Hi,

I purchased Mach 3 yesterday having re-built my CNC machine and upgrading all the controllers, of course my old software was no good as it was tailored to the old hardware..

I have just tried to do some milling and the strangest thing is happening, Mach3 starts from zero but then drops in the Z axis before cutting. This is of course ruining my piece because it's milling right through it..

Does anyone know what is going on? The code is coming straight from Solidcam and I had no problems before, here is the initial G-Code.


Thanks

%
O5000 (P_CONTOUR_T1.TAP)
( MCV-OP ) (15-JAN-2014)
(SUBROUTINES: O2 .. )         
G90 G17
G80 G49 G40
G54
G91 G28 Z0
G90
M01
N1 M6 T1
(TOOL -1- MILL DIA 2.0 R0. MM )
G90 G00 G40 G54
G43 H1 D31 G0 X24.984 Y9.94 Z10. S1000 M3
M8
(---------------------)
(P-CONTOUR-T1 - POCKET)
(---------------------)
   X24.984 Y9.94 Z10.
   Z2.
G1 Z-1. F33
   X29.784 F99.999
   Y10.539
   X20.184
   Y9.94
   X24.984
   Y9.24
   X30.484
   Y11.239
   X19.484
   Y9.24
   X24.984
   Y8.54
   X31.184
   Y11.939
   X18.784
   Y8.54
   X24.984
   Y7.84
   X31.884
   Y12.639
   X18.084
   Y7.84
   X24.984
   Y7.14
   X32.584
   Y13.339
   X17.384
   Y7.14
   X24.984
G0 Z10.

This line is telling Mach to set the height offset and go to Z10

G43 H1 D31 G0 X24.984 Y9.94 Z10. S1000 M3

Then Mach is told to rapid to Z2 and then this line tells Mach to go to Z-1 with a feed of 33 units per min.

G1 Z-1. F33



So looks to me like Mach is doing as it is told. Maybe you are used to having Z0 as fully down, seems some router guys work that way instead of Z0 being the top of the work as is the way with most people with mills.


Hood

Hi Hood,

Yes, that makes sense now. It's actually going where it should although that is actually the wrong way... I will need to change it from Z10 to Z-10 in Solidcam and see if that does it...

Thanks.

You would normally set zero as the top of the work, ie jog down and touch off then press the zero at the side of the Z Axis DRO. Alternatively you can use a slip gauge or feeler between the work and cutter then enter the thickness of the feeler direct into the DRO. That would tell Mach the cutter is that value above the top of the work.
Hood

I'm not sure that is it, have you tried loading it?

Zero should be top left and always has been... Surely Z10. is up and Z-1.0 is down? It's cutting fine and the work is t right way up it just seems to go down on Z0

Ok, so this is very strange!

I have just installed Mach3 on my windows 7 Design PC so I don't have to keep going back and forth and guess what, it's ok on this version... Same code, look at the difference.

If the DRO reads 10 and you then command or jog to zero the axis should move down, is that happening?

Hood

This is all happening before the Z10, it's in the G commands it's doing it. Seems to run right on the win 7 installl but the XP install has this initial drop, both running the same G-Code..

I can only assume that there is a setting in Mach 3 that I have checked as I have only just installed the version in win7 so it's as it comes.  Any ideas?

so, just to clarify...

The top image is of the CNC machine install of Mach3 where it has this drop clearly visible on the 3D tool path window.

The bottom image is my design PC running the same version of Mach3 but the tool path is how would expect to see it, it starts a zero and goes up to Z10 before cutting.

There is something wrong with the setup on the version on the CNC PC and I don't know how to correct it.