Dear Answer Man,
Could you help me with a program example for my SL-30? I want to use G76 for a tapered pipe thread without a thread chamfer. It’s a 1.25 NPT thread, 0.875″ deep. Thanks!
The taper is 3/4″ per foot, so:
1) 0.75 ÷ 2 = 0.375
2) 0.375 ÷ 12 = 0.03125
3) 2nd tan–1 of 0.03125 (need a calculator for this) = angle of 1.7899 degrees. This is the taper of the thread. Now determine the minor diameter, which is X1.161 at Z0 (the face of the part). Determine the X position at Z0.5, which is X1.1785, and the X value at Z-0.5, which is X1.1435. Then:
1.1785 – 1.1435 = 0.035
0.035 ÷ 2 = 0.0175, which is your positive I value. The rest should be easy.
O00005 (1-11.5 PIPE THREAD)
G00 X0.95 Z0.5
M23 (or M24 for chamfer off)
G76 X1.1785 Z-0.5 I0.0175 K0.03
You can use a CAM system or the calculator on the Haas Lathe control to make points, lines and angles with which to determine X values.
Sincerely, Answer Man