[Matyi]

Hello!
I have a problem with a small program part, whre I use tool nose radius compensation. the tool simply does not want to go where I want
Here is the program part:

T0707
G50S1500
G96S180M3
G0X43.Z3.
G1G41X42.6Z3.F.1M8
G1Z0. <-----------------on the graph here it goes in Z-.234
G1X42.Z-.3
G1Z-2. <---------------here it goes right (Z-2.)
G1X27.6 <------here x is wrong with the same value as z before
G1X27.Z-2.3 <-------both are wrong, same value as before
G1Z-13. here it goes in z-13.4

Couldn`t find out what the problem was. Tool nose radius is 0.4mm.
Where does it get that 0.234 value? And in six`th line why does it go in z-2. as programmed. Could anyone help me here? Am I missing something at the previous settings? Tool measurements etc.
Thanks anticipated!

[beege]

First, I would have used G42 on MY lathe, a Hardinge CHNCII+.
Second, have some movement in Z when turning on TNRC; you have Z3. on the prior line, and Z3. on the lie of TNRC

It just seems that the control is trying to comp on the wrong side of the angled lines.

[theemudracer]

turn cutter comp on and feed to the start point.

G0X---Z--- (RAPID TO .100 OF STARTING POSITION)
G42GO1X---Z----(START POSITION FOR RADIUS)
G01X---Z---R--- (CUTTER COMP ON)
G01X---Z--- (MUST HAVE LINEAR FEED AFTER TO TURN CC OFF)
G40 (TURN CUTTER COMP OFF)

[dcoupar]

Sounds to me like it's compensating correctly (see attached .jpg file) for what you've programmed.

Try this one:

T0707
G50S1500
G96S180M3
G0X43.Z3.
G1G41X43.Z.2F.1M8
G1X42.Z-.3
G1Z-2.
G1X27.6
G1X27.Z-2.3
G1Z-13.
G1X26.1
G0G40Z3.0

[adamant]

Nice graph dcoupar.

What software did you use?

[dcoupar]

QuickCAD... no longer made, but I still love it.

[JH-Q]

I used to have similar problems on most of my programs with compensation. Then one day, an older machinist told me good way to ensure the compensation goes right. If turning external, begin at least 2* radius of the tool tip +0.2mm smaller (X-axis) than the first geometrical point is. If turning internal, do the same, but begin with bigger diameter. Since being told that, the compensation has been working just as it should be in all of my programs.

Like this in your case:

T0707
G50 S1500
G96 S180 M3
G0 X43.6Z3.
G1 G41 Z0. F.1 M8
G1 X42.6
G1 X42.Z-.3
G1 Z-2.
G1 X27.6
G1 X27. Z-2.3
G1 Z-13.