Home position changes for different starting head positions

cpirius

I've recently upgraded from RRF 2 to 3. I updated my config and it mostly is working, but I'm having problems with the home position. I have a delta printer.

At first I couldn't tell why it wasn't right, it seemed to just change sometimes. Then I realized that the position it thinks is home is changing depending on the position of the print head when it starts the homing process.

For example:
If the print head is all the way at the close to the top when the machine turns on, and I home, I get Z: 365mm (close to the correct value)
But If I turn the machine off, move the head down some distance, maybe 100mm, then turn it on again, then home, I get something like Z440mm
If I do the same and move it more or less, I get different values for z home every time

So there seams to be no way for me to get a consistent home position.

I have a delta printer with a Duet 2 wifi.

I have a z probe configured, but it is not normally attached. Not sure if that is relevant here, I see the same issue weather or not the z probe is attached. It doesn't fit on my print head really so I just use it for calibration then take it off. The top homing has been accurate enough for me to get a consistent z starting height. I have run delta calibration again since upgrading to RRF 3 and it seamed to run correctly.

I've tried v3.1.1 and v3.2 beta4.1, both have the same issue for me.

Thank you for your help!

M98 P"config.g"

Warning: the height map was loaded when the current Z=0 datum was not determined probing. This may result in a height offset.
HTTP is enabled on port 80
FTP is disabled
TELNET is disabled
Warning: Heater 1 appears to be over-powered. If left on at full power, its temperature is predicted to reach 809C
Error: Heater 3 not found
Error: Heater 4 not found
Error: Heater 5 not found
Error: Heater 6 not found
Error: Heater 7 not found

M115

FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 3.1.1 ELECTRONICS: Duet WiFi 1.02 or later FIRMWARE_DATE: 2020-05-19b2

conig.g

; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M555 P1 ; Set firmware compatibility to look like RepRapFirmare
;M555 P2 ; Set firmware compatibility to look like Marlin
G29 S1 ; Load Mesh Bed Compensation Map from SD Card

M911 S19.5 R22 P"G91 M83 G1 Z3 E-5 F1000" ; Setup auto pause on power fail

;*** The homed height is deliberately set too high in the following - you will adjust it during calibration.
M665 R105.11 L225.51 B110 H365 ; Set delta radius, diagonal rod length, printable radius and homed height
M666 X0 Y0 Z0 ; Put your endstop adjustments here, or let auto calibration find them
M208 Z0 S1 ; Set minimum Z

; Endstops
M574 X1 S1 P"xstop"
M574 Y1 S1 P"ystop"
M574 Z1 S1 P"zstop"

; Z-Probe
M558 P5 C"e0stop" F60 T4000 A3 S0.01 ; Set Z probe type to switch, the axes for which it is used and the dive height + speeds, active high
G31 P600 X0 Y0 Z14.805 ; Set Z probe trigger value, offset and trigger height (Position for IR Touch center mount)
;G31 P600 X0 Y0 Z-12.03 ; Set Z probe trigger value, offset and trigger height (Position for micro switch center mount)
;G31 P600 X0 Y0 Z15.765 ; Set Z probe trigger value, offset and trigger height (Position for induction center mount)
;G31 P600 X-24 Y-1 Z4.4 ; Set Z probe trigger value, offset and trigger height (Position for my Chimera print head)

; Calibration
M557 R105 S20 ; Define mesh grid. Radius and Spacing

; Filament Sensor (Using Endstop Input)
M591 P2 C"exp.e2stop" S1 D0

; External Triggers
M950 P1 C"e1stop"
M581 P1 T1 S0 ; Use a falling edge on E0 endstop to trigger a print Pause command

; Drives
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S1 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M92 X160 Y160 Z160 E412 ; Set steps per mm at default 16x microstepping
M350 X16 Y16 Z16 E128 I1 ; Configure microstepping with interpolation
M566 X1200 Y1200 Z1200 E600 ; Set maximum instantaneous speed changes (mm/min)
M203 X30000 Y30000 Z30000 E30000 ; Set maximum speeds (mm/min)
M201 X2000 Y2000 Z2000 E2000 ; Set accelerations (mm/s^2)
M906 X1500 Y1500 Z1500 E800 I45 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Stall Detection
M915 P0 S15 F0 H400 R3 ;On stall detection rehome and restart
M915 P1 S15 F0 H400 R3 ;On stall detection rehome and restart
M915 P2 S15 F0 H400 R3 ;On stall detection rehome and restart

; Temperature Sensors
M308 S0 P"bed_temp" Y"thermistor" T100000 B4725 C7.060000e-8 A"Bed"
M308 S1 P"e0temp" Y"thermistor" T100000 B4725 C7.060000e-8 A"Hot End"
M308 S2 P"e1temp" Y"thermistor" T100000 B4725 C7.060000e-8 A"Air"

; Heater to Temperature Sensor Connection

M950 H0 c"bed_heat" T0
M140 H0
M950 H1 c"e0heat" T1
M950 H2 c"e1heat" T2

; Heater Config

M301 H0 S1.00 P10 I0.1 D200 T0.4 W180 B30 ; Use PID on bed heater (may require further tuning)
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M143 H1 S310 ; Set temperature limit for heater 1 to 310C
;M143 H2 S120 ; Set temperature limit for heater 2 to 120C
M570 S120 ; Configure heater fault detection. Cancel if heating takes longer than time (seconds)

; Tools Z Offset
; More negative z value is farther from the build plate

; Tools
M563 P0 D0 H1 S"Chimera CORE 0.4mm KKIINNGG" ; Define tool 0
G10 P0 X0 Y0 Z-17.6 ; Set tool 0 axis offsets (FlexPlate Magnet with PEI Powder Coated Spring Steel)
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

M563 P1 D0 H1 S"Volcano 1mm" ; Define tool 1
G10 P1 X0 Y0 Z-18.6 ; Set tool 1 axis offsets (FlexPlate Magnet with PEI Powder Coated Steel)
G10 P1 R0 S0 ; Set initial tool 1 active and standby temperatures to 0C

; Network
M550 PATOM2 ; Set machine name
M552 S1 ; Enable network
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet

; Fans
M950 F0 C"fan0"
M950 F1 C"fan1"
M950 F2 C"!fan2" Q500

M106 P0 S0 H-1 c"Part Cooling"
M106 P1 S1 H1 T60 c"Hotend Fan"
M106 P2 C"Enclosure Fan"

; Default tool selection
;T0

M912 P0 S-18 ; CPU Temp Calibration
M501 ; Load overrides

config-override.g

; config-override.g file generated in response to M500 at 2020-08-30 08:17
; This is a system-generated file - do not edit
; Delta parameters
M665 L231.666:231.666:231.666 R106.843 H364.543 B110.0 X-0.116 Y0.475 Z0.000
M666 X0.098 Y0.387 Z-0.485 A0.00 B0.00
; Heater model parameters
M307 H0 A90.0 C700.0 D10.0 S1.00 V0.0 B0
M307 H1 A784.7 C147.2 D1.6 S1.00 V24.0 B0
M307 H2 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H3 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H4 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H5 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H6 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H7 A340.0 C140.0 D5.5 S1.00 V0.0 B0
G10 L2 P1 X0.00 Y0.00 Z0.00
G10 L2 P2 X0.00 Y0.00 Z0.00
G10 L2 P3 X0.00 Y0.00 Z0.00
G10 L2 P4 X0.00 Y0.00 Z0.00
G10 L2 P5 X0.00 Y0.00 Z0.00
G10 L2 P6 X0.00 Y0.00 Z0.00
G10 L2 P7 X0.00 Y0.00 Z0.00
G10 L2 P8 X0.00 Y0.00 Z0.00
G10 L2 P9 X0.00 Y0.00 Z0.00

Phaedrux

@cpirius said in Home position changes for different starting head positions:

; Endstops M574 X1 S1 P"xstop" M574 Y1 S1 P"ystop" M574 Z1 S1 P"zstop"

Your endstops are defined as low end endstops, but the delta homes to the high end. Change X1 Y1 Z1 to X2 Y2 Z2

cpirius

Yep, that fixed it. Thank you!

I must have copied the new format from the example in the config upgrade guide and forgot to change the 1 -> 2's.