Tool change position

[Sualc]

I speak about milling.

If you use one CAM to make yours tool paths in gcode you can make one gcode for each tool and send each file to your cnc. But, then you lose your WPos between tools.

Of course you can have only 1 gcode file with all your used tools paths (different tools each one). If the 1st tool path has removed part of your workpiece, its possibly difficult to find again the WPos.

(*) Specially the old Z0 in WPos, because is probable you have not anymore material there . Because the tools have not the same height the Z WPos need to be adjusted between tools changes. But never needed to adjust the X and Y WPos between tools changes.

OMG! is very difficult for me to expose all this in English.

Here I go: grbl ignore the Tx gcode statement atm.

What I propose is:

• grbl get one Tx gcode line.
• wait to finish the last moves in fifo.
• move the Z to up (clearance safe) position. (Z limit will be nice because the limit switch will be there for all ppl I think).
• stop the spindle (only when Zpos is already UP, this is to allow the tool coming out from the workpiece rotating the tool at the current speed)
• move X and Y to the "Tool change" coordinates. NEW (?)
• Send "Tool = " & x to serial com. You must to know what tool is x !
• wait when there the user change the tool and perhaps the spindle speed if not auto)
• user adjust the new Z position.
• user send a "continue" command (~ if am right)
• gcode continue with the path for the new tool.
• Optional = grbl go to Mpos 0,0,0 if all the work is finished. (Perhaps NEW also)

Because (*) the Z0 WPos may/must to be defined at the lowest Z position of the workpiece (working table + protection thing/foil hight). I use 2mm wooden plate to protect the martyr by the cut all moves. Then my Z0 will be ever working table (martyr) + 2mm wooden plate.

Of course is needed to make the same in the CAM software. This means WPos in CAM will be X left side, Y front side and Z the lowest plane of the workpiece.

This is only one proposition. I am sure not all ppl with agree with this.

[chamnit]

Right now, grbl doesn't support tool changes or tool offsets. It not a high priority and will likely not be install for a while or ever. Depends on where we are at the end and if we have space to do it. There are a number of ways to find this by old traditional methods, which I'm not going to go into. It just takes a little ingenuity to find something that works for you.

[csdexter]

The only help I have for you is my version of script/stream.py which looks for M06 and pauses gracefully, waiting for you to change the tool and then press ENTER.

I used it with Eagle's PCB2GCODE which inserts a traverse move to a configurable tool change position (and a spindle stop, of course) before each M06 so the only thing you need to do is literally, change the tool and press ENTER.

Maybe it helps :-)