Morbius

aeden_moore

How do you model morbius?

SethF

Do you possibly mean a möbius strip?

john_mcclary

Here is one way I suppose. möbius | Part Studio 1 (onshape.com)

Parasolid won't allow the surfaces to join. So, the closest I could get the two edges was 0.000001" apart



If you try and make it a part with thickness, then the closest I could get was .0001" gap


If someone could create a "twist along path-Sweep" that would make this all easier. But for now, here is a manual way of doing it.
Should be enough for 3D printing I would assume the two ends would fuse naturally, or else some glue would finish the job.

The first two sketches and the projected curve were not necessary, I just wanted to play around a bit more with a fancier shape


Man, I love playing with Onshape sometimes..

steve_shubin

Here is a method using the 3D Spiral tool

The closest I could get is .000079

https://cad.onshape.com/documents/665bea71fed01d7fce44e077/w/e82583e298725196049ee171/e/ccfefab5d0512cd365ade246

john_mcclary

I tried to start with 3D spiral, but couldn't get half a rotation, and gave up.

What you did. . . Whoa... I didn't get what you were doing until I rolled it back to the beginning and stepped forward one at a time. Once the loft hit it finally clicked. Very cool

steve_shubin

@john_mcclary

Thanks John. I really appreciate that. Yeah my old brain seemed to work this one RARE time. LOL

Yeah that lead in line on the sketch was the exact length as the circumference of the circle (2*Pi*4)     So I had ‘HALF A REVOLVE’ of the spirals before they ever hit the circle. And the other half revolve happening within the circle

It would really be nice if the 3D Spiral tool would allow for other than whole number revolutions. It would’ve saved a lot of steps

Another thing — I realized I didn’t need two booleans so I eliminated one of those. There is now just one boolean in the feature list

One thing that had me bewildered, was trying to figure out if there was a way to split the curved 3D lines (the spirals). But there seems to be no way to break or cut a spiraled line, or at least, there’s no way I  could come up with. So I had to do the extrusions and split the surfaces, and then use the edges of those surfaces for the loft. But if somebody knows a way to break or cut 3D lines, I’d really appreciate the info on how to do it

I likely could’ve used one extrusion for both spirals, instead of two. But I wanted to extrude each spiral AWAY from the top plane or away from each other, so I used 2 extrusions.

But when it all comes down to brass tacks John, you still got it quite a bit closer together   —   .000001

How you did that is mind boggling !

john_mcclary

steve_shubin said:

But when it all comes down to brass tacks John, you still got it quite a bit closer together   —   .000001

How you did that is mind boggling !

guess and check my friend