tool changing

hi all. new problem (i know, i know, there are no problems, just solutions waiting to be discovered)....

i am using autodesk artcam along with linuxcnc to get my projects done.
my cnc does not have a tool changer. so when the gcode encounters a tool change, it stops dead where it is, asks for the tool to be changed, and displays the "continue" button. so here is the problem:

where it stops is generally too low to change the bit. in order to change the bit, i have to "stop" the program, raise it with "page up", and change the bit. i then re-home all the axis to zero. when i try to continue, it starts from the top of the gcode (which of course is bad because the wrong bit is in the spindle).
i tried highlighting the gcode line after the requested tool change and restarting, but it still goes back to the the first line of code.
so, my questions are:

1) what is the correct procedure to change a bit when requested.
2) how does one (if at all possible) jump to different points in the gcode execution (for instance to re-cut a given vector)

jacques

anyone??

You need to change your tool change location

This will be in your .INI file If it is not in your .INI file add it, it will send the quill or head to the max Z position for the tool change.

check out the EMCIO section in the INI configuration

linuxcnc.org/docs/2.6/html/config/ini_co...ml#sub:EMCIO-Section


In AXIS you can right click in the line of Gcode you want to start at and it will say "run from here"

1) any special place in the ini file?
2) what about homing the z after the tool change?

jacques

mine is in my EMCIO section

As for the homing after Z....you wont unhome the machine on a tool change. Do you mean setting tool offset? If you have set tool holders like CAT40, set them before you run the program so the offsets are in the tool table. If you have R8 collets, or a router I am not sure the best way to handle it. Search "touching off after tool change" There are guys with collet system machines that will have to touch off for each change.

yeah, i have collet, so i guess that i mean "setting tool offset" (i am a newbie-- i have had this machine for just a few months and i am "home schooling" myself. the good news is that i have an extensive computer back ground as well as extensive woodworking knowledge (see: www.atelierdebois.com).
i will try your suggestions and get back to you.

jacques

forum.linuxcnc.org/10-advanced-configura...h-off?start=80#89934

it appears that the MTC and touchoff is in this thread, glad I dont have to deal with that!

Simplest thing to do with collet type holders that may get loaded to different heights each time is to break the gcode up into multiple files, one per tool.
Home and touchoff x,y,z for the first program, run it and let it finish. Might be helpfull to have a G0 Z(to suit machine) to move the tool up out of the way.
Load the second tool in the collet, ad the second g-code.
Touch off the z only on a known height (top of part, table, setting block whatever)
Run the second g-code.
Repeat for each tool and associated g-code.

With this method, you don't need to have accurate tool lengths in the tool table.

Not very elegant, but if it is more important to make parts, this will always work

There are more elegant solutions, where you have some sort of switch that you can touch the tool onto at each tool change and set it's length dynamically - search the forum. I now use tool holders that you can preset the length prior to using, so don't have the same issue anymore.

yep, i think i will follow your advice. and yep, while not elegant, it's simple and effective.

can you tell me more about the tool holder that you use? is it an automatic tool changer or something else?

jacques