# [OpenSCAD] Help Request... Channel for a LED strip

Tue Nov 19 07:17:12 EST 2019

The equation for a helix is  [r * sin(a), -r * cos(a), pitch * a / 360] where
a goes through 360 for each turn.

Not sure what you mean by the angle exactly because it is on a curve and it
is more usual to specify pitch. If it was unwound I think the angle would
be atan(pitch / 2 * PI * r).

On Mon, 18 Nov 2019 at 18:31, Hugo Jackson <hugo at apres.net> wrote:

> I've encountered a design problem that is beyond my limited geometry
> skills so I thought I would email the group in case there's someone who
> could give me some information as to how I might go about solving the
> problem.
> I'm working with a typical LED strip which I want to provide a spiral
> channel for. That in itself is straightforward but leaves a vertical
> channel that has all the LED's facing inward. So I imagine that by angling
> the channel I can get the LED's to face more forward. To my intuition this
> would have the result that the channel would have a natural pitch or space
> between vertical channel layers so that the non-flexible width of the strip
> is not compromised and the amount of that pitch and perhaps even the radius
> of the spiral at any given point could be computed by the angle of the
> channel.
> So unless I'm mistaken about the trajectory of an angled channel in a
> spiral, can anyone supply me with the equation for plotting the path of a
> helical spiral according to the angle of the strip?
> _______________________________________________