Hi, I have a CNC lathe that I converted to run on mach 3 but I'm having some issues with it. When I type in the G-codes manually one line at a time the lathe performs exactly as it should, but when I run a program it looses its place by quite a large amount - 10mm or so. I really need to get it sorted because manual machining is taking me too long. Help would be appreciated, thanks

Below is a bit of the code.
G21 G40
G00 Z5 X30
G01 Z0 F100
G01 X-2 F50
G00 Z5
G00 X25 Z2
G01 Z-38 F100
G00 X30
G00 Z5
M01
G00 X0
G00 X24 Z2   All ok until it gets to here, it only moves to about x12 but says x24 in software, I have to hit e-stop otherwise it would crash
G01 Z-38 F100
G00 X30
G00 Z5
M01
G00 X0
G00 X23 Z2 Does exactly the same here losing a further 10mm
G01 Z-38 F100
G00 X30
G00 Z5

Sounds like you may be looseing steps to me. Try detuning your accel and velocity by 50% and see if that helps.

Brett

Hi, If I type in all of this G code line by line then it does it all fine, when it is put all in one program it does not. I can type G0 Z0, Z500, Z0, X200, X0, X200 all in the manual command and it wont lose a single step, put this into a program and it will lose several hundred steps.

Can you attach your xml please, will see if I can replicate your problem here with your settings.
Hood

I will attach the xml tomorrow, software is on different computer to what I'm using at the moment.

Ok no problems getting late here anyway
Hood

Im thinking it may be loosing then when running in auto because you are changeing directions so fast.  I think inertia and accel are what you are fighting.

Brett

also you may try turning off the viewport.  this is an issue with very large g codes that i have run in the past,  now its standard practice to always turn off the viewport before pressing GO