Marlin M218 Extruder Offset.Documented as only X / Y but the code says also Z?

[neotko 1,356]

Hi,

Another question for Marlin experts.

I was wondering how to change the Z offset by firmware for my dual extruder bla bla bla.

After googling and reading everywhere, Marlin on Ultimaker offset adjustment only says X & Y as posible adjustments. But after opening the Marlin_main.cpp to check what the M218 code actually does and as far as I can read-code it seems to be ready to use Z offset changes.

 

#if EXTRUDERS > 1   case 218: // M218 - set hotend offset (in mm), T X Y   {     if(setTargetedHotend(21){       break;     }     if(code_seen('X'))     {       extruder_offset[X_AXIS][tmp_extruder] = code_value();     }     if(code_seen('Y'))     {       extruder_offset[Y_AXIS][tmp_extruder] = code_value();     }     #ifdef DUAL_X_CARRIAGE     if(code_seen('Z'))     {       extruder_offset[Z_AXIS][tmp_extruder] = code_value();     }     #endif

 

Does that really means that I could do a M218 T1 Z0.3 (for example) and it should work? I mean, if only 'kick in' if there's DUAL_X_CARRIAGE, but I assume that if I kill that 'if' check, it should just allow it, or there will be more dual_x_carriage checks for this to kickin?

Edited May 26, 2015 by Guest

[pbrgle1 0]

Hey. I was just wondering the same thing. I just built a dual x carrige printer and the heads have 0.5mm height difference. Did you figure it out?

[neotko 1,356]

No I didn't. For now until a more advancedfirmware/software it's out I just use simplify3d to set the z offset of the second extruder (or the first depends on who it's lower than the other to avoid the problem of the z stop).

[pbrgle1 0]

And how do you do that? I can only see X and Y tool offsets

[neotko 1,356]

Z? on this panel

[neotko 1,356]

I change g code offset for each extruder processes, and level the bed to the higher extruder. Ofc on my system I have 2mm margin of error on the parking system and that helps, but it's good enough to avoid crash on the bed. For extruder 0 offset 0 and for extruder 1 I set a 0.8 offset, the bed lowers when it changes. Bless the software =)

[nicksears 1]

Anyone get anywhere on this? I wish slic3r had this option, but for now I'm trying firmware implementation. When I comment out the ifs it seems to work (compiles/uploads fine) and when I send M218 T0 Xxxx Yyyy Zzzz (works fine), but when I send M218 T1 Xxxx Yyyy Zzzz (or even just M218 T0 Xxxx Yyyy) it freezes. I'm thinking there are other areas that have if statements that expect dual_x_carriage to be defined, and are therefor not working...

NEVERMIND I GOT IT! You just have to comment out another if here:

// Extruder offsets

#if EXTRUDERS > 1

#ifndef EXTRUDER_OFFSET_X

#define EXTRUDER_OFFSET_X { 0 }

#endif

#ifndef EXTRUDER_OFFSET_Y

#define EXTRUDER_OFFSET_Y { 0 }

#endif

float extruder_offset[][EXTRUDERS] = {

EXTRUDER_OFFSET_X,

EXTRUDER_OFFSET_Y

//#if ENABLED(DUAL_X_CARRIAGE)

, { 0 } // supports offsets in XYZ plane

//#endif

};

#endif

and the original, both in marlin_main:

#if EXTRUDERS > 1

/**

* M218 - set hotend offset (in mm), T X Y

*/

inline void gcode_M218() {

if (setTargetedHotend(218)) return;

if (code_seen('X')) extruder_offset[X_AXIS][target_extruder] = code_value();

if (code_seen('Y')) extruder_offset[Y_AXIS][target_extruder] = code_value();

//#if ENABLED(DUAL_X_CARRIAGE)

if (code_seen('Z')) extruder_offset[Z_AXIS][target_extruder] = code_value();

//#endif

SERIAL_ECHO_START;

SERIAL_ECHOPGM(MSG_HOTEND_OFFSET);

for (int e = 0; e < EXTRUDERS; e++) {

SERIAL_CHAR(' ');

SERIAL_ECHO(extruder_offset[X_AXIS][e]);

SERIAL_CHAR(',');

SERIAL_ECHO(extruder_offset[Y_AXIS][e]);

//#if ENABLED(DUAL_X_CARRIAGE)

SERIAL_CHAR(',');

SERIAL_ECHO(extruder_offset[Z_AXIS][e]);

//#endif

}

SERIAL_EOL;

}

#endif // EXTRUDERS > 1

Edited June 15, 2016 by Guest
solved!

[neotko 1,356]

Nice one!

[drayson 62]

ok, another year went by and there is another guy like to use the z offset... :-)

So IF I set all a.m. modifications

AND define a new variable EXTRUDER_OFFSET_Z in configuration.h in the area of offset definition

 

// Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).// The offset has to be X=0, Y=0, Z=0 for the extruder 0 hotend (default extruder, T0).// For the other hotends it is their distance from the extruder 0 hotend.// #define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis// #define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis#define EXTRUDER_OFFSET_Z {0.0, 1.00}  // (in mm) for each extruder, offset of the hotend on the Z axis

 

AND put it in the correct area of marlin_main.ccp (incl. commenting out the dual stuff),

 

// Extruder offset#if EXTRUDERS > 1//#ifndef DUAL_X_CARRIAGE//  #define NUM_EXTRUDER_OFFSETS 2 // only in XY plane//#else #define NUM_EXTRUDER_OFFSETS 3 // supports offsets in XYZ plane//#endiffloat extruder_offset[NUM_EXTRUDER_OFFSETS][EXTRUDERS] = {#if defined(EXTRUDER_OFFSET_X) && defined(EXTRUDER_OFFSET_Y) && defined(EXTRUDER_OFFSET_Z) EXTRUDER_OFFSET_X, EXTRUDER_OFFSET_Y, EXTRUDER_OFFSET_Z#endif};#endif

 

it should be possible to define the z offset during compilation and no need for M218 - isn't??

Well, I'm using a Marlin version of 2014, so it might look a bit different now.

(but my UMO runs fine on it... so why change a running system) :-)

Edited October 24, 2017 by Guest