Reengineering: licence, copyright, patent

I was hoping to make a very short post about this but that is beyond my skill.


I am building a LowRider2, which I bought from V1 Engineering’s shop, and I want to modify it. How might I modify existing parts or create new parts for it? How might I engineer, or reengineer, parts or objects generally?

This led me down several rabbit holes, long impassioned forum posts, YouTube videos etc. I believe I have found the answers to my questions. If you have different views, please comment but please support those comments with facts or references.

Reasoned debate is asked for: no one needs another flame war.

The Problem

I would like to reengineer an existing part. Can I do this? What restrictions are there?

In the UK (and elsewhere but not everywhere) you are permitted to do anything that you like unless there is a law that prevents this. If I want to copy a part, the laws that might prevent this are copyright and patent (and related intellectual property rights), in addition I might be granted a licence to do something otherwise not permitted.

Note a licence only works where something is restricted in the first place (copyright, patent) and that the licence grantor is the person or company that owns the restricted thing. I can grant you a licence to dig up my neighbour’s garden but that licence is meaningless.

It’s your responsibility to defend your intellectual property (IP) and to take action if someone’s used it without permission (known as ‘infringement’).
Examples of IP infringement include when someone:
uses, sells or imports your patented product or process
uses all or some of your work under copyright without your permission
makes, offers or sells your registered design for commercial gain
uses a trade mark that’s identical or similar to one you’ve registered “In particular, a license may be issued by authorities, to allow an activity that would otherwise be forbidden” “Copyright is a type of intellectual property that gives its owner the exclusive right to make copies of a creative work, usually for a limited time.” “A patent is a title that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of years in exchange for publishing an enabling public disclosure of the invention”

Legally Copying/Reengineering Things

First, decide what, if anything is owned by someone else:

  • Is there a valid copyright (copyright only extends to artistic works and, weirdly, software, databases and web sites)?
  • Is there a valid patent (generally only for inventions)?
  • Are there other protected intellectual property rights (e.g. trade-mark)?

If none of the above a true, then I can copy the thing. If there are restricted item(s), then I can still copy the thing provided that I remove the restricted items(s) from my version (e.g. by removing someone’s logo).

If any of the above is true, is there a licence that I can be granted ? If yes, then I can copy the thing.

Replacement Example

Imagine that I want to reengineer this: Ass Saver - Bicycle Mudguard by fgebhart - Thingiverse.

I believe that, both legally and practically, there is nothing to stop anyone taking the original “Ass Saver” and republishing it as their own. One could make the argument that the shape is stylised and looks like a feather - in that case you might need to make it look different.


What’s the deal with copyright
“In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work.”

As long as you’re not making 1 to 1 copies for sale, Ryan doen’t really care if you modify parts. We would ask that you keep the same license if you do post it to a sharing site.


You’re making the assumption that the stl isn’t copyrightable. And therefore you don’t have to listen to the license. This needs to be tested, but there are arguments that defend that copyright. You can’t copyright a shim. But the definitions of “functional” and “art” are legal terms and not common sense ones. “Art” can be copyrighted, and if you want to use the stl, you need to abide by the license.

That said, the license (and clarifying information from Ryan) have said pretty clearly: Please modify and share the parts. Please keep the same license on the modified parts. Please don’t sell copies of unmodified or barely modified parts you print.

I’m not a lawyer, but I don’t think it matters. Sites like ebay honor the trademark and copyright. If it ever needed to go to the point where we made a judge or jury decide, everyone would lose.

If you don’t like it, there are lots of other designs that are CC0. But I personally like it here. I like that we have a small store to support this community and it supports the designer and new versions. I like that I can make supporting parts, or modify the parts and share them. I like that even Ryan helps someone who prints the parts themselves and doesn’t give him a nickel. That ecosystem depends on being able to stop the ebay sellers who just want to print and ship. That’s the only real threat the copyright is trying to defend against.


Don’t overthink it. Don’t be a dick. Do give back to the ecosystem. Do be open and transparent with what you’re doing. Do keep asking questions and trying new things. Don’t take food out of the mouth of the one(s) who have put their blood, sweat, and tears into their work.

Mainly, don’t be a dick. In general, we assume you aren’t going to be one, although asking a lot of nit-picky questions about the raggedy edge of the law around the IP looks like red flags that you’re angling for a loophole to be a dick. And I have to stress that this is my opinion about what the questions appear to indicate. Not what your actual intentions are, or what you have, or are intending to do.

Or he just wants to make double sure not to step on toes?

FWIW, I don’t think anyone is in danger of being a dick (in this topic anyway).

But if you meant to say, be nice to each other, then I agree :slight_smile:

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Probably, I could just be paranoid grumpy between cup 1 and 2… :coffee:

If it adds to the project in some way, apply the same license as the part you are referencing. You are free to sell it if you want to and even license others to do so.

Now where I get bothered is when people have it in their mind they are going to make their own full and complete version for ANY reason. If that is the case, it should be of your own design and obviously so. There are thousands of design and engineering choices to be made on a machine like this, I have already made several very different versions myself and these days there are thousands of similarly functioning machines out there.

If you are just trying to get around a license please just stop and find another project that does not impose these restrictions.

Not sure why the legalities are brought up but if you want my non-legal opinion click below.


People redesign, and sell their own creations all the time based on my/our work. They do so with my/our support because it expands the capabilities in one way or another. Sometimes they just like the way their part looks more than mine. This is in the spirit of the project.

I prefer to share my work with people that want to make and use it for free.

If someone feels the right to sell exact or nearly exact copies of my work, or try to license exact or nearly exact copies differently, well I just do not agree.


Maybe both per Schrodinger?

I got rid of the original examples because they are emotive. Imagine that I want to reengineer this: Ass Saver - Bicycle Mudguard by fgebhart - Thingiverse

What restrictions are there, if any, against doing so?

My background is the software industry where copyright and licencing are a big deal. That is the model that I came here with. That model doesn’t work here. Patents are the correct model in this industry.

Given the above, and given what I originally wrote, what restrictions are there on reengineering?

No, I am not trying to be a dick - remember that I bought a kit from V1 Engineering and that I have no intention of reselling this design.

No, I am not trying to find a loophole. I am trying to work out how to reengineer parts. If I want, for my own purposes, to build my own part for anything, are they any legal restrictions in doing so (other than the ones identified above)? If I want to build a better bottle opener, how might I do that?

I am saying that you can’t copyright an STL. You can copyright the logo, however, and you can copyright the work of art that is represented by the STL but not the STL itself and not things which aren’t works for art. Thus you cannot protect it with a licence.

I think that this ecosystem actually depends on the fact that V1 Engineering packages and ships all of the parts conveniently and provides excellent support.

I would guess that previous ebay sellers failed because they provided sub-standard parts.

I think that taking a design and simply replacing the licence is a terrible idea. If you accept that something can be licenced, then you should adhere to the original licence terms.

If you don’t like GPLv3 then you need rewrite the entire software from scratch, without copying any source code.

What I am saying is, when I investigated the issue, I found that any licences based on simple copyright would be unenforceable.

Well, yes, I was trying to do that but I failed. I guess that I will just have to settle for exploring the issue and, hopefully, getting back reasoned arguments and actual references.

If it’s for your use (including perhaps shared among your friends), there’s no restrictions. If you want to release it to the public, it is requested that you do so for free, and giving whatever credit is due.


Did I answer your question? This adds the qualifier of “for your own purposes”, that and reengineer are vague questions.

As you can tell this is a touchy subject. If you look there are cases of both enforceable and not, seriously. I am not a lawyer and I have no place giving my uneducated opinion as anything other than that.

You say re-engineer, that term is what is causing the issue. If you make your own thing that is fine no one here will argue that. It is just every time this question comes up most feel like removing my logo or “making the part from “scratch”” constitutes re-engineering. Without specifics, you are just poking at a fine line we are on different sides of. Give some specifics of what re-engineering means to you and things should be much clearer.

If you want legalities, no one here to my knowledge is a lawyer. I have only asked of people what I feel is fair, and only enforced anything that has been within my legal rights for where I live and the companies that enforce them are headquartered. If you want to ask me permission, without getting lots of opinions, something you might want to contact me privately.


I also am not a lawyer, but as far as I understand things, other than general familiarity with different licensing models, @vicious1 is the only person who’s opinion really matters on this as he’s the creator/license grantor, as well as the sole person who has to take on the work of protecting his intellectual property. If you have specific questions it’s probably best to check with him one-on-one.

I appreciate that you’re asking, but by asking the whole forum you’re addressing the wrong authority. The rest of us tend to be a bit protective, because when these questions have come up in the past they have sometimes been followed by actions that were interpreted as being in bad faith.

I hope that your experience on the forums has been, and will continue to be positive. That’s the part the rest of us can play - maintaining a supportive community.


No, this is not a positive experience. I asked a set of questions expecting positive engagement. Instead I have been called names and everyone has assumed that I have the worst possible motives.

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