I downloaded the npt_pipe.ngc program this morning and it worked perfectly on my CNC Lathe to cut 1/2"-14 NPT threads. Thank you for sharing this program.
Listed below are a few minor tweaks that I had to make to get the program to run on my setup. I hope this helps others.
1) Double click on the attached file in the forum to open the file in the browser. Then, Select All and Copy. Open NotePad in Windows or Kate in Linux and then Paste in the entire program file. Select, Save As and Title it npt_pipe.ngc.
2) Delete the First Program Line..... o<npt_pipe> sub, OR Comment It Out
using parethesies..... (o<npt_pipe> sub).
3) Delete the Last Program Line...... o<npt_pipe> endsub, OR Comment It
Out using parethesies..... (o<npt_pipe> endsub)
4) About 11 Program Lines down, there is a list of variables = #1, #2, #3 etc. as shown below.
#<_OutsideDiameter> = #1 (Nom or Act Dia, D)
#<_TPI> = #2 (=0 TPI, 0 for auto)
#<_First_Cut_Depth> = #3 (=0.015 First Cut)
#<_Minimum_Cut_Depth> = #4 (=0.003)
#<_X_Clearance> = #5 (=0.075 X clearance)
#<_Z_LeadIn> = #6 (=0.250 Z Leadin)
#<_TipRadius> = #7 (=0.003 Tip Radius)
#<_Spring_Passes> = #8 (=1 Spring Passes)
#<_CompoundSlideAngle> = #9 (=29.5 Angle, 0-30)
Replace the #Numbers with your parameters and save the file. My parameters for a 1/2-14 NPT thread were as follows:
#<_OutsideDiameter> = 0.5 (Nom or Act Dia, D)
#<_TPI> = 0 (=0 TPI, 0 for auto)
#<_First_Cut_Depth> = 0.006 (=0.015 First Cut)
#<_Minimum_Cut_Depth> = 0.002 (=0.003)
#<_X_Clearance> = 0.075 (=0.075 X clearance)
#<_Z_LeadIn> = 0.0625 (=0.250 Z Leadin)
#<_TipRadius> = 0.003 (=0.003 Tip Radius)
#<_Spring_Passes> = 1 (=1 Spring Passes)
#<_CompoundSlideAngle> = 0 (=29.5 Angle, 0-30)
5) Open the saved .ngc file in Linuxcnc (i.e. Linuxcnc configured for a Lathe.)
Good luck. Barry
