I need a helix curve

I need to parametrically generate a helix in Grasshopper that provides all the variables as the Rhino helix. I searched here and in the Rhino forums and it seems there is no component like that. I'm still a bit of a beginner so I'm uncertain how to proceed.

Any thoughts?

Thanks in advance,

Robb

Replies to This Discussion

Permalink Reply by mark zirinsky on September 25, 2017 at 9:05pm

Permalink Reply by David Rutten on September 26, 2017 at 4:42am

The problem with this approach is that the ends of the curves have incorrect tangents. Additional care needs to be taken to make sure the tangents are correct, or, alternatively, the spiral needs to be created larger than required and then cut down to size.

@Robb, all the variables of the _Helix command? Pitch and Turns are mutually exclusive (or rather, they are different ways to describe the same thing) and as such you cannot specify them both.

Also the start angle and radius are specified by picking a single point, do you want to provide a point, or separate numbers to control angle+radius?

Permalink Reply by David Rutten on September 26, 2017 at 4:56am

Here's an approach for arbitrary base curves. I've taken no measures to 'fix' the tangent at the start and end yet though.

Attachments:

spiral.gh, 22 KB

Permalink Reply by Robb McDougle on September 26, 2017 at 5:43am

I did play with that one above some and it helped. My problem is rather simple i.e. Source curve -> Helix with turns per unit of source length and radius. I noticed the end tangent issue and have no problem trimming some excess.

I'll play with what you posted below and see how that suits the problem. Looks good from the image.

Many thanks for all input

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