoretical replacement, but then you start putting digital rights management DRM crap into models in order to sell them. I could upload something to shapeways,com right now to sell under license with them actually printing it, but whats to prevent them from changing their license model the exact way thingiverse did. I can always remove my models at that point, but the damage is already done by then too.
Then you have the "e-book repository" style pay per download model repositories. I can upload something there, charge $0,25 - $1.00 per download, make 75% of that charge back (the rest goes to the host, etc) and theoretically make money that way. The fees are low enough that people are willing to buy the legal copy rather than just looking for an illegal one. so it seems to work. I have existing models with over 9,000 downloads, so it's not unreasonable to assume I might be able to put some models up and sell a few thousand of them, depending on the content and complexity, etc. That still doesn't protect me apparently from someone just patenting one of my designs, despite the rather obvious "prior art" piece that goes along with that. Probably a pretty easy lawsuit to win if that ever happened, but against a large company, who has time or money to go that route?
I dunno. the whole system is broken at the moment, and could probably be fixed pretty easily with a few law chages that have something like a negative infinity chance of ever actually happening.