# Tutorial: How to model self intersecting Möbius strip

Create object like mobius strip is simple, and should be divided into separate operations.

1. ### Step 1:

Draw base circle in sketcher.

2. ### Step 2:

Use sweep feature to create first part of revolving surface. For trajectory select half-circle arc. Choose option "Allow change section along trajectory".

3. ### Step 3:

Draw middle line and assign equation to angle dimension by using Tools-> Dimensions command, and write sd9=trajpar*135, where sd9- is name of angle dimension in section.

4. ### Step 4:

You should get a surface that smoothly rotates at 135°.

5. ### Step 5:

Do second sweep as first. Choose second arc of circle for trajectory, equiation for angle dimension in section must be like 45+trajpar*135. So we get 2 surface with a total rotation of 270°. (135°+135°=270°)

6. ### Step 6:

Do auxiliary point on circle. Make sure you select all circle not arc.

7. ### Step 7:

Create hole by using extrude feature with options (surface and cut 2-side)

8. ### Step 8:

Merge surfaces.

9. ### Step 9:

Make copy of auxiliary point and moving it by angle 360/15.5=23,225806451612903225806451612903 (15.5- is quantity of holes that are placed on the surface), then create axis and plane through point. Axis must be perpendicular to surface, plane must be perpendicular to axis.

10. ### Step 10:

Create hole by using extrude feature with options (surface and cut 2-side)

11. ### Step 11:

Group 4 last features (moved point, axis, plane, extrude), and make array by angle dimension.

12. ### Step 12:

Select this 'cheese surface'. Press ctrl+c then ctrl+v to copy and paste surface. Confirm copying. Select copy, and again copy it. And use Special paste to apply move/rotate option. rotate surface among Z-axis by 180°.

13. ### Step 13:

Merge two surfaces.

14. ### Step 14:

Give thikness.

Make rounds.