G76- Canned threading cycle
G76 P010010 Q0020 R0005 (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
P010010 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 - 10
0-99 are usable
Q0020 sets the minimum cut amount during threading .002 but no decimal
(Q00200 for sub inch)
R0005 sets the cut amount of the last pass .0005 but no decimal
(R00050 for sub inch)
The second G76 cuts the thread.
-G76 X.1876 Z.3 P0302 Q0010 F.05 (R-.002) FOR 1/4-20
X.1876 =Minor Dia. of thread
Z.3 or (W) =The ending Z of the thread
P0302 =Height of thread in radius (Maj-Min)/2 (.0302)
(P03020 for sub inch)
Q0100 =Amount of the first cut. All the rest of the cuts are calculated.
(Q01000 for sub inch)
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.