Spiral in 3D

Anyone know how to generate a spiral in 3D in ACAD?

I want to model a spring. I figure the first step will be generating a 3D
polyline or spline as a path.

 

It's very simple in 2007 or 2008.
Very difficult with 2006 or before.
Which version do you use?

 

2000 :-(

 

With 2000, one way is to build a torus, cut ir in 4 equal parts. make a
little rotation for parts 2 3 4, another one same angle) for parts 3 and 4
and another one (same angle) for part 4 in such a way to get 1 turn spiral
and copy as many times as necessary.
Problem: it's not a real spiral...

--
hpspt

 

No, it's not:

http://www.cadtutor.net/forum/showthread.php?t=78

 

Hiya

No sweat. Here's the routine, test it a few times to get the feel for
it. I suggest you draw a circle first then pick the circle's center as
a reference point as this routine does not give you one nor can you
pick the center of the spring once created. I hope I made sense.

Dr Fleau

www.cadalyst.com Section: "Get the code"

;Tip1736b: 3DSPIRAL.LSP Create 3D spring

;;; 3DSPIRAL.LSP
;;; Copyright (C) 1993 by Autodesk, Inc.
;;;
;;; Permission to use, copy, modify, and distribute this software
;;; for any purpose and without fee is hereby granted, provided
;;; that the above copyright notice appears in all copies and that
;;; both that copyright notice and this permission notice appear in
;;; all supporting documentation.
;;;
;;; THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT EXPRESS OR IMPLIED
;;; WARRANTY. ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR
;;; PURPOSE AND OF MERCHANTABILITY ARE HEREBY DISCLAIMED.
;;;
--------------------------------------------------------------------------;
;;; DESCRIPTION
;;;
;;; This is a programming example.
;;;
;;; Designed and implemented by Kelvin R. Throop in January 1985
;;; Modified by Bill Zondlo 12/30/99 to be used with SOL_SPRING.LSP.
;;; This program now contains 3DSpiral.lsp only.
;;;
--------------------------------------------------------------------------;

(defun myerror (s) ; If an error (such as CTRL-C)
occurs
; while this command is
active...
(if (/= s "Function cancelled")
(princ (strcat "\nError: " s))
)
(setvar "cmdecho" ocmd) ; Restore saved modes
(setvar "blipmode" oblp)
(setq *error* olderr) ; Restore old *error* handler
(princ)
)

(defun cspiral (ntimes bpoint hfac lppass strad vfac
/ ang dist tp ainc dhinc dvinc circle dv)

(setvar "blipmode" 0) ; turn blipmode off
(setvar "cmdecho" 0) ; turn cmdecho off
(setq circle (* 3.141596235 2))
(setq ainc (/ circle lppass))
(setq dhinc (/ hfac lppass))
(if vfac (setq dvinc (/ vfac lppass)))
(setq ang 0.0)
(if vfac
(setq dist strad dv 0.0)
(setq dist 0.0)
)
(if vfac
(command "_3dpoly") ; start spiral ...
(command "_pline" bpoint) ; start spiral from base point
and...
)
(repeat ntimes
(repeat lppass
(setq tp (polar bpoint (setq ang (+ ang ainc))
(setq dist (+ dist dhinc))
)
)
(if vfac
(setq tp (list (car tp) (cadr tp) (+ dv (caddr tp)))
dv (+ dv dvinc)
)
)
(command tp) ; continue to the next point...
)
)
(command "") ; until done.
(princ)
)

;;;
;;; Interactive spiral generation
;;;

(defun C:3DSPIRAL (/ olderr ocmd oblp nt bp hg vg sr lp)
(setq olderr *error*
*error* myerror)
(setq ocmd (getvar "cmdecho"))
(setq oblp (getvar "blipmode"))
(setvar "cmdecho" 0)
(initget 1) ; bp must not be null
(setq bp (getpoint "\nCenter point: "))
(initget 7) ; nt must not be zero, neg, or
null
(setq nt (getint "\nNumber of rotations: "))
(initget 7) ; sr must not be zero, neg, or
null
(setq sr (getdist bp "\nStarting radius: "))
(initget 1) ; cf must not be zero, or null
(setq hg (getdist "\nHorizontal growth per rotation: "))
(initget 3) ; cf must not be zero, or null
(setq vg (getdist "\nVertical growth per rotation: "))
(initget 6) ; lp must not be zero or neg
(setq lp (getint "\nPoints per rotation <30>: "))
(cond ((null lp) (setq lp 30)))
(cspiral nt bp hg lp sr vg)
(setvar "cmdecho" ocmd)
(setvar "blipmode" oblp)
(setq *error* olderr) ; Restore old *error* handler
(princ)

)
;;;
--------------------------------------------------------------------------;
(princ "\n\tC:3DSPIRAL loaded. ")
(princ)