Taper thread milling

[chinnbob]

I am working on programming a NPT threaded hole. Is there a c-hook or macro available for this type of operation? Or would it be easier to draw the helix and then toolpath it? Any help will be appreciated. Thanks.

------------------

Brian Chinn

Mastercam Version 8

Pentium 4-1.4 Ghz

384 Meg RAM

Windows 2000 - SP1

[Allan]

Thread milling of an NPT would normally be done with a form tool. If you are trying to do it with a single flute cutter then you need to construct the helix. Try using the thelix.dll c-hook. (Good Luck)

Your best bet is to get a correct multi tooth form cutter.

Allan

[biss03]

if i'm understanding your question, this is what i do when i need to do a npt threadmilling operation, i use a tapered insert on the tool. It has either one or two inserts on the tool and each insert has 7 or 8 teeth on it that are tapered per the specs required. this eliminates the need to do it manually.

hope this helps.

[tboiesan]

By using a tapered insert does not eliminate the need for helical spiral out on taper of NPT thread. It only allow s to mill in stages or to ensure recutting of profile in case the first insert tooth is damaged.

To solve the problem I developed a simple macro routine for Fanuc type control.

This routine can be used like any other canned cycle by using a macro call: (G65 for single holes or G66 + G67 for multiple holes) The routine allows for setting all necasary parameters of the thread on calling line:

(MILL FROM Z LEVEL)

(Z=#26 FINAL LEVEL)

(R=#18 RAPID DEPTH = REFERENCE)

(Q=#17 THREADS/INCH)

(U=#21 SIZE OF THREAD AT R LEVEL)

(D MUST BE SET IN MAIN PROG)

(F MUST BE SET IN MAIN PROG)

The macro Routine uses radius compensation in the control.

If interested please send me a message

 

[gary dunn]

there a chook called Thelix that works really good.

[Allan]

Here is a macro that will mill the pipe thread with a single flute cutter. You still need a tapered hole!

In the main program use.

G65 P9026 U0. W0. A.375 R5. E10. Z-.5 V18. F10.

This is the sub/macro

O9026 (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

 

[chinnbob]

Thanks for all the help!