Duet 2 wifi z axis takes off on board reset

[cbrunnem2]

I have a cartesian 3d printer. It uses a mech stop on the x and y. A bl touch on the z axis

When the board is reset it now all of a sudden takes off in the z axis away from the printer head. This is new as of yesterday. I don't know where in the configuration files this issue could be as I can't find anything. I also didn't change anything to my knowledge that would cause this.

The printer takes off all the way to the bottom of the z rails then I can only assume stalls until the rest process has finished or power is reset.

Any help would be appreciated. I am at a loss.

[engikeneer]

@cbrunnem2 post you config.g file and the results of M122 so we can see what's going on. Just copy the text into a post using the </> code snippet button so it's easier for us to read

[cbrunnem2]

@engikeneer

; Configuration file for Duet WiFi (firmware version 3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.2.3 on Wed Jul 21 2021 18:08:02 GMT-0400 (Eastern Daylight Time)
 
; General preferences
G90                                           ; send absolute coordinates...
M83                                           ; ...but relative extruder moves
M550 P"My Printer"                            ; set printer name
 
; Network
M552 S1                                       ; enable network
M586 P0 S1                                    ; enable HTTP
M586 P1 S0                                    ; disable FTP
M586 P2 S0                                    ; disable Telnet
 
; Drives
M569 P0 S1                                    ; physical drive 0 goes forwards
M569 P1 S0                                    ; physical drive 1 goes backwards
M569 P2 S1                                    ; physical drive 2 goes forwards
M569 P3 S1                                    ; physical drive 3 goes forwards
M584 X0 Y1 Z2 E3                              ; set drive mapping
M350 X256 Y256 Z256 E256 I0                   ; configure microstepping without interpolation
M92 X1280.00 Y1280.00 Z6400.00 E1563      ; set steps per mm
M566 X600 Y600 Z300 E120         ; set maximum instantaneous speed changes (mm/min)
M203 X12000.00 Y12000.00 Z3600 E4800.00    ; set maximum speeds (mm/min)
M201 X400 Y400 Z100 E250          ; set accelerations (mm/s^2)
M906 X800 Y800 Z800 E800 I50                  ; set motor currents (mA) and motor idle factor in per cent
M84 S50                                       ; Set idle timeout
 
; Axis Limits
M208 X0 Y0 Z-2.0 S1                              ; set axis minima
M208 X350 Y400 Z400 S0                        ; set axis maxima
 
; Endstops
M574 X1 S1 P"xstop"                           ; configure active-high endstop for low end on X via pin xstop
M574 Y1 S1 P"ystop"                           ; configure active-high endstop for low end on Y via pin ystop
M574 Z1 S2                                    ; configure Z-probe endstop for low end on Z
 
; Z-Probe
M950 S0 C"exp.heater3"                        ; create servo pin 0 for BLTouch
M558 P9 C"^zprobe.in" H5 F600 T6000           ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X0 Y0 Z1.94                    ; set Z probe trigger value, offset and trigger height Z1.92 for .8mm nozzle 1.84 for .8mm nozzle
M557 X50:350 Y0:400 S100                      ; define mesh grid
 
; Heaters
M140 H-1                                      ; disable heated bed (overrides default heater mapping)
M308 S0 P"e0temp" Y"thermistor" T100000 B4138 ; configure sensor 0 as thermistor on pin e0temp
M950 H0 C"e0heat" T0                          ; create nozzle heater output on e0heat and map it to sensor 0
M307 H0 B0 S1.00                              ; disable bang-bang mode for heater  and set PWM limit
M143 H0 S300                                  ; set temperature limit for heater 0 to 300C
 
; Fans
M950 F0 C"fan0" Q500                          ; create fan 0 on pin fan0 and set its frequency
M106 P0 S1 H-1                                ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"fan1" Q500                          ; create fan 1 on pin fan1 and set its frequency
M106 P1 S1 H-1                                ; set fan 1 value. Thermostatic control is turned off
 
; Tools
M563 P0 D0 H0 F0                              ; define tool 0
G10 P0 X0 Y0 Z0                               ; set tool 0 axis offsets
G10 P0 R0 S0                                  ; set initial tool 0 active and standby temperatures to 0C
 
; Custom settings are not defined
 

M122
=== Diagnostics ===
RepRapFirmware for Duet 2 WiFi/Ethernet version 3.1.1 running on Duet WiFi 1.02 or later
Board ID: 0JD0M-9P6B2-NJ4S8-6J9F6-3SJ6L-1A4QK
Used output buffers: 3 of 24 (13 max)
=== RTOS ===
Static ram: 27980
Dynamic ram: 93632 of which 20 recycled
Exception stack ram used: 600
Never used ram: 8840
Tasks: NETWORK(ready,268) HEAT(blocked,1224) MAIN(running,1732) IDLE(ready,80)
Owned mutexes: WiFi(NETWORK)
=== Platform ===
Last reset 06:19:07 ago, cause: software
Last software reset at 2021-09-02 07:48, reason: User, spinning module GCodes, available RAM 8792 bytes (slot 0)
Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0441f000 BFAR 0xe000ed38 SP 0xffffffff Task MAIN
Error status: 0
MCU temperature: min 32.6, current 35.9, max 39.5
Supply voltage: min 23.7, current 24.1, max 24.6, under voltage events: 0, over voltage events: 0, power good: yes
Driver 0: standstill, SG min/max 0/257
Driver 1: standstill, SG min/max 0/245
Driver 2: standstill, SG min/max 0/613
Driver 3: standstill, SG min/max 0/119
Driver 4: standstill, SG min/max not available
Date/time: 2021-09-02 14:07:57
Cache data hit count 4294967295
Slowest loop: 203.84ms; fastest: 0.12ms
I2C nak errors 0, send timeouts 0, receive timeouts 0, finishTimeouts 0, resets 0
=== Storage ===
Free file entries: 10
SD card 0 detected, interface speed: 20.0MBytes/sec
SD card longest read time 5.2ms, write time 53.0ms, max retries 0
=== Move ===
Hiccups: 17795(0), FreeDm: 169, MinFreeDm: 116, MaxWait: 148682ms
Bed compensation in use: mesh, comp offset 0.000
=== MainDDARing ===
Scheduled moves: 255722, completed moves: 255722, StepErrors: 0, LaErrors: 0, Underruns: 0, 0  CDDA state: -1
=== AuxDDARing ===
Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0  CDDA state: -1
=== Heat ===
Bed heaters = -1 -1 -1 -1, chamberHeaters = -1 -1 -1 -1
Heater 0 is on, I-accum = 0.4
=== GCodes ===
Segments left: 0
Movement lock held by null
HTTP is idle in state(s) 0
Telnet is idle in state(s) 0
File is idle in state(s) 0
USB is idle in state(s) 0
Aux is idle in state(s) 0
Trigger is idle in state(s) 0
Queue is idle in state(s) 0
Daemon is idle in state(s) 0
Autopause is idle in state(s) 0
Code queue is empty.
=== Network ===
Slowest loop: 111.82ms; fastest: 0.00ms
Responder states: HTTP(2) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0), 0 sessions
HTTP sessions: 1 of 8
- WiFi -
Network state is active
WiFi module is connected to access point 
Failed messages: pending 0, notready 0, noresp 0
WiFi firmware version 1.23
WiFi MAC address EDITED
WiFi Vcc 3.38, reset reason Unknown
WiFi flash size 4194304, free heap 22608
WiFi IP address EDITED
WiFi signal strength -52dBm, reconnections 0, sleep mode modem
Socket states: 0 0 0 0 0 0 0 0

[Phaedrux]

So the instant you power on the Z axis starts to move?

@cbrunnem2 said in Duet 2 wifi z axis takes off on board reset:

Hiccups: 17795(0)

M350 X256 Y256 Z256 E256 I0 ; configure microstepping without interpolation
M92 X1280.00 Y1280.00 Z6400.00 E1563 ; set steps per mm

It's not recommended to use x256 microstepping for all axis as it can overwhelm the step generation and provides no real benefit. x16 with interpolation enabled is generally the way to go. I suggest switching to that and adjusting your steps per mm accordingly.

@cbrunnem2 said in Duet 2 wifi z axis takes off on board reset:

Duet 2 WiFi/Ethernet version 3.1.1

Probably also a good idea to update your firmware to 3.3

Upload this zip file to the system tab in DWC.

https://github.com/Duet3D/RepRapFirmware/releases/download/3.3/Duet2and3Firmware-3.3.zip

With those changes in place, see if it still behaves the same.

[cbrunnem2]

@phaedrux

1. I don't know if it moves on power up as it already is bottomed out so it can't move any further down. It moves down at a reset of any type.
2. I will change the microstepping. Do you recommend on all axis or just z?
3. I will update the firmware.

[Phaedrux]

Use x16 with interpolation for all axis. The only time using higher makes any sense is if you need extra resolution in an extruder that has a very low natural steps per mm like an ungeared direct drive extruder with a 1.8 motor.

Are you able to manually move the Z axis up even when it's bottomed out?

Does it sound like the motors are stalling?

What kind of a Z axis is it? Does it have enough weight to fall on it's own? You say it's a cartesian, but is it a bed that moves in Y or does the bed move in Z?

[cbrunnem2]

@phaedrux x and y move on a trolley rail system. Z moves strictly up and down. It has a lead screw on two sides of the bed and uses two motors. One on each lead screw.

As mentioned, the only time this happens is when the board is reset. Once it reboots I have to rehome and level the bed. I can then print as normal.

Lastly, my extruder is a non geared with a 200 step per rev stepper so it sounds like it's a good idea to not use 16x? Recommendation?

[Phaedrux]

It sounds like the Z axis is heavy enough that it could be causing it to auto rotate and fall when the motors are de-energized.

Photos?

@cbrunnem2 said in Duet 2 wifi z axis takes off on board reset:

my extruder is a non geared with a 200 step per rev stepper so it sounds like it's a good idea to not use 16x? Recommendation?

Adjust your microstepping so that your steps per mm are in the 400 range.

[cbrunnem2]

@phaedrux I'll send pictures later. It's definitely driving as the couplers attaching the screw to the motor stretch out when it bottoms out.

Will make the adjustments and report back.

[cbrunnem2]

just installed the new firmware. as soon as it asked me if i wanted to install and i clicked yes, the bed took off downward.

after i reset the microsteps... issue gone.

i have had x256 working for over a month. why is this an issue now?

[cbrunnem2]

Soooo I just realized that I greased the z lead screws since the last reset. It's likely falling. Never thought it could fall this fast. Any way to prevent this?

Def need to find a way to tie the two z lead screws together. Can't find a belt that can span 20 inches. Might have to come up with a contraption to use 2 belts.

[Phaedrux]

Using a lead screw with a shallower pitch could help. Or perhaps adding spring loaded anti-backlash nuts to increase the friction.

If you have a spare driver you can use one for each Z motor and then use auto leveling to get them in sync and level with the bed.

https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors

[fcwilt]

@cbrunnem2

Well as you may have observed in the past after a re-boot the steppers are off so your Z axis can fall due to your 8mm lead lead screws.

What you could try is putting a G91 G1 Z0.1 pair of commands in your config file, after the steppers are configured, to turn the Z steppers on.

Now normally doing a move in your config file is considered a bad idea but a tiny move would likely be ok.

Frederick

[cbrunnem2]

@phaedrux hmm this could be the ticket here.

yall are awesome. just needed some good nudging to get to the right path. also fixed some things too that i didnt know needed fixed!