Not long after that interaction between me and them, they started selling commercial license for their models. There was a designer that I used to print models from, but I no longer do, because of exactly that. That said, if the designer specifically disallows this interpretation, then it's generally accepted that it's uncool to disregard their interpretation in favor of your own. Some designers disagree with this interpretation of the non-commercial license, which happens to be open to interpretation. Download your favorite STL files and make them with your 3D printer. That's not the same as me printing a bunch of them and posting them up for sale somewhere. Discover 3D models for 3D printing related to Slot Car. They will be paying me for my printing services. We use an analytic and organic approach to every design. We create designs that are unique for the hobby by maximizing creativity and the engineering properties that 3D printed technology presents. If someone wants me to print a file that has a non-commercial license, I will. CG Slotcars creates well designed 3D Printed slotcar chassis. As there are many such services online, I have no problem providing the same service. One of the aforementioned gray areas is payment for printing services. If both parties are happy with a deal, who else is to say anything about it?