Taz 6 - How do I change Global Coordinate System and G29 script ?

Hi all,

I need to print something that is quite long and will not fit on the square bed. In order to print my part, I have decided to lengthen the Y printable area. The lengthened rods and frame have already been installed but I don’t know how to change the Y location after the end stop is hit during homing. Does anyone know how increase this value so after homing Y, the printer thinks its at a larger Y location ? Also, does anyone know how to change the G29 script so that the tool head will Z probe the 4 washers at their new Y shifted location ?

Here is a picture of my current setup. I have not purchased the lengthened glass yet. The second picture shows what the lengthened glass would look like.

Thank you all for your time !

You will need to recompile the firmware, after changing the affected variables in configuration.h:

// Travel limits after homing
#define X_MAX_POS 300
#define X_MIN_POS -20
#define Y_MAX_POS 303
#define Y_MIN_POS -20
#define Z_MAX_POS 270
#define Z_MIN_POS 00

The Probing locations are also in that file:

// set the rectangle in which to probe
    #define LEFT_PROBE_BED_POSITION -9
    #define RIGHT_PROBE_BED_POSITION 288
    #define BACK_PROBE_BED_POSITION 289
    #define FRONT_PROBE_BED_POSITION -9

I think you will need to change the Y point here, too:

    #define Z_SAFE_HOMING_X_POINT (-19)    // X point for Z homing when homing all axis (G28)
    #define Z_SAFE_HOMING_Y_POINT (258)    // Y point for Z homing when homing all axis (G28)

That same Y point will need to go into all you startup scripts for homing:

G28 XY                       ; home X and Y
G1 X-19 Y258 F1000           ; move to safe homing position
M109 R170                    ; soften filament for z homing
G28 Z

And of course you’ll have to change the Y coordinates for the wiping sequence in your startup scripts, too.

That should get you started… I can’t guarantee I thought of everything above, so proceed carefully! :slight_smile:

Hi Scott,

Thank you for the very detailed reply ! I have no experience with 3d printer firmwares and have taken the last few days to do some research. I think I understand the process now and was wondering where I might be able to find the TAZ 6 preconfigured firmware package. Lulzbot’s website only has the compiled .hex file so I am not sure where to start.

Thanks for your time !
David

Hi David,

Glad to help. There is a compressed tar archive (.tar.gz file) of all the source files here:
http://download.lulzbot.com/TAZ/6.01/software/firmware/

You’ll also need the Arduino IDE. You can get that here:
https://www.arduino.cc/en/main/software