taper thread cutting programme

[manohar.bulbule]

Sir,
i need taper thread cutting programme in cnc turning center for any npt pipe threads.

[chucker]

Hope this helps
This was made from 3/4 bar stock
O1234(1/8-27 NPT)
N10G54T0202
G50S2000
G96S600M4
G0X.85Z0M8
G1X-.062F.003
G0X.65Z.05
G1Z-1.5F.006
X.7
G0Z.05
X.55
G1Z-1.5
X.6
G0Z.05
X.45
G1Z-.95
X.5
G0.05
X.25
G1Z0
X.373Z-.03F.0015(CHANFER)
X.397Z-.35F.006(THREAD TAPER)
Z-.95
X.48
X.54Z-1.015
Z-1.5
G0X6.Z6.
M1
N20T0303
G97S1000M3
G0X.525Z.5M8
G76P010055Q0010R0005
G76X.36Z-.35P0150Q0050R-0200F.0357
G0X8.Z8.
M30
%

G76- Canned threading cycle

G76 P010060 Q.002 R.0005 (first G76 sets parameters for threading)
G76 X Z P Q F R (cuts the thread)

The first G76 isn't needed but is recommended.
- G76 P Q R

P010060 sets 3 things
- first 2 digits is the amount of finish passes - 01

- second 2 digits is % of the lead or pullout exiting the thread- 00
00 = almost no angle at pullout and 99 = 9.9 leads away start out

- third 2 digits are the angle of infeed - 60
0,29,30,55,60,80 are usable (0-90 is ok)

Q.005 sets the minimum cut amount during threading

R.0005 sets the cut amount of the last pass

The second G76 cuts the thread.
-G76 X.1876 Z.3 P.0302 Q.01 F.05 (R-.002) FOR 1/4-20

X.1876 =Minor Dia. of thread

Z.3 or (W) =The ending Z of the thread

P.0302 =Height of thread in radius (Maj-Min)/2

Q.01 =Amount of the first cut. All the rest of the cuts are calculated.

F.05 =Feed-rate 20 TPI 1/20=.05

R = R is optional for tapered threading. R is the amount of
difference in X from start to finish in Z. When cutting threads
moving Z and X in a positive direction R is a negative value.