Homing Issues with CoreXY and two z-axis drivers [SOLVED]

featheryjam2 · 17 Nov 2018, 23:10

Hi, I'm having issues with homing the z axis. It is currently plugged into drivers 2 and 4 and the leadscrews move in sync. I've got a corexy printer (dbot corexy) and am using a precision piezo probe, which seems to work (G30 works great).

The issue I'm having is when I run homez.g (or click the home z button, or run G28 Z). I'm currently running on the 2.02 RC3 (but had the same issues with 2.01, with Duet Wifi). My homez.g is a relatively simple and I've listed it below:

[homez.g]
G28 X
G28 Y
G30

This results in an error "G28 Z Error: Homing Failed", even though each of these commands individually works just fine.

Any thoughts?

Thanks

featheryjam2 · 17 Nov 2018, 23:54

I may have figured it out. Apparently it does not like when you do G28 X or G28 Y in the homez.g script.

mikebridge · 17 Nov 2018, 23:56

here's my homez script for my coreXY w/ 2 Z drivers:

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool on Sat Jan 06 2018 19:43:35 GMT-0600 (Central Standard Time)
G91 ; relative positioning
G1 Z5 F30000 S2 ; lift Z relative to current position
G90 ; absolute positioning
G1 X190 Y206 F30000 ; go to first probe point
G30 ; home Z by probing the bed
; Uncomment the following lines to lift Z after probing
G91 ; relative positioning
G1 Z5 F500 ; lift Z relative to current position
G90 ; absolute positioning

mikebridge · 18 Nov 2018, 02:50

also, in my config.g (I have a duex5 expansion board)
M584 X0 Y1 Z5:6 E3:4 ; Set Drive mappings
M671 X457:-58 Y206:206 S4 ; Define Z-Leadscrew positions

and in my bed.g

G28

G30 P0 X20 Y20 Z-99999
G30 P1 X20 Y345 Z-99999
G30 P2 X370 Y345 Z-99999
G30 P3 X370 Y20 Z-99999
G30 P4 X190 Y206 Z-99999 S2

dc42 · 18 Nov 2018, 07:36

@featheryjam2 said in Homing Issues with CoreXY and two z-axis drivers [SOLVED]:

I may have figured it out. Apparently it does not like when you do G28 X or G28 Y in the homez.g script.

That's correct. You can use M98 Phomex.g and M98 Phomey.g instead if you need to. However, as you are homing Z using a G30 command, you should have the Z endstop position set to "none" in the M574 command, and in that case the firmware will not let you home Z unless X and Y have already been homed.