Homing to back of printer is not working

war4peace

Hi all, it's me again, apologies for the second topic today...
Working on configuring my RatRig V-Core 3, I have X and Y endstops, where X endstop is at the X min (left side of the carriage) and the Y endstop is at the back of the printer (Y max).

So what I would like to achieve is:

Homing X: carriage moves to the left towards the endstop until it hits it and triggers (this is working);
Homing Y: carriage moves to the back of the printer towards the endstop until it hits it and triggers (this is where the issue is).

I have read the M574 section multiple times to no avail (https://duet3d.dozuki.com/Wiki/Gcode#Section_M574_Set_endstop_configuration).

The config.g commands are below:

; Endstops
M574 X1 S1 P"io1.in"                           ; configure active high endstops at minX
M574 Y2 S1 P"io2.in"                           ; configure active high endstops at maxY
M574 Z1 S2                                     ; configure Z-probe endstop for low end on Z

Homey.g below:

G91               ; relative positioning
;G1 H2 Z5 F6000    ; lift Z relative to current position
G1 H1 Y505 F1800 ; move quickly to Y axis endstop and stop there (first pass)
G1 Y-5 F6000     ; go back a few mm
G1 H1 Y505 F360  ; move slowly to Y axis endstop once more (second pass)
;G1 H2 Z-5 F6000   ; lower Z again
G90               ; absolute positioning

G1 Y250 F6000

I tested the endstops by pressing them manually and the carriage stops when I press them, meaning they are configured correctly and work.
When I Home Y, the carriage always moves forward (towards Y=0) instead of towards the back of the printer (Y=505). Of course, no endstop is there.

How should I configure my printer to go towards the back of the printer when homing Y?

Thank you once more for your help!

MGJosh

@war4peace
I'd say first check that your Y gantry is moving the correct direction - if you hit the Y endstop while Y is homing, then command a 10mm move, you can tell which direction the firmware thinks the gantry should be moving. As you've got a CoreXY I imagine the configuration is a bit more complicated than on the Cartesians I'm used to, but https://duet3d.dozuki.com/Wiki/Gcode#Section_M667_Select_CoreXY_or_related_mode and https://duet3d.dozuki.com/Wiki/Gcode#Section_M569_Set_motor_driver_direction_enable_polarity_and_step_pulse_timing should be enough to figure out how to get the motor logic switched around.

Because this is CoreXY I don't actually have a strong intuition for how the motors all work together, so I'm not even sure if a single motor moving the wrong direction can flip just the Y gantry movement...

Separately (but maybe related?) - is there a reason you used "io2.in" for your Y endstop, instead of the "io0.in" from the build instructions?

Finally, in the likely case my reply didn't help much - can you post your full config.g file for anyone else to check?

war4peace

@mgjosh said in Homing to back of printer is not working:

Separately (but maybe related?) - is there a reason you used "io2.in" for your Y endstop, instead of the "io0.in" from the build instructions?

Finally, in the likely case my reply didn't help much - can you post your full config.g file for anyone else to check?

To answer the first question, I also have a PanelDue 5i and the documentation said it must be connected to io_0 to work.
https://duet3d.dozuki.com/Wiki/Connecting_an_LCD_control_panel#Section_Duet_Num_3

As for the config.g, I have modified it several times since I posted, it would be useless to upload it now. It's past midnight here, will attempt some more troubleshooting tomorrow morning and post updates, together with the config.g file.

Thank you for yourr eply, I appreciate it!

Phaedrux

Your config and homing file looks correct.

The problem is either with the direction of rotation of one of your motors or the motors themselves might need to be swapped at the plug. Don't alter your config or homing file.

Do the tests here and adjust accordingly.

https://duet3d.dozuki.com/Wiki/ConfiguringRepRapFirmwareCoreXYPrinter#Section_Testing_motor_movement

war4peace

@phaedrux Hi, thank you, yes, it was indeed stepper wiring, and it's now resolved.
Thank you!