# How to create a twisted and folded bench

I have a project coming up where we have a bench (probably formed from a twisted wood) which curves and flows in x,y,z directions. What would be the best workflow and commands to use to create such a bench that well later on be 3D-Printed?

Thanks,
Lior

It looks to me like building curve â€śrailsâ€ť that are the same length and stay the same distance apart could be used with a 2-rail sweep.

That makes sense, but how am I supposed to create the curves?

I suppose Iâ€™d start with running some tutorials from the Learn page to get youy head around the NURBS modeling process, and working in multiple views.

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Hi @LiorGold,

I think Iâ€™d take a different approach - creating these swirling curves, making them nice and keeping them at a constant distance will be head-explodingly difficult.

Rather than trying to create the edge curves I would create a few lines running perpendicularly between them, and loft those lines to create a surface. Like this:

1. Create a box defining the space the bench will occupy, so you have something to ground your placement.

2. Place a line representing the depth of the seat from front to back on the centreline where you want the surface to be. Copy that line and place it where you want the flat part of the seat to end. Place another copy where there is a significant change of direction and rotate and move it to reflect the desired direction. Place and orient more lines until you have represented all the significant orientations. If you are seeking a symmetrical bench you can set out one side and use mirror to get the second.

(Note: It helps to annotate all the ends that will lie on one of the two edges with a point so you are clear which end is which in the next step.)

3. With History turned on, loft the lines to create a surface. Make sure you select them in the correct order and all near the correct end.

4. Adjust the surface by moving and rotating the lines. Because you had history on for the loft the surface will follow the changes in the lines. Apart from improving the aesthetics of the surface, make sure you adjust out any self intersections.

5. Once you are happy with the surface, offset it to create a solid with the desired thickness.

6. You have a swirling bench.

If you are likely to need to do a lot of tweaking you might find history an insufficient tool (for example, using offset to create thickness breaks history so once you do that you canâ€™t go back (well, you could if you save a copy of your model beforehand). In that case you will be better off using Grasshopper to control the positioning and orientation of your lines and the surface generation.

HTH
Jeremy

Reference:

Pierre Renart
mĂ¶bius bench

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my guess - this is a special case of a developable surface.
the unrolled pattern is a rectangle.
the two edges are parallel but the rulings have different lengths.

â€¦ if this is the case - it will be more a computational problem then a pure modelling taskâ€¦

rectangel_developable_tp.3dm (3.0 MB)

â€¦ played around a bit moreâ€¦
seams like real world physical models are easier then modelling bended stripes in 3dâ€¦

@LiorGold is your question solved somehow ?