Fibonacci Spiral

[Anonymous]

Ok,

I have a concept in mind where a rotating spiral would probably be the correct answer to a problem, however it would need to be a Fibonacci spiral.  I would like to laser cut one but not quite sure how to accurately create one in sketch mode.  My math sucks and I am sure there is some kind of formula that could be used so does anyone have a script or something similar that would create a pretty accurate spiral?  There is an App in the store that creates curves etc but not sure if it could do this or not.

Any suggestions anybody?

David

[HughesTooling]

Is that the same as a golden ratio spiral, if it is see this thread. It's hard to tell with a quick google search but I think they're different but the link might get you started

Mark

[Anonymous · Accepted solution]

Yes Mark,

A golden spiral can be created using the Fibonacci sequence progression.  The link you provided is good.  You must use tangent arcs to join to previous arcs with the radius of the next Fibonacci number in sequence.  I read somewhere that using this method is not a perfect spiral in that it is really just a concatenation of arcs but when I modeled a solid from the sketch I made and rotate it, it is close enough for me given that the diameter of the rod it is moving has a plus or minus 0.1mm tolerance anyway.

Thanks you for the post.  I will accept this as a solution.

David.