So, I've been cutting all kinds of stuff on my router with multiple programs (1 per tool), but now that I got the basic Mach4 manual tool change working, I am trying some programs with 2 tools. Both times I've had the same problem where the program pauses and says to load tool 2, so I do so, then find the top of the part with the new tool using jogging, using a piece of .3mm shim and then offsetting .3mm and hitting Zero Z, but then when I resume the program, the height is off, too high.

The program is supposed to cut all around a 2mm thick panel and go Z-2.1 (I opened the Gcode and verified), but I watched while the prgram was running and it was at some weird number like Z -1.2475. I don't know why it would do that. Even if I had forgotten to re-zero, wouldn't the program still just go to Z-2.1 and then have the offset be all screwed and possibly crash? Where the hell did it get -1.2475 from? It's not even in the code.

Any help much appreciated!

Did you ever resolve this problem. I just had the same problem. I swapped the tool and touched off and manually reset the Z DRO to .471. When I hit cycle start Z was supposed to go to .335 but went to -1.468 and obliterated the tool and the entire setup. Is there something else that needs to be done on a manual tool change? Some setting somewhere that needs to be checked?