How can I rotate a ribbon 180 degrees instead of 360?

Hi, I worked with this:


mob.gh (14.1 KB)

I would like to keep the whole algorithm, but just turn the ribbon 180 degrees instead of 360. So it basically should be a mobius strip in the end. Reading articles about how to create mobius strips didn’t help me with my specific script.

Could someone help me please?

There are many threads on this forum about Möbius strips:

This definitely isn’t as easy as one might think, eh?

I struggled for awhile to come up with this:


moebius_2023Feb1a.gh (26.3 KB)

It works better with more divisions than less - see ‘Frames’ slider in blue group:

As an after thought, I copied your code (white group) that thickens the result using offset surface but that fails for obvious reasons:


moebius_2023Feb1b.gh (29.7 KB)

So I tried lofting rectangles instead of lines. It works for 180 degrees but fails for 360. :frowning:


moebius_2023Feb1c.gh (18.4 KB)

@Joseph_Oster
I see I’m not the only one that was surprised by how tedious this is !
The Loft doesn’t work for an even amount of turns. Even though the first and last section are different lines and the Closed option is disabled, the Loft fails :man_facepalming:

I got it to work by toggling the closed option depending on the presence of duplicates.

mob.gh (18.4 KB)

2 Likes

Very nice. Yeah, it wore me down. Not easy!

moebius_2023Feb1c 2.gh (26.6 KB)

Skipping even numbered half-rotations is cheating @maje90. :wink: @magicteddy wins the prize on this one, he did some very nice work. :trophy: I would do a few small things differently but there’s no faulting success.

3 Likes

This abomination that I missed, for starters !

image

I’m not sure what that means but yep, that’s one of them. There are more but again, I won’t quibble. Your model is way better than mine. :sunglasses:

Thanks @Joseph_Oster @maje90 @magicteddy

Am I blind or is this still no usual mobius strip?

I guess the ribbon should be rotated 180 instead of 360 degrees at the cutting edge, like this:

There is a ‘Nb Turns’ slider, adjust it to1. (purple group, top left)

Ahh, I see. So unequal numbers generate usual mobius strips and equal numbers a 360 degrees rotation?

Nb Turns’ X Pi (180 degrees)

1 Like

Thanks