How to revised z value

How to revised z value in order to same result with pit (pitch),at the end
tested for one segment
----------------------------------------------<snip>----------------
32 = (-3.21394 3.83022 275.02)
33 = (-2.5 4.33013 283.614)
34 = (-1.7101 4.69846 292.208)
35 = (-0.868241 4.92404 300.803) >>>I want as like this 35 = (-0.868241
4.92404 1.5)
_$

(defun c:ch (/ seg ang cnt rad pit ele x y z point)
(setq seg 36)
(setq ang (/ (* 2 Pi) seg)) ; (* 2 pi) = 360
(setq cnt 0)
(setq rad 5) ; (setq rad (getdist "\nENTER
NEW RADIUS: "))
(setq pit 1.5) ; (setq rad (getdist "\nENTER
NEW PITCH: "))
(setq ele (/ pit ang))
;(command "3dpoly")
(repeat seg
(setq x (* rad (sin (* cnt ang))))
(setq y (* rad (cos (* cnt ang))))
(setq z (* cnt ele)) ; the problem here
!!!
(setq point (list x y z))
;(command point)
(princ "\n")(princ cnt)(princ " = ")(princ point)
(setq cnt (1+ cnt))
)
;(command "")
(setq cnt nil)
(princ)
)

 

Hi,.... I've got ,and but I got problem to found length of coil (or z
value),how to find it

(defun c:ch (/ seg ang cnt rad pit ele x y z point)
(setq seg 36)
(setq ang (/ (* 2 Pi) seg)) ; (* 2 pi) = 360
(setq cnt 0)
(setq rad 5) ; (getdist "\nENTER NEW RADIUS:
"))
(setq pit 1.5) ; (getdist "\nENTER NEW PITCH:
"))
(setq num 36) ; (getdist "\nENTER NUMBER OF
COIL: "))
(command "3dpoly")
(repeat (+ 1 num)
(setq x (* rad (sin (* cnt ang))))
(setq y (* rad (cos (* cnt ang))))
(setq z (* cnt (/ pit seg)))
(setq point (list x y z))
(command point)
;(princ "\n")(princ cnt)(princ " = ")(princ point)
(setq cnt (1+ cnt))
)
(command "")
(setq cnt nil)
(princ)
)