Creative Commons and selling CAD files

Does anyone have any experience with Creative Commons licences, in regards to selling CAD files?

I want to be able to sell a file to a customer, so they can use it non-commercially; i.e. get it made themselves, but not sell it, nor pass it onto someone else who will start selling it.

There are some options for putting DRM on STL or DXF files, but I don’t like the idea of DRM, and I think perversely it would make certain people want to crack it and copy it. I want to trust that most people would do the right thing but I’ll accept there may be some unavoidable ‘leakage’.

This is what I’ve come up with so far:

“Attribution-NonCommercial-NoDerivs 3.0 Unported (CC BY-NC-ND 3.0)

You are free:

to copy, distribute, display, and perform the work

Under the following conditions:

Attribution — You must give the original author credit.
Non-Commercial — You may not use this work for commercial purposes.
No Derivative Works — You may not alter, transform, or build upon this work.”

The “No Derivative” part I figured is to stop people tweaking a part of the design, then using that as a loophole to sell it on, but I’m not sure if this is actually required. is a similar idea, but anyone can download the files for nothing, and they have a slightly different CC licence:

“OpenDesk is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.

Creative Commons is a non-profit that develops legal and technical infrastructure that maximizes digital creativity, sharing, and innovation.

The terms of the OpenDesk license mean that you can copy, distribute and use the OpenDesk designs as long as you follow two conditions:

Attribution means that you must credit OpenDesk and refer to the designs and any finished products as OpenDesks
Non Commercial means that you mustn’t use OpenDesk for commercial purposes, which basically means you’re fine as long as no money changes hands”

Like the concept, but I think with all Creative Commons licenses you are appealing to people’s better nature. The CC license puts the good users on notice of the terms you have distributed it under.

With 3D data, I have a hard time imagining the enforcement mechanism.

The only parallel I can think of is the patterns on currency that make it register with scanners and photocopiers and prevent being copied.

Yeah, pretty impossible to enforce, and you are appealing to peoples better nature, but I like the idea of a CC licence to show that if someone did rip you off, you’ve shown some due diligence to protect yourself from the bad party who might claim it was in the public domain. A bit of research on kickstarter and I found lots of comics that were sold both as printed books and PDF files, which is the closest analogy I could find.