spiral in 3D

[Gregos]

Dear all,

I try and try and try...with no success yet to create a spiral in 3D (not an helix one, just a normal spiral, with a tiny extrusion, in order to re-create a steel ornament of a parisian balcony). And of course, drawing a 2D spiral and extruding it doesn't work (this object can't be extruded...but don't know why).

So here is my question : how do you guys do to create a normal 3D spiral ?

PS : my english is bad. Really sorry for that.

PS : i'm a beginner...so sorry for that dummy question.

[islandmon]

There are many different types of spirals.

Try:

frontview >draw line of any length>select line>goto Menu>Model>3dPowerPack>

'Create Helix-Spiral' > Dialog>insert parameters>draw 3d spiral

[Gregos]

Great trick. So far, i've got my spiral ok (just one like in 2D...but in 3D).

Ok, next, i try to extrude the spiral. Doesn't work. Then, i make a little cube to "extrude it along path". Doesn't work (i guess that it is because the 3D spiral isn't a 3D object).

So i keep this little cube and a "Duplicate along path" with a large number of duplicates. In Wireframe, it look extactly like the thing i want to do. But once rendered, i've got something like a flat surface that fills the space between the turns.

(don't know if what i say makes sense for you...hope so).

Any idea about what i did wrong (i mean, how to get rid off this surface ?)

Edited May 30, 2009 by Gregos

[islandmon]

The 3D Helix-Spiral is a Parametric Object .

Once you get the correct Spiral configuration , you will need to ungroup it.

Result is a NURBS Spiral Path to use with a NURBS Profile for ExtrudeAlongPath.

[Pat Stanford]

You could also draw a "profile" of half of the shape and then do a sweep with a pitch and multiple turns (i.e. 720 degrees, 1440 degrees, etc.)

[Gregos]

Many thanks for your tricks and tips. It works ok now.

I also guess that i now understand why it didn't work before. So thanks a lot for your help.