Scenario: I'm cruising Thingiverse, and I find the awesomest thing. I NEED THIS IN MY LIFE. I download it, print it, and for whatever reason, it doesn't work quite right. OK, no big deal, I'll just download the source because the maker was so kind, modify it ever so slightly, and I will have the most awesomest thing evar!

Several hours later, I realized that I could have designed it from scratch in a software that is way more user friendly, deterministic, simpler, etc.

And then I do redesign it. From scratch. Maybe taking a measurement or two from the thing, or something related to the thing. And I refine it, and it turns out better than the original was.

Did I make a new thing? Did I only draw inspiration from the previous thing? Did I make a derivative work? Using Thingiverse's terminology, did I remix it?

I'm looking for some canonical guidelines to refer to for the US. Thingiverse can be an example, but god answers should not be limited to Thingiverse, nor my specific example.

I ran into this issue while trying to print out a case for a Raspberry Pi Zero. I'm not done redesigning it, but I've been wondering how I could share it on Thingiverse, and if any restrictions from the original model's licensing might affect me when I post my thing.

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    $\begingroup$ There are no "canonical guidelines" for this. Copyright law is incredibly complicated, with lots of gray areas. The description in your question is far too vague, and the answer could be anywhere between "yes, definitely copyright infringement" and, "no, totally in the clear". $\endgroup$ – Tom van der Zanden Jul 17 '18 at 8:22
  • $\begingroup$ So any random user has no hope of ever circumnavigating a possibly not at all copyright claim unless they talk to a lawyer? Seems kind of extreme given that this issue is bound to come up when 3D CAD starts to become more mainstream. $\endgroup$ – YetAnotherRandomUser Jul 17 '18 at 12:13
  • $\begingroup$ The issue isn't any more bound to come up with 3D CAD being mainstream than it is bound to come up with pencil and paper being mainstream. $\endgroup$ – Tom van der Zanden Jul 17 '18 at 12:39
  • $\begingroup$ It would be good to make your question more specific. Right now it essentially requires a book to be written on copyright issues. You have to consider in what ways your redesigned "thing" is similar or takes inspiration from the original "thing". $\endgroup$ – Tom van der Zanden Jul 17 '18 at 12:42
  • $\begingroup$ It's interesting that you feel guilty enough to ask. :D You'll need to make a personal ethical decision on whether sharing is more important than withholding as a rule for everybody. $\endgroup$ – OyaMist Jul 17 '18 at 14:51

I should start by saying that I am not a lawyer. I have been both the complainant and defendant in patent cases, and have had the role of observing copyright compliance for a performing arts organization. With that in mind, the following is my own opinion and information.

Ultimately, there is no simple answer to your question. It would depend on the case law that applies to 3D printed objects, which is not very clear. You are venturing into Copyright law, which is very different than Patent law.

For example, if someone had a patent on "A Raspberry PI case with a <describe a novel, special, functional feature>", and you made a case with that feature, you would be in infringement. It wouldn't matter if the case looked like the original, or was completely different. If it included that patented invention, you would be more likely to lose if challenged in court. The one thing about patent court prosecutions is that it is really rare that anyone actually "wins". The cost to put forward a case is very high, and usually someone runs out of money (sometimes even the "good guy") before a decision is reached.

Copyright is much harder and softer at the same time. Copyright can relate to the design feel of an object -- such as rounded vs. square, or using a trash can vs recycle bin icon. Prosecuting a copyright violation of this kind would require that the aggrieved rights holder demonstrate that the design was copied, or at least derived in an unpermitted way, from the original work. This is often more a matter of opinion than law, which is why the lawyers matter, as well as the judge and potential jury.

Technically, you are not free to do whatever you wish in the privacy of your own home. You are much less like to be detected and then prosecuted, and the penalties would be lower, but you are just as much in violation if you make one for your own use or sell them by the millions.

The best way to handle it, if you are prepared for possible adverse reaction from the original designer, is to ask them for permission. You can say ask for clearance to use, such as by saying:

I loved your object <thing> on Thingiverse. I plan to <put in your plans here -- make a few for me and my friends -- sell further varieties online -- whatever>. Although I didn't copy your design, I would like to acknowledge that I saw your design before doing my own. How shall I do that?

Your next steps will depend on how they respond. Most likely, they will either give you free leave to do as you wish, or they will ask for something.

This happens a great deal in music, and expensive and acromonious problems have developed over who actually composed a particular guitar riff. You can pick up the "Stairway to Heaven" case here. If you are doing this commercially, it is better to negotiate ahead of time. If you are putting your object back on Thingiverse for sharing, I'd just identify it as derivative an get on with life.


When you remix, either by modifying the existing CAD files (STL or sCAD or whatever), or by rebuilding essentially the same item from scratch, that is a remix and subject to whatever restrictions the original author put on his work.

So the critical issue so far as copyright is concerned is whether the output is a clear copy or remix. No different from taking someone's novel and rewriting it using Notepad++ and LaTeX instead of the original Microsoft World.

Now, when remix or reuse is allowed by the originator, it is still incumbent upon you to provide proper attribution, just as you would provide footnotes and bibliography so as to avoid plagiarism in a research paper.

All that said, you are free to do whatever you wish in "the privacy of your own home" (IANAL and laws vary by location, but the chance that the copyright holder will track you down because you have a widget in your bedroom are nil). You can't publish or sell, of course w/o permission.

  • $\begingroup$ The first paragraph presumes that the work that the derivative is made from is protected under copyright to begin with, which might not be the case for the object given as example in the question ("raspberry pi case") and that the copyrightable aspects of the object are preserved by the remix. If the design is "purely functional" it does not qualify for copyright protection. $\endgroup$ – Tom van der Zanden Jul 17 '18 at 16:59
  • $\begingroup$ Why is the question of clear copy or remix "the critical issue"? $\endgroup$ – Tom van der Zanden Jul 17 '18 at 17:00
  • $\begingroup$ Regarding the last paragraph: under United States copyright law, merely preparing a derivative work is illegal, even if you don't sell or publish it. $\endgroup$ – Tom van der Zanden Jul 17 '18 at 17:06
  • $\begingroup$ @TomvanderZanden and as I wrote , the chances of being caught, let alone prosecuted, are less than that of winning Powerball. $\endgroup$ – Carl Witthoft Jul 17 '18 at 17:45
  • $\begingroup$ I did read that, but you also wrote "IANAL and laws vary by location", and that kind of implies you're making some kind of legal claim. Right now it reads as "It isn't illegal and even if it were, they couldn't catch you anyway". $\endgroup$ – Tom van der Zanden Jul 17 '18 at 17:47

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