Pandora style of chain

Hi all and thank you for adding me to the group.

I need a little advice on how to model in Rhino a chain very similar to a Pandora bracelet chain, not the charms but just the chain its self.

Thank you

Hi Tim - welcome aboard - can you post an image?


Thank you Pascal. I didn’t know I could post an image!
I think that may be my second question :slight_smile:

(drag and drop as well as copy/paste also works)


Thank you

Pandora indeed.

Start with analysis of what it might be. Looks like a helix around curve with two profiles per turn.

For a straight piece you could simply run _Sweep2, picking the helix, and the central curve as rails, and whatever double profile would be:


But we need to bend it, so double profile doesn’t cut it. That means we need to split the profile, and add one more helix at the middle of the first one. That second helix must be shifted along the curve by 1/ 2 of the turn (if the turn distance is 10mm, then the second helix must be shifted by 5mm).

Look at red and green set of curves:

helix-around-curve.3dm (414.5 KB)

Both central curves are extended by 5mm at the end after adding the helices.

My mockup should give you just some idea. To build it perfectly you probably need much more that.

Thats fantastic 0netech, thank you so much. Your advice is similar to what I had in mind but I just couldn’t get it in the right order.

Again thank you for all your swift responses.


You are welcome. It was an interesting problem.

After a good night sleep I now can see where I’ve been quite sloppy. The central curves could’ve been better aligned with profiles, and you could temporarily pipe the central curves with the same radius as helix to extract an isocurve, and place profiles more precisely. So, I’ll leave it to you as an exercise ) Cheers!