@vicious1, just some thoughts, not about Licensing but more on get some money back for your work…
When it comes to make money around a free project it almost always turns around the associated services.
Premium support, video formation access, webinars, all that can help consumers to “masterize” the product.
I think there is a lack of offers when it takes to run a CNC, at least 3 that could lead to premium services:
The build :
I found the documention very complete and i didn’t encoutered difficulty on my build.
But some people might prefer step by step videos with explainations, maybe a time payed access to build video library could help you making some money.
Troubleshooting :
Small recorded sequences of most common issues and solutions to fix it.
Do making things :
Last year I subscribed to wood working online lifetime formation of a famous French wood worker, he has a lot of projects for beginners to confirmed and you can buy for the project you want(build a sheld, a workbench…). Video are great quality and the content is very rich, each formation is about 60 hours+ of videos. He deliver the plan for a project (pdfs, sketchup) and explains it in the first course.
He also offers dedicated forums for the payed “students”.
Learning with a goal is easier, and the A to Z project formations are just, in my opinion, awesome way to onboard free user to pay for something that worth the value as they will learn by being leaded by a professionnal/passionate/expert…what ever you prefer to call yourself.
I paid 400€ for 2 of it’s formations without any regret.
Now about CNC machining, we do have lots of sources to find objects/SVG, DXF we can work on in a CAM Software.
The thing is that software factory is not an easy part and we have seen numbers of people, on various cnc forums, that loved to build their open source CNC but then give up or get to much lost on how to use it and ends to try to sell there cnc.
Not enough time to get involve or not enough inspiration, we often says you are limited only by your imagination, can be frustrating for someone that lacks of imagination.
I think a premium access to step by step didactic videos of a small panel of project would be just awesome.
Projects declined for Primo and LowRider, and with 3/4 skill levels.
Small format of videos( 10/20 min max) and several for a project to cover it all, explaining pockets, tabs, direction of maching if the project need it… every thing you know without having to ask yourself but that could causes pain to bebinnners.
I know it’s a hudge work, but starting low and growing it months over months you could build something cashable.