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Spiral with not-stretched cross-section?

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Spiral with not-stretched cross-section?

benjaminhill
When you make a spiral, the shape that is extruded is facing upwards, so it kinda gets "smeared" depending on how many twists you do.

<code>
linear_extrude(height = 10, center = true, convexity = 10, twist = 360*2)
translate([2, 0, 0])
circle(r = 1);
</code>

Is there a way to make this more of a "spring" shape with a cross-section that is perpendicular to the twisted extrusion?  Like if I wanted a wire with a star-shaped cross section wound in a spiral, doing it with the above way would make a very smeared star, especially if I had twist=360*5.

I think it would involve rotating and scaling the cross section shape in a way that counteracts the angle of the linear_extrude twist value, based on the height and translation.  But I'm not sure...
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Re: Spiral with not-stretched cross-section?

Caddiy
You can get a square cross section spring by stacking spirals:

for(z = [-0.35 : 0.05: 0.35])
translate([0,0,z])
linear_extrude(height=10*sin($t*360)+14, twist=360*5)
translate([10.5,0])
scale([1,0.5])
circle(0.5);

Maybe a star is possible with some extra tricky manipulations.
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Re: Spiral with not-stretched cross-section?

Caddiy
Something like this?

https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/2D_to_3D_Extrusion#Twist

(Scroll down to -500° of Twist)