Duct elbow

[mdbdesign]

We got large project for aluminum duct system ranging Ø from 100 to 1000 mm involving lots of elbows My question is: is there somewhere lisp that can draw side view of elbow with only user input as: duct OD, # of segments and elbow degree.
Please help

[Lee Mac]

Try this for starters:

(defun c:duct (/ *error* oVars vLst dPt dOd Segs dAng vEnt i PntEve PntOdd
             cAngE sPtE ePtE cAngO sPtO ePtO last_pt1 last_pt2)
  (defun *error* (msg)
    (if oVars (mapcar 'setvar vLst oVars))
    (princ (strcat "\nError: " (strcase msg))) (princ))
  (setq vLst '("CMDECHO" "OSMODE")
    oVars (mapcar 'getvar vLst))
  (if (and (setq dPt (getpoint "\nSelect Point for Elbow: "))
       (not (initget 7)) (setq dOd (getdist "\nSpecify Duct OD: "))
       (not (initget 7)) (setq Segs (getint "\nSpecify No. of Segments: "))
       (setq dAng (getreal "\nSpecify Elbow Angle: ")) (< 0 dAng 360))
    (progn
      (mapcar 'setvar vlst '(0 0))
      (command "_arc" "_C" (polar dPt (/ pi 2) dOd) dPt "_A" (rtos dAng))
      (setq vEnt (vlax-ename->vla-object (entlast)) i 0.0 inc (/ (vla-get-ArcLength vEnt) Segs))
      (while (or  (setq PntEve (vlax-curve-GetPointatDist vEnt i)
            PntOdd (vlax-curve-GetPointatDist vEnt (setq i (+ inc i)))))
    (setq cAngE (+ (/ pi 2) (angle '(0 0 0) (vlax-curve-getFirstDeriv vEnt
                         (vlax-curve-GetParamAtPoint vEnt PntEve)))))
    (command "_line" (setq sPtE (polar PntEve cAngE 4.0)) (setq ePtE (polar PntEve (+ pi cAngE) 4.0)) "")
    (if (and last_pt1 last_pt2) (progn (command "_line" last_pt1 sPtE "") (command "_line" last_pt2 ePtE "")))
    (setq cAngO (+ (/ pi 2) (angle '(0 0 0) (vlax-curve-getFirstDeriv vEnt
                         (vlax-curve-GetParamAtPoint vEnt PntOdd)))))
    (command "_line" (setq sPtO (polar PntOdd cAngO 3.0)) (setq ePtO (polar PntOdd (+ pi cAngO) 3.0)) "")
    (command "_line" sPtE sPtO "") (command "_line" ePtE ePtO "")
    (setq last_pt1 sPtO last_pt2 ePtO)
    (setq i (+ inc i)))
      (vla-put-Color vEnt acblue))
    (princ "\n<!> Points Specified Incorrectly <!>"))
  (mapcar 'setvar vLst oVars)
  (princ))

[Lee Mac]

My apologies, this is better:

(defun c:duct  (/ *error* oVars    vLst dPt dOd Segs dAng vEnt i PntEve
           PntOdd cAngE sPtE ePtE cAngO sPtO ePtO last_pt1 last_pt2)
  (defun *error*  (msg)
    (if    oVars (mapcar 'setvar vLst oVars))
    (princ (strcat "\nError: " (strcase msg))) (princ))
  (setq    vLst  '("CMDECHO" "OSMODE")
    oVars (mapcar 'getvar vLst))
  (if (and (setq dPt (getpoint "\nSelect Point for Elbow: "))
       (not (initget 7)) (setq dOd (getdist "\nSpecify Duct OD: "))
       (not (initget 7)) (setq Segs (getint "\nSpecify No. of Segments: "))
       (setq dAng (getreal "\nSpecify Elbow Angle: ")) (< 0 dAng 360))
    (progn
      (mapcar 'setvar vlst '(0 0))
      (command "_arc" "_C" (polar dPt (/ pi 2) (* 1.5 dOd)) dPt "_A" (rtos dAng))
      (setq vEnt (vlax-ename->vla-object (entlast)) i 0.0 inc (/ (vla-get-ArcLength vEnt) Segs))
      (while (setq PntEve (vlax-curve-GetPointatDist vEnt i))
    (setq cAngE (+ (/ pi 2) (angle '(0 0 0) (vlax-curve-getFirstDeriv vEnt
                (vlax-curve-GetParamAtPoint vEnt PntEve)))))
    (command "_line" (setq sPtE (polar PntEve cAngE (/ (+ dOd (* inc 2.0)) 2.0)))
         (setq ePtE (polar PntEve (+ pi cAngE) (/ (+ dOd (* inc 2.0)) 2.0))) "")
    (if (and last_pt1 last_pt2) (progn (command "_line" last_pt1 sPtE "") (command "_line" last_pt2 ePtE "")))
    (if (setq PntOdd (vlax-curve-GetPointatDist vEnt (setq i (+ inc i))))
      (progn
        (setq cAngO    (+ (/ pi 2) (angle '(0 0 0) (vlax-curve-getFirstDeriv vEnt
                              (vlax-curve-GetParamAtPoint vEnt PntOdd)))))
        (command "_line" (setq sPtO (polar PntOdd cAngO (/ dOd 2.0)))
             (setq ePtO (polar PntOdd (+ pi cAngO) (/ dOd 2.0))) "")
        (command "_line" sPtE sPtO "") (command "_line" ePtE ePtO "")
        (setq last_pt1 sPtO last_pt2 ePtO i (+ inc i)))))
      (vla-put-Color vEnt acblue))
    (princ "\n<!> Points Specified Incorrectly <!>"))
  (mapcar 'setvar vLst oVars)
  (princ))

[mdbdesign]

Lee, it got any restriction about Autocad version for this rutine?
See dwg.

[Lee Mac]

Not restrictions, I just thought you wanted ducting like this:

[Lee Mac]

Ok, I've given you an "adjustment menu" at the top of the LISP, play around with it til your hearts content

(defun c:duct  (/ *error* oVars    vLst dPt dOd Segs dAng vEnt i PntEve PntOdd
          cAngE sPtE ePtE cAngO sPtO ePtO last_pt1 last_pt2 Cent str)

  ;; ==== Adjustments ====

  (setq Cent T) ; Duct Centreline

  (setq str T) ; Straight/Corrugated Duct (T = Straight, nil = Corrugated)

  ;; =====================


  (defun *error*  (msg)
    (if    oVars (mapcar 'setvar vLst oVars))
    (princ (strcat "\nError: " (strcase msg)))
    (princ))
  (setq    vLst  '("CMDECHO" "OSMODE")
    oVars (mapcar 'getvar vLst))
  (if (and (setq dPt (getpoint "\nSelect Point for Elbow: "))
       (not (initget 7))
       (setq dOd (getdist "\nSpecify Duct OD: "))
       (not (initget 7))
       (setq Segs (getint "\nSpecify No. of Segments: "))
       (setq dAng (getreal "\nSpecify Elbow Angle: "))
       (< 0 dAng 360))
    (progn
      (mapcar 'setvar vlst '(0 0))
      (or (and str (setq j 0.0)) (setq j 1.0))
      (command "_arc" "_C" (polar dPt (/ pi 2) (* 1.5 dOd)) dPt "_A" (rtos dAng))
      (setq vEnt (vlax-ename->vla-object (entlast))
        i     0.0
        inc     (/ (vla-get-ArcLength vEnt) Segs))
      (while (setq PntEve (vlax-curve-GetPointatDist vEnt i))
    (setq cAngE (+ (/ pi 2) (angle '(0 0 0) (vlax-curve-getFirstDeriv vEnt
                (vlax-curve-GetParamAtPoint vEnt PntEve)))))
    (command "_line" (setq sPtE (polar PntEve cAngE (/ (+ dOd (* j inc 2.0)) 2.0)))
         (setq ePtE (polar PntEve (+ pi cAngE) (/ (+ dOd (* j inc 2.0)) 2.0))) "")
    (if (and last_pt1 last_pt2)
      (progn (command "_line" last_pt1 sPtE "") (command "_line" last_pt2 ePtE "")))
    (if (setq PntOdd (vlax-curve-GetPointatDist vEnt (setq i (+ inc i))))
      (progn
        (setq cAngO    (+ (/ pi 2) (angle '(0 0 0) (vlax-curve-getFirstDeriv vEnt
                              (vlax-curve-GetParamAtPoint vEnt PntOdd)))))
        (command "_line" (setq sPtO (polar PntOdd cAngO (/ dOd 2.0)))
             (setq ePtO (polar PntOdd (+ pi cAngO) (/ dOd 2.0))) "")
        (command "_line" sPtE sPtO "")
        (command "_line" ePtE ePtO "")
        (setq last_pt1 sPtO last_pt2 ePtO i (+ inc i)))))
      (if Cent (vla-put-Color vEnt acblue) (vla-delete vEnt)))
    (princ "\n<!> Points Specified Incorrectly <!>"))
  (mapcar 'setvar vLst oVars)
  (princ))

[mdbdesign]

Will try at home. Big thanks Lee

[Lee Mac]

Will try at home. Big thanks Lee

No probs, I had fun working on it

[mdbdesign]

Perfect.
Lee, I will explain...
on attached dwg

[Lee Mac]

Ok, will have a look when I get home