<p>The best free solution I could find was to graph this (in Desmos), screenshot it, and convert it into a SVG, convert that into an OpenSCAD file, and then use that to make the STL. A similar process is shown on someone's blog <a href="https://johnchapin.com/2015/08/05/desmos-to-3d-printout-in-30-minutes/" rel="nofollow noreferrer">here</a>.</p>

CC BY-SA 3.0
2017-05-17T03:46:27.480Z
2017-05-17T03:46:27.480Z
werdna3232
<p>The Wolfram Alpha "Data Download" feature supports STL format, but is only enabled with a Pro Account.</p>

<p>When I click your link to Wolfram, I see the visualization of your equations at the bottom of the page; when I hover over the image, several buttons show below it. One of them is "Data", with a download icon. This gives a number of download options. The File Format drop down includes "STL".</p>

CC BY-SA 3.0
2017-05-16T16:19:24.600Z
I don't have my printing software with me, so I haven't verified that the STL file will be usable...
mbmcavoy
CC BY-SA 3.0
2017-05-16T21:27:57.073Z
Is there a way to get this without a pro account? (Or could you share the STL with me?)
werdna3232
CC BY-SA 3.0
2017-05-16T21:42:14.123Z
I don't have an account at all. I'm not signed in, I just clicked your link. I'll see if I can add screenshots to my answer.
mbmcavoy
CC BY-SA 3.0
2017-05-16T21:46:58.803Z
Ah - I see the actual download is disabled without having a Pro account. I will revise my answer.
mbmcavoy
CC BY-SA 3.0
2017-05-16T16:17:18.310Z
2017-05-16T21:51:18.270Z
2017-05-16T21:51:18.270Z
mbmcavoy
<p>I have a solid of revolution defined by two equations, and I want to generate a STL file for printing from the <a href="https://www.desmos.com/calculator/eh18uwasw9" rel="nofollow noreferrer">difference of the two equations</a>, revolved around x=0. I can get a good visualization when I <a href="https://www.wolframalpha.com/input/?i=rotate%20the%20region%20between%20x%3Dsqrt(129%2B12y-y%5E2)-15.858%20and%20x%3Dsqrt(129%2B12y-y%5E2)-16.358%20around%20x%3D0%20from%20y%3D0%20to%20y%3D4" rel="nofollow noreferrer">query this on Wolfram Alpha</a>, but I cannot figure out how to download an STL of this. I know there is a way to do this via Wolfram's Development Program but I'm not sure how or if that is the best way to do this. Solutions do not have to involve WA.</p>

CC BY-SA 3.0
2017-05-16T06:37:55.703Z
A programmatic CAD like OpenSCAD or implicitcad will do the job.
abruski
CC BY-SA 3.0
2017-05-16T13:24:04.737Z
Yes, [OpenSCAD](http://openscad.org) is free; you should give it a try.
Davo
CC BY-SA 3.0
2017-05-16T13:28:25.340Z
@Davo how can I enter equations into OpenSCAD
werdna3232
CC BY-SA 3.0
2017-05-16T13:34:16.707Z
Well, I'm not an OpenSCAD guy, but I've seen people work wonders with it. The download includes practice formulas and tutorials, if memory serves.
Davo
<3d-models>
How to generate a STL from a rotational solid of two equations?
werdna3232
# How to generate a STL from a rotational solid of two equations?

(Asked by: username_0 on 2017-05-16)

I have a solid of revolution defined by two equations, and I want to generate a STL file for printing from the [difference of the two equations](https://www.desmos.com/calculator/eh18uwasw9), revolved around x=0. I can get a good visualization when I [query this on Wolfram Alpha](https://www.wolframalpha.com/input/?i=rotate%20the%20region%20between%20x%3Dsqrt(129%2B12y-y%5E2)-15.858%20and%20x%3Dsqrt(129%2B12y-y%5E2)-16.358%20around%20x%3D0%20from%20y%3D0%20to%20y%3D4), but I cannot figure out how to download an STL of this. I know there is a way to do this via Wolfram's Development Program but I'm not sure how or if that is the best way to do this. Solutions do not have to involve WA.

**Tags:** 3d-models
> **Comments:**
> **username_1**: A programmatic CAD like OpenSCAD or implicitcad will do the job.  
> **username_2**: Yes, [OpenSCAD](http://openscad.org) is free; you should give it a try.  
> **username_0**: @Davo how can I enter equations into OpenSCAD  
> **username_2**: Well, I'm not an OpenSCAD guy, but I've seen people work wonders with it. The download includes practice formulas and tutorials, if memory serves.  

---

## 2 answers

### Answer by username_0 on 2017-05-17. Score: 0 | Accepted answer

The best free solution I could find was to graph this (in Desmos), screenshot it, and convert it into a SVG, convert that into an OpenSCAD file, and then use that to make the STL. A similar process is shown on someone's blog [here](https://johnchapin.com/2015/08/05/desmos-to-3d-printout-in-30-minutes/).


---

### Answer by username_3 on 2017-05-16. Score: 0

The Wolfram Alpha "Data Download" feature supports STL format, but is only enabled with a Pro Account.

When I click your link to Wolfram, I see the visualization of your equations at the bottom of the page; when I hover over the image, several buttons show below it. One of them is "Data", with a download icon. This gives a number of download options. The File Format drop down includes "STL".

> **Comments:**
> **username_3**: I don't have my printing software with me, so I haven't verified that the STL file will be usable...  
> **username_0**: Is there a way to get this without a pro account? (Or could you share the STL with me?)  
> **username_3**: I don't have an account at all. I'm not signed in, I just clicked your link. I'll see if I can add screenshots to my answer.  
> **username_3**: Ah - I see the actual download is disabled without having a Pro account. I will revise my answer.  

---

