3D spiral

Is it possible to extrude a circle or any shape along a 3d spiral as for
a coil spring or a handrail for a spiral staircase.

I have tried solids and surfaces but nothing works.

Any help would be appreciated.

Thanks
Richardb

 

HiHo;
Use "Rhino" from www.mcneel.com

 

Hi Richard,

thank you for your interest in my ideas.

some times ago I started to develop programs to make SOLIDs from
surface-models, i.e. to get a general solution for the "unexplode"-command
for SOLIDs.
And now I've found a first solution for SOLIDs bounded by plane faces
(REGIONs).
But for your problem about untwisted profiles it is quite enough to use my
RS2S.lsp.
Using it you can create the SOLID laying between 2 RULESURF-surfaces having
equal SURFTAB1-values.
I take the first 4-point- surface( it must not be a plane one) and the
corresponding 4-point-face from the second RULESURF-surface and create the
HEXAEDER laying between them. It consists of TETRAEDERs and PENTAEDERs.
Finally I unite these single SOLIDs and the results you can see from the
appended examples- see especially the GELAENDER1.DWG (i.e. railing).
The accuracy is depending on the value of the SURFTAB1, i.e. it is up to
256.
Beeing correct I have to say that you really cannot create twisted surfaces
in AutoCAD as I know - depending on the ACIS-kernel but the results got by
triangulation seem to be sufficient.
Other Informations you will see from my www.black-cad.de ( unfolding ,
PEDIT3D).
Regards from
good (c)old Germany
Jochen
PS. The attachment was not transferred
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