<p>You can use <a href="http://www.openscad.org/">OpenSCAD</a>. It's a script based powerful CAD open source software under GPL. 
On Thingiverse, a <a href="http://www.thingiverse.com/search/prolific/things?q=&amp;search_mode=advanced&amp;description=&amp;username=&amp;tags=Customizer&amp;license=">lot of things are</a> made with this CAD software (the <code>Customizer</code> flagged ones) and you can just download their source code (<code>.scad</code>) and directly edit them !</p>

<p>You can also import existing STL and edit them like they were a primitive shape like a cube. You can then interact with them by doing binary operations, adding parts, etc. </p>

<p>It is hard to start with if you have never coded, but that's worth it :</p>

<blockquote>
  <p>OpenSCAD is a software for creating solid 3D CAD models. It is free software and available for Linux/UNIX, Windows and Mac OS X. Unlike most free software for creating 3D models (such as Blender) it does not focus on the artistic aspects of 3D modelling but instead on the CAD aspects. Thus it might be the application you are looking for when you are planning to create 3D models of machine parts but pretty sure is not what you are looking for when you are more interested in creating computer-animated movies.</p>
</blockquote>

CC BY-SA 3.0
2016-02-17T08:46:33.147Z
Good point mentioning OpenSCAD! When downloading from Thingiverse editing the .scad files directly is nice solution - if you know how to use it.
Tormod Haugene
CC BY-SA 3.0
2016-02-17T18:23:58.500Z
OpenSCAD isn't a bad solution - however tweaking parts is a bit challenging as there isn't a way, AFAIK to measure an existing object to offset and tweak accordingly.
Jim
CC BY-SA 3.0
2016-02-19T21:31:16.563Z
If you have programming background, OpenSCAD is easy (but read up on the unusual scope rules); but if the original author was drawing in a GUI instead of coding, it may be hard to get any useful (human-readable) code out of their models and into OpenSCAD. Models of people, terrains, etc. are likely to be done with a GUI like Blender; engineered parts are likely to be done with OpenSCAD.
TextGeek
CC BY-SA 3.0
2016-02-16T17:57:57.167Z
2016-02-16T17:57:57.167Z
tourdetour
<p>There is no argument that the most successful FOSS 3D editor is Blender. It can both import and export STL files and export to STL or many other formats (DAE, OBJ, 3DS, FBX, DXF, WRL) so you can both use it to edit STL models as well as just use it as a STL converter.
<a href="https://www.blender.org/" rel="nofollow">https://www.blender.org/</a></p>

CC BY-SA 3.0
2016-02-05T09:38:48.933Z
Hi @Leo. I have downvoted your question, and here is why: stating that "There is no argument that..." strongly indicates that you cover up your own personal opinion as a fact - something that is frowned upon in the SE community. I suggest you either back up this statement, or find a somewhat more humble reformulation.
Tormod Haugene
CC BY-SA 3.0
2016-02-05T10:53:16.383Z
I don't care if it strongly indicates that it is my own personal opinion *in your opinion*. Statistically Blender is successful in all areas, which are feature completeness, stability, siz eof community (help), popularity (download count, number of users), development phase. These are statistics/facts. Whether my own opinion is also involved or not is even irrelevant at this point. So if you're going to downvote an answer which might be the best option for the person asking the question (the whole purpose of Q&A) for the sake of the "spirit of SE" then go ahead. I simply find that illogical.
Leo Ervin
CC BY-SA 3.0
2016-02-05T11:21:01.077Z
please understand me correctly: I am not saying Blender isn't a great software, and perhaps the best alternative in this case. However, *there is no argument* that there are other 3D editors that can edit STL files as well (see what I did there?). In other words, I'm not disagreeing with you, but simply asking if you would consider rephrasing it. Whether you do or not is entirely up to you, but I believe your answer will be *better* if worded differently.
Tormod Haugene
CC BY-SA 3.0
2016-02-05T18:33:34.437Z
Blender is successful - and I'm not debating that.  My question wasn't meant to instill a pissing match.  That said - Blender is really more oriented at animation; and editing models for 3D printing is kind of a "hack", being that it is geometry is "unit-less". Hence one can model proportionally, but then you have to scale to the real world outside of Blender.
Jim
CC BY-SA 3.0
2016-02-05T21:22:44.510Z
Tormod, please understand that I'm not talking like this because of my emotions, nor am I a fan of the software Blender, I'm just stating what I believe to be a fact. I see no reason to reword what I said simply because I believe what I said to be true. I don't think this is the situation where one needs to not seem biased or sound humble. As I mentioned, there are facts to back up what I said. Please understand that what you said about what SE community likes is also simply your opinion which I can disagree with. No pissing match here.
Leo Ervin
CC BY-SA 3.0
2016-02-05T21:28:10.687Z
Jim, Blender is a 3d modeller which has taken a generalist approach like many other 3d modellers, meaning that it can do many things, it is not design specifically for one task. I can tell you with 100% certainty that Blender is not more oriented at animation making. Like I said, it's a general 3d modeller.  And geometry is not unitless, you can choose Metric or Imperial mode in this menu: http://i.imgur.com/D1mdhDy.png  By default it is "none" or "Blender Units" which is more useful for other things when you're better off thinking in relative dimensions rather than real world units.
Leo Ervin
CC BY-SA 3.0
2016-02-05T21:30:22.570Z
Continued: there is also an addon for people who use it for 3d printing which is included with Blender now. http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Modeling/PrintToolbox  Not that it is necessary, but there's even that.
Leo Ervin
CC BY-SA 3.0
2016-02-06T07:39:29.090Z
@LeoErvin just edited your answer to help maintain integrity to the "political correctness" of your response.
tbm0115
CC BY-SA 3.0
2016-02-06T08:56:55.070Z
Sorry I could not approve that as in the link there was no statistical data, just mention that it has 3d printing tools built-in...
Leo Ervin
CC BY-SA 3.0
2016-02-06T10:49:21.900Z
@LeoErvin, I'm sorry for my own negative response to your question. For some reason, the formulation provoked me, which it probably shouldn't have.
Tormod Haugene
CC BY-SA 3.0
2016-02-06T10:55:54.513Z
@Tormod Haugene. No problem, I believe political correctness is overused these days, for a Q&A site I just don't see a place for it, as I think it will both make the questions and the answers longer and therefore less readable, that's why I write like this.  Now if you asked me to mention some sources to my claims that would be reasonable to me.
Leo Ervin
CC BY-SA 3.0
2016-02-06T11:09:47.453Z
@LeoErvin, I guess I'm more of the scientific writer type where you never make a claim without backing it up without at least 5 references. :-)
Tormod Haugene
CC BY-SA 3.0
2016-02-06T11:42:12.763Z
As someone who's in the 3d field I know almost everyone here knows what the major 3d modellers are capable of (Max, Maya, Blender, C4D, etc.) but we don't keep bookmarks to the things which led us to learn that. I'll try to dig up the facts.
Leo Ervin
CC BY-SA 3.0
2016-02-06T16:44:33.143Z
@LeoErvin The link that I tried to add to your response was a SE link, which is preferred over another website link. Did you have a look at the link in the posted question? It leads to an article providing sound statistical evidence that Blender is most used in the 3D printing community.
tbm0115
CC BY-SA 3.0
2016-02-06T16:57:00.247Z
Only a link that Blender has some tools for 3d printer users. Not a link that Blender is the most successful FOSS 3d editor which was what some people didn't like (FOSS means "free and open source", not about 3d printing).
Leo Ervin
CC BY-SA 3.0
2016-02-03T00:10:17.497Z
2016-02-06T08:55:53.777Z
2016-02-06T08:55:53.777Z
Leo Ervin
<p>If you want to do basic edits to an STL, a program such as <a href="http://www.meshmixer.com/" rel="noreferrer">MeshMixer</a> might be right for your. It offers the ability to combine and subtract models, add custom supports, and similar, in a fairly straight forward manner.</p>

<p>An alternative that allows your to do complex editing of STLs would be <a href="http://www.autodesk.com/products/fusion-360/overview" rel="noreferrer">Autodesk Fusion 360</a>. Here you can import STLs into meshes, which you then may convert into solids for further editing. It is more work to use, but a very flexible solution; you can i.e choose to only convert certain faces to solid, or use the mesh as a reference point for other designs. </p>

<p>As far as I know, neither of these are FOSS (free and open source),  but both are free for non-commercial use.</p>

CC BY-SA 3.0
2016-02-17T17:58:13.097Z
+1 for Meshmixer, love doing small fixes with it. It can't rescue everything, but it is certainly unique in its approach to modifying files (much more akin to literal sculpting than anything else I've used). Fusion360 often has issues with complex STL files (since it doesn't natively work in the STL format, so files have to be converted to the Fusion 'language').
Dustin Wheeler
CC BY-SA 3.0
2016-02-03T06:36:58.977Z
2016-02-03T07:04:37.060Z
2016-02-03T07:04:37.060Z
Tormod Haugene
<p>I have used Wings 3D (<a href="http://www.wings3d.com" rel="nofollow">http://www.wings3d.com</a>) for just that purpose. It is very easy to use, and has many other useful functions built in. Not only can you reform the mesh, but you also you have the ability to import and export many other meshes such as .obj, and etc. When you have completed your modifications you can export them in one of several formats (I find it easier to just keep it in .stl) and then use netfab (also has a free version with some limitations as compared to the paid version) to fine tune the mesh if it is not printable in its current format. Wings will export your modifications in .stl format, but you may have to fine tune to get rid of holes blemishes and etc., and you can view your changes in several views such as Gaussian and other forms. </p>

<p>If you decide to try Wings 3D you need to go through the tutorials, since there is a multitude of possibilities, including making your own meshes, beginning with several basic forms such as squares, cubes, cylinders and several other basic geometrical figures.</p>

<p>Using these two programs I have been able to modify many meshes and arrive at a very printable object. One of the features of Wings which has been quite valuable is the smoothing app which reduces the sharp division lines on some models.</p>

<p>Since both programs are free you can try them and uninstall them if they do not fill your needs. Blender is also an excellent free program, but I find Wings to be much simpler to use.</p>

<p>Hope this helps   </p>

CC BY-SA 3.0
2016-02-19T16:55:04.253Z
Wow, this is actually pretty well maintained surprisingly.  I will need to try this out.  As a software dev myself, I'm intrigued just because it's written in Erlang.  For those looking for the site: http://www.wings3d.com
Jim
CC BY-SA 3.0
2016-02-18T12:45:12.500Z
2016-02-19T19:05:05.370Z
2016-02-19T19:05:05.370Z
BYE
<p>If you want a WYSIWYG-style editor and are not content with OpenSCAD, I found 123D Design (Autodesk, definitively not FOSS but free for hobbyists) to have (on a Mac) a compromise between power and ease of use that most appealed to me.</p>

<p>If you insist on FOSS probably Blender comes closest, but I found it to be too idiosyncratic in interface and tools to be usable. </p>

CC BY-SA 3.0
2016-02-19T20:55:33.527Z
2016-02-19T20:55:33.527Z
ahulpke
<p>I'd like to customize and modify some parts on Thingiverse, beyond just simple scaling for 3D printing.</p>

<p>I've been looking for some tools that convert the STL files into something that is easily edited, but so far all that I've found are really buggy and crash frequently as soon as one loads a reasonably complex model.</p>

<p>Are there any free open source software tools that people can recommend that handle STL importing and editing? If not FOSS, what about just "free or nearly free for hobbyists, ed, non-commercial?</p>

CC BY-SA 3.0
2016-02-02T21:08:40.050Z
They exist; Blender for one. An exhaustive list is off topic here.
kaine
CC BY-SA 3.0
2016-02-04T15:58:43.277Z
Please note that STL, as a file type, is not designed to be edited and is susceptible to corruption if brought between multiple CAD programs. For this reason, it is often difficult to convert an STL back into a file type that is "CAD friendly". It's like crumpling a piece of paper or opening a JPEG a million times.
tbm0115
CC BY-SA 3.0
2016-02-06T01:04:17.017Z
I'm not sure about that. Sounds more like there being different revisions of the format and/or some 3d editors not creating the files properly which other 3d editors with more strict parsing will not load, than a limitation of a format. Personally I've created as well as edited STL files in Blender and used them in Repetier Host and I've never had an issue loading a file in both.
Leo Ervin
CC BY-SA 3.0
2016-02-06T07:31:53.320Z
@LeoErvin I was trying to convey the issues of 3D editors not importing/exporting properly as you said. Look into the following Wikipedia page as one of my sources https://en.wikipedia.org/wiki/STL_(file_format) . For a program like Blender, which can heavily rely on proper orientation of the triangulated solid, it is understandable that you haven't encountered an issue. However, there are other (not as well developed) applications that may choose to ignore or not use certain parameters within the file as they are not within scope of the application. So, just be careful which software you use.
tbm0115
<software><open-source><3d-models>
What are some good FOSS or free tools for editing STL files for 3D Printing?
Jim
# What are some good FOSS or free tools for editing STL files for 3D Printing?

(Asked by: username_0 on 2016-02-02)

I'd like to customize and modify some parts on Thingiverse, beyond just simple scaling for 3D printing.

I've been looking for some tools that convert the STL files into something that is easily edited, but so far all that I've found are really buggy and crash frequently as soon as one loads a reasonably complex model.

Are there any free open source software tools that people can recommend that handle STL importing and editing? If not FOSS, what about just "free or nearly free for hobbyists, ed, non-commercial?

**Tags:** software, open-source, 3d-models
> **Comments:**
> **username_1**: They exist; Blender for one. An exhaustive list is off topic here.  
> **username_2**: Please note that STL, as a file type, is not designed to be edited and is susceptible to corruption if brought between multiple CAD programs. For this reason, it is often difficult to convert an STL back into a file type that is "CAD friendly". It's like crumpling a piece of paper or opening a JPEG a million times.  
> **username_3**: I'm not sure about that. Sounds more like there being different revisions of the format and/or some 3d editors not creating the files properly which other 3d editors with more strict parsing will not load, than a limitation of a format. Personally I've created as well as edited STL files in Blender and used them in Repetier Host and I've never had an issue loading a file in both.  
> **username_2**: @LeoErvin I was trying to convey the issues of 3D editors not importing/exporting properly as you said. Look into the following Wikipedia page as one of my sources https://en.wikipedia.org/wiki/STL_(file_format) . For a program like Blender, which can heavily rely on proper orientation of the triangulated solid, it is understandable that you haven't encountered an issue. However, there are other (not as well developed) applications that may choose to ignore or not use certain parameters within the file as they are not within scope of the application. So, just be careful which software you use.  

---

## 5 answers

### Answer by username_4 on 2016-02-16. Score: 9

You can use [OpenSCAD](http://www.openscad.org/). It's a script based powerful CAD open source software under GPL.
On Thingiverse, a [lot of things are](http://www.thingiverse.com/search/prolific/things?q=&search_mode=advanced&description=&username=&tags=Customizer&license=) made with this CAD software (the `Customizer` flagged ones) and you can just download their source code (`.scad`) and directly edit them !

You can also import existing STL and edit them like they were a primitive shape like a cube. You can then interact with them by doing binary operations, adding parts, etc.

It is hard to start with if you have never coded, but that's worth it :

> OpenSCAD is a software for creating solid 3D CAD models. It is free software and available for Linux/UNIX, Windows and Mac OS X. Unlike most free software for creating 3D models (such as Blender) it does not focus on the artistic aspects of 3D modelling but instead on the CAD aspects. Thus it might be the application you are looking for when you are planning to create 3D models of machine parts but pretty sure is not what you are looking for when you are more interested in creating computer-animated movies.

> **Comments:**
> **username_5**: Good point mentioning OpenSCAD! When downloading from Thingiverse editing the .scad files directly is nice solution - if you know how to use it.  
> **username_0**: OpenSCAD isn't a bad solution - however tweaking parts is a bit challenging as there isn't a way, AFAIK to measure an existing object to offset and tweak accordingly.  
> **username_6**: If you have programming background, OpenSCAD is easy (but read up on the unusual scope rules); but if the original author was drawing in a GUI instead of coding, it may be hard to get any useful (human-readable) code out of their models and into OpenSCAD. Models of people, terrains, etc. are likely to be done with a GUI like Blender; engineered parts are likely to be done with OpenSCAD.  

---

### Answer by username_5 on 2016-02-03. Score: 6

If you want to do basic edits to an STL, a program such as [MeshMixer](http://www.meshmixer.com/) might be right for your. It offers the ability to combine and subtract models, add custom supports, and similar, in a fairly straight forward manner.

An alternative that allows your to do complex editing of STLs would be [Autodesk Fusion 360](http://www.autodesk.com/products/fusion-360/overview). Here you can import STLs into meshes, which you then may convert into solids for further editing. It is more work to use, but a very flexible solution; you can i.e choose to only convert certain faces to solid, or use the mesh as a reference point for other designs.

As far as I know, neither of these are FOSS (free and open source), but both are free for non-commercial use.

> **Comments:**
> **username_7**: +1 for Meshmixer, love doing small fixes with it. It can't rescue everything, but it is certainly unique in its approach to modifying files (much more akin to literal sculpting than anything else I've used). Fusion360 often has issues with complex STL files (since it doesn't natively work in the STL format, so files have to be converted to the Fusion 'language').  

---

### Answer by username_3 on 2016-02-03. Score: 4

There is no argument that the most successful FOSS 3D editor is Blender. It can both import and export STL files and export to STL or many other formats (DAE, OBJ, 3DS, FBX, DXF, WRL) so you can both use it to edit STL models as well as just use it as a STL converter.
<https://www.blender.org/>

> **Comments:**
> **username_5**: Hi @Leo. I have downvoted your question, and here is why: stating that "There is no argument that..." strongly indicates that you cover up your own personal opinion as a fact - something that is frowned upon in the SE community. I suggest you either back up this statement, or find a somewhat more humble reformulation.  
> **username_3**: I don't care if it strongly indicates that it is my own personal opinion *in your opinion*. Statistically Blender is successful in all areas, which are feature completeness, stability, siz eof community (help), popularity (download count, number of users), development phase. These are statistics/facts. Whether my own opinion is also involved or not is even irrelevant at this point. So if you're going to downvote an answer which might be the best option for the person asking the question (the whole purpose of Q&A) for the sake of the "spirit of SE" then go ahead. I simply find that illogical.  
> **username_5**: please understand me correctly: I am not saying Blender isn't a great software, and perhaps the best alternative in this case. However, *there is no argument* that there are other 3D editors that can edit STL files as well (see what I did there?). In other words, I'm not disagreeing with you, but simply asking if you would consider rephrasing it. Whether you do or not is entirely up to you, but I believe your answer will be *better* if worded differently.  
> **username_0**: Blender is successful - and I'm not debating that.  My question wasn't meant to instill a pissing match.  That said - Blender is really more oriented at animation; and editing models for 3D printing is kind of a "hack", being that it is geometry is "unit-less". Hence one can model proportionally, but then you have to scale to the real world outside of Blender.  
> **username_3**: Tormod, please understand that I'm not talking like this because of my emotions, nor am I a fan of the software Blender, I'm just stating what I believe to be a fact. I see no reason to reword what I said simply because I believe what I said to be true. I don't think this is the situation where one needs to not seem biased or sound humble. As I mentioned, there are facts to back up what I said. Please understand that what you said about what SE community likes is also simply your opinion which I can disagree with. No pissing match here.  
> **username_3**: Jim, Blender is a 3d modeller which has taken a generalist approach like many other 3d modellers, meaning that it can do many things, it is not design specifically for one task. I can tell you with 100% certainty that Blender is not more oriented at animation making. Like I said, it's a general 3d modeller.  And geometry is not unitless, you can choose Metric or Imperial mode in this menu: http://i.imgur.com/D1mdhDy.png  By default it is "none" or "Blender Units" which is more useful for other things when you're better off thinking in relative dimensions rather than real world units.  
> **username_3**: Continued: there is also an addon for people who use it for 3d printing which is included with Blender now. http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Modeling/PrintToolbox  Not that it is necessary, but there's even that.  
> **username_2**: @LeoErvin just edited your answer to help maintain integrity to the "political correctness" of your response.  
> **username_3**: Sorry I could not approve that as in the link there was no statistical data, just mention that it has 3d printing tools built-in...  
> **username_5**: @LeoErvin, I'm sorry for my own negative response to your question. For some reason, the formulation provoked me, which it probably shouldn't have.  
> **username_3**: @Tormod Haugene. No problem, I believe political correctness is overused these days, for a Q&A site I just don't see a place for it, as I think it will both make the questions and the answers longer and therefore less readable, that's why I write like this.  Now if you asked me to mention some sources to my claims that would be reasonable to me.  
> **username_5**: @LeoErvin, I guess I'm more of the scientific writer type where you never make a claim without backing it up without at least 5 references. :-)  
> **username_3**: As someone who's in the 3d field I know almost everyone here knows what the major 3d modellers are capable of (Max, Maya, Blender, C4D, etc.) but we don't keep bookmarks to the things which led us to learn that. I'll try to dig up the facts.  
> **username_2**: @LeoErvin The link that I tried to add to your response was a SE link, which is preferred over another website link. Did you have a look at the link in the posted question? It leads to an article providing sound statistical evidence that Blender is most used in the 3D printing community.  
> **username_3**: Only a link that Blender has some tools for 3d printer users. Not a link that Blender is the most successful FOSS 3d editor which was what some people didn't like (FOSS means "free and open source", not about 3d printing).  

---

### Answer by username_8 on 2016-02-18. Score: 2

I have used Wings 3D (<http://www.wings3d.com>) for just that purpose. It is very easy to use, and has many other useful functions built in. Not only can you reform the mesh, but you also you have the ability to import and export many other meshes such as .obj, and etc. When you have completed your modifications you can export them in one of several formats (I find it easier to just keep it in .stl) and then use netfab (also has a free version with some limitations as compared to the paid version) to fine tune the mesh if it is not printable in its current format. Wings will export your modifications in .stl format, but you may have to fine tune to get rid of holes blemishes and etc., and you can view your changes in several views such as Gaussian and other forms.

If you decide to try Wings 3D you need to go through the tutorials, since there is a multitude of possibilities, including making your own meshes, beginning with several basic forms such as squares, cubes, cylinders and several other basic geometrical figures.

Using these two programs I have been able to modify many meshes and arrive at a very printable object. One of the features of Wings which has been quite valuable is the smoothing app which reduces the sharp division lines on some models.

Since both programs are free you can try them and uninstall them if they do not fill your needs. Blender is also an excellent free program, but I find Wings to be much simpler to use.

Hope this helps

> **Comments:**
> **username_0**: Wow, this is actually pretty well maintained surprisingly.  I will need to try this out.  As a software dev myself, I'm intrigued just because it's written in Erlang.  For those looking for the site: http://www.wings3d.com  

---

### Answer by username_9 on 2016-02-19. Score: 0

If you want a WYSIWYG-style editor and are not content with OpenSCAD, I found 123D Design (Autodesk, definitively not FOSS but free for hobbyists) to have (on a Mac) a compromise between power and ease of use that most appealed to me.

If you insist on FOSS probably Blender comes closest, but I found it to be too idiosyncratic in interface and tools to be usable.


---

