## Want to hire independant contractor / FreeCAD user to make parametric model of a spiral

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John Walt Childers
Posts: 4
Joined: Sun Jan 14, 2018 5:55 am

### Want to hire independant contractor / FreeCAD user to make parametric model of a spiral

Attached is a pink colored 2D spiral on a blue background.
Single spiral.jpg (320.3 KiB) Viewed 480 times
Can you create a spiral like this in FreeCAD as a parametric model? I would want to be able to tweak it, not just make a duplicate. By tweaking, I mean vary the growth factor and thickness.
Please keep in mind that I’m a newbie with FreeCAD and parametric modeling. Thus, some of my ideas on mechanics might seem naive. Nonetheless, here is what I think about the mathematics:
I believe the Golden Spiral paradigm and equations will work for this. Two spirals would form the edges of the pinkish spiral using two slightly different growth factors, until finally the spiral thins in width as the outer spiral gets truncated by a boundary curve, possibly a circle.
Golden Spiral equations are at
https://en.wikipedia.org/wiki/Golden_spiral
Golden Spiral freecad web discussion is at

The second attachment is a double spiral, which is the ultimate goal. The single spiral depiction was made by using Gimp paintbrush to paint over one of the spirals in the image below. I want to get a single spiral that when copied and pasted at 180 degrees rotation would look like this second attachment.
Double Spiral.jpg (279.59 KiB) Viewed 480 times
The two spirals must not touch at any point. Once the two identical spirals were in place, it should be possible to tweak them both by modifying their parameters with identical adjustments. Or possibly this would be a script that could be edited to tweak parameters like the two growth factors and then re-run.
Anyone interested should contact me and we can discuss particulars, including pay.
Part of this endeavor would be to teach me how to use your script or macro.
Warm regards,
John Walt Childers
Warm regards,
John Walt Childers
microelly2
Posts: 4440
Joined: Tue Nov 12, 2013 4:06 pm
Contact:

### Re: Want to hire independant contractor / FreeCAD user to make parametric model of a spiral

welcome to the forum,
as you have a mathematical description of the curves it is possible to create a point set and interpolate it as a curve with expected tolerance
there is a macro to generate curves by an equation.
I think you will get help from the forum, you put the post i the job subforum, I hope someone will read it and help from here, otherwise we can move it to the "Help on using FreeCAD" category.
victor.cis
Posts: 10
Joined: Thu Apr 20, 2017 11:11 am

### Re: Want to hire independant contractor / FreeCAD user to make parametric model of a spiral

Hi John,

I would be glad to assist you.

PM sent

Regards,
Victor