A taper thread milling Custom Macro

by Mitchell Callan of Fuller precision Inc.

I have written a macro that machines a taper thread with a single point thread milling cutter. This will help anyone that doesn't have a true pipe thread mill. Also, it forms a spiral motion, which is necessary for taper thread milling even if a true taper thread mill is used. It will cut any pitch or size of pipe threads

In main program:

• G65 P9000 U0. W0. A.375 R5. E10. Z-.5 V18. F10.

Custom macro:

• O9000 (PIPE THREADS)

• (U IS X LOCATION)

• (W IS Y LOCATION)

• (A=STARTING RADIUS)

• (R=NUMBER OF MOVES PER CIRCLE)

• (Z=DEPTH)

• (E=NUMBER OF PASSES [thickness / pitch])

• (V=THREADS PER INCH)

• (F=FEED)

• #3=0.0

• #10=360 / #18

• #109=#10

• #110=1 / #22

• #111=0.0625 / #22

• #3=#18

• G00 X#21 Y#23

• G01 Z#26 F#9

• #19=#1 + #21

• G01 X#19 Y#23 F#9

• N2 #26=#26 + #110 / #109

• #24=COS[ #3 ] * #1

• #25=SIN[ #3 ] * #1

• #24=#24 + #21

• #25=#25 + #23

• G01 X#24 Y#25 Z#26 F#9

• #3=#3 + #18

• #1=#1 + #111 / #109

• IF [ #3 LE 360.00000 * #8 ] GOTO2

• G01 X#21 Y#23 F10.

• G00 Z1. M09

• M99