# How can I create a Mobius ring?

I want to create a Mobius ring. I managed to do it by twisting (rotating using proportional editing) then using a curve modifier. But the faces were full of creases no matter how I smoothed them.

I then tried to extrude a plane converted to a curve which was getting there. But I cannot see a way to join two edges of the Mobius ring with a surface. I would appreciate any pointers.

Stephen

• Might be helpful to add a picture of a mobius ring for those that don't know what it is. – Ray Mairlot Aug 8 '14 at 9:58
• That's a good idea. I can show an animation. My problem occurs when I changed the shape from a cuboid to a cut away shape. – Stephen Aug 13 '14 at 21:41
• Typical. I forgot to post yhe link. youtu.be/wsebFCno16Y – Stephen Aug 13 '14 at 21:47

The easiest way (I think) to create a Mobius ring is to use a bezier curve with an extrude value.

2. Extrude and move the curve points into a rough circle.

3. Increase the 'Extrude' value on the curve properties to give the curve thickness:

4. The trick is to pick one of the middle curve points and press Ctrl+T to start the 'Tilt' tool. This will allow you to rotate the curve point. Type 180 while using this tool to completely flip the curve point.

5. You should end up with something like this:

There are actually 4 points in this curve but the last 2 are exactly on top of each other (lower left) to complete the circle.

Convert the curve to a mesh, enter edit mode and merge the start and end vertices using the Alt+M 'Merge' menu.

However, this may cause shading issues as the normals wont know which part of the mesh is 'inside' and which is 'outside'.

• Apologies to all. The subject should have been: “How to join two lines with a surface.” I’ve managed to make a Mobius ring with a square profile. It was creating a surface between two lines that I wanted to know how to do. I think that Ray put his finger on the crux of my problem. When he wrote: “However, this may cause shading issues as the normals won’t know which part of the mesh is 'inside' and which is 'outside'.” I will have a look at that aspect now. Thanks. Stephen – Stephen Aug 8 '14 at 12:08
• Add a plane in Front view;
• in Object mode, RY90;
• In Edit mode, RZ90 (or RXX90 in this case);
• Add an Simple Deform modifier, set type to Twist, set Angle to 180 (or 180*n, depending on how many turns you want).
• Add another Simple Deform modifier, set type to Bend; Create an empty, set it as Origin in the modifier panel, and type 360 as Angle.

• Once the result is expected, AltC -> Mesh from Curve/Meta/Surf/Text to apply all modifiers, then go to Edit mode, W -> Remove Doubles.

Tip: Simple Deform modifiers operate around Local Z Axis. Click to learn more.

example file

• Adjustable subdivision level (by Array);
• Adjustable loop turns (by Bending to 180*n);
• Animatable.

A mobius curve can also be generated by the Extra Objects addon.

• Enable it in Addon list;
• ShiftA -> Curve -> Torus Knot Plus;
• F6, set p=2 q=1, then tweak other parameters as you want.

example file

I'm not sure what kind of Möbius ring you want, so here is a simple method how you can make the simplest one:

1) Add a circle mesh and extrude all vertices along the z axis.

2) Delete one of the edges.

3) With proportional editing (connected) rotate one loose end 90° and the other -90° around the x axis.

4) Select the 4 vertices at the loose end and press f to create a face.

If you want to create a more complex one with more loops, you could try to start with just a plane and repeatedly extrude and rotate one side.