Hi, this is my first post. I am relatively new to cnc.

I have been using mach3 for about 4 months and have successfully completed a few different projects. I am a woodworker so have been cutting several things on my 3 axis machine (i have 4th axis but not yet set up). I currently use 2 cad/cam programs - fusion 360 and something called f-engrave. The problem i have is that all of a sudden, when posting the g-code using f360, when the cycle starts, it sends the spindle down on z axis into the workpiece and keeps going until I hit stop (spindle not running). If I 'go to zero' the spindle goes to correct position. I have identified the issue in the code;

(1001)
(T1  D=12.7 CR=0. - ZMIN=-8. - FLAT END MILL)
G90 G94 G91.1 G40 G49 G17
G21
G28 G91 Z0.
G90

(12.7MM REMOVE CENTRE)
M5
M9
T1 M6
S19000 M3
G54
M9
G0 X2.326 Y34.61
G43 Z15. H1
Z5.
G1 Z3.769 F1500.
X2.325 Y34.613 Z3.672


So looking at the code, if I delete - G28 G91 Z0. then it appears to work fine. Unfortunately there was also the same line at the end of the file but I didn't notice it, and when I just ran this file it went right through the workpiece and into the aluminium worked underneath.

This file is in the same format as all my other f360 g-code files and these all ran fine in the past, but not now. This makes me think that a setting must have changed in mach3 - is anyone able to  help me solve this issue please?


Many thanks in advance to any help

Hi,
this thread covers exactly this issue:

http://www.machsupport.com/forum/index.php/topic,37114.0.html

Craig

Hi Craig, thanks very much for pointing me in the right direction

Hi,
use the 'Search' function, if you try several searches with sufficiently refined search terms you will find examples of what you are looking for. As it turns out the thread I linked you to
is current...you didn't have to look far.

Craig

I had the same problem when I started using Fusion and mach, it was caused by the G28 code and not having my home settings set up properly. You can turn off "use G28" in the post process dialog box in Fusion.