Welcome to LinuxCNC.org

I was working on a part that I needed to do a bit of threadmilling on and I ran into a problem. First, here is the entire code I was trying to run. X0, Y0 are the center of the already bored hole (0.875" diameter).

G90
G0 X0 Y0 Z0.1
F10
G1 Z0
G1 X-.282
G2 X-.282 Y0 P10 Z-0.625 I.282 J0
G1 X0
G53 G0 Z0
G53 X0 Y0
M02

But this code gives me an error. It says the P-word can't be used with G2, but the manual I have says that is how to do it.

I was able to get the job done by putting the machine in incremental mode just before the G2 line and using a loop (10X) with a line as follows:

G2 Z-.0625 I0.282

I then put it back into absolute mode and finished the program.

What am I doing wrong with the muti-turn helix? I am using LinuxCNC version 2.4.6.

Thanks,

John B.

For what it is worth it works for me on 2.6
You may want to try it after upgrading to 2.5.

Rick G

109jb wrote:Multi-turn arcs were a new feature in linuxCNC version 2.5.

2.4 docs: www.linuxcnc.org/docs/2.4/html/gcode_main.html#sub:G2,-G3:-Arc

2.5 docs: www.linuxcnc.org/docs/2.5/html/gcode/gcode.html#sec:G2-G3-Arc

I strongly urge upgrading LinuxCNC (You don't need to update Ubuntu or anything else)
The only hassle is that the emc folder becomes linuxcnc, and you will need to change the paths to files in the INI file because of this.

wiki.linuxcnc.org/cgi-bin/wiki.pl?UpdatingTo2.5

Thank you. I will upgrade to 2.5. Should have known it was something simple.

All I did was create a symlink to ~/emc2 called ~/linuxcnc and thereafter ignored it.
No need for editing etc. just carry on using the same stuff as before

regards