;TIP598B.LSP   Draw Channel Section   
;revised

(defun C:CHNNL2 (/ CHFL CHD DLN CTL OS )
  (setq  CHD (strcase (getstring "Channel size, ie 12x30: ") T)
        CHFL (open "C:/ACAD/LISP/CHNNL.TXT" "r")
         DLN (strlen CHD)
         CTL (read-line CHFL)
  )
  (while (and CTL (/= CHD (substr CTL 1 DLN)))
    (setq CTL (read-line CHFL))
  )
  (close CHFL)
  (if (not (member CTL '(nil "")))
    (if (= CHD (substr CTL 1 DLN))
      (DRCHN CTL)
    )
    (prompt "Channel size not found\n")
  )(princ)
)
(defun DRCHN (CTL)
  (setq IP  (getpoint "Pick insertion point ")
        DIS (* 0.08748 (/ (- BF TW) 2))
        NTH (/ pi 2)
        WST pi
        STH (* 3 (/ pi 2))
        EST 0.0
        PT1 (polar IP NTH BF)
        PT2 (polar PT1 EST D)
        PT3 (polar PT2 STH BF)
        PT4 (polar PT3 WST (- TF DIS))
        PTA (polar PT2 STH TW)
        PT5 (polar PTA WST (+ TF DIS))
        PTB (polar PT1 STH TW)
        PT6 (polar PTB EST (+ TF DIS))
        PT7 (polar IP EST (- TF DIS))
  )
  (command "PLINE" IP PT1 PT2 PT3 PT4 PT5 PT6 PT7 IP "")
  (command "FILLET" "R" (- (- TF DIS) 0.001))
  (command "FILLET" PT4 PT4)
  (command "FILLET" PT7 PT7)
  (command "FILLET" "R" "0.125")
  (command "FILLET" PT5 PT5)
  (command "FILLET" PT6 PT6)
)