Jerky motion in Z on Maestro

Veti

have a look at an old post of dc42
https://forum.duet3d.com/topic/1171/testing-the-effects-of-changing-microstepping-and-segmentation

paboman

@veti
thank you!

I understand there is no difference between higher microstepping and interpolated 16x as RRF is quite unique in how it handle the step clalculation. is this right ?

Veti

Using higher resolution microstepping does not increase the physical accuracy of your prints meaningfully, but it can reduce surface artifacts such as moire.
The interpolation is a feature of the TMC driver and not the RRF firmware.
So for the movement the duet is just fine with the accuracy of x16. And the driver internally translates this to x256 stepping for smoother and quieter motion.
If you want more movement accuracy that is where 0.9 degree stepper motors come into play. especially for delta printers.

paboman

Update:
also with 32x Microstepping and interpolation turned on after some hours I get "Hiccups"
now trying 16x microstepping

Veti

@paboman

by "hicups" how many do you mean?

paboman

@Veti
1 hiccup
Enough to ruin the print

Veti

at x32 i would not have expected that.
at what speed are you printing?
do you have an 12864 lcd connected?

paboman

Me too but after few hours 1 hiccup translate into layer shift (in the best scenario)
Printing at 50mm/s non printing moves at 170mm/s
Connected to the Maestro is Panel Due 4,3" and a filament monitor with encoder.

Maybe the reduction ration of the extruder (13:1) also is forcing the cpu to produce a lot of steps as the E0 driver is set to 1166steps/mm (microstepping 16x)

dc42

@paboman said in Jerky motion in Z on Maestro:

@Veti
1 hiccup
Enough to ruin the print

A small number of hiccups should not affect print quality, because each hiccup lasts only 68 microseconds. The step pulse generator pauses for that amount of time to allow the processor to catch up with other tasks. It only does it when the step pulse generator has spent 60 microseconds doing nothing except generating steps.

paboman

the machine was printing, (i was doing M122 every 5 minuts) then I heard a strange noise so looked at the print and it was the beginning of a leyer shift.
After that a M122 get me 1 hiccup

Veti

Alex Kenis found that the drivers work strongest at 24v 1/4 x256 interpolation in stealthchop
https://www.youtube.com/watch?v=GVs2d-TOims&t=1012s

you will need to find the correct value of v for your setup so that it stays in stealthchop even at 170mm/s
M569 Px Vxxx (for each motor)

that is what i would try next

Veti

also from your values. you are using a 40 tooth pulley?
this will actually decrease your positional accuracy compared to the more standard 20 tooth pulley.

edit:forget that. i miscalculated

paboman

Unfortunatelly at 16X interpolated I still get 1 hiccup.
I know @dc42 said it should not affect the print but in my case the 1 hiccup cause a shift in Z resulting into nozzle digging into the print.

Duckle

@paboman Did it sound somewhat like this?
https://www.youtube.com/watch?v=8yGIwlT5qc8

I wasn't aware of the diagnostics output, so I can't say if there were any hiccups, but I'll give it a look if it happens again. The nozzle didn't hit anything, there were no signs of that on the print. I suspected it did on the second snap, but no melted blobs anywhere suggest it did.

Versions:

Firmware Name:          RepRapFirmware for Duet 2 Maestro
Firmware Electronics:	Duet Maestro 1.0
Firmware Version:	2.02RC4(RTOS) (2018-11-18b5)
Web Interface Version:	1.22.5

Specs:

bigDelta custom printer
flying extruder
~750mm print height
400mm print diameter
24v
rattm 17hs8401 1.8deg
- run at 1.3A
- 16x interpolated

Config:

; Configuration file for Duet Maestro (firmware version 1.21)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Sun Oct 07 2018 15:48:41 GMT+0200 (CEST)

; General preferences
G90                             ; Send absolute coordinates...
M83                             ; ...but relative extruder moves
M665 R258.483 L495 B200 H877.95 ; Set delta radius, diagonal rod length, printable radius and homed height 
M666 X-1.66 Y2.69 Z-1.02        ; Put your endstop adjustments here, or let auto calibration find them

; Network
M550 PBigDelta                  ; Set machine name
M551 Pxxx                 ; Set password
M552 P0.0.0.0 S1                ; Enable network and acquire dynamic address via DHCP
M586 P0 S1                      ; Enable HTTP
M586 P1 S1                      ; Enable FTP
M586 P2 S0                      ; Disable Telnet

; Drives
M569 P0 S0                      ; Drive 0 goes forwards
M569 P1 S0                      ; Drive 1 goes forwards
M569 P2 S0 	                ; Drive 2 goes forwards
M569 P3 S1	                ; Drive 3 goes backwards
M92 X100 Y100 Z100 E2567        ; Set steps per mm
M566 X1800 Y1800 Z1800 E1000   	; Set maximum instantaneous speed changes (mm/min)
M203 X18000 Y18000 Z18000 E2500 ; Set maximum speeds (mm/min)
M201 X8000 Y8000 Z8000 E1000     ; Set accelerations (mm/s^2)
M906 X1300 Y1300 Z1300 E500 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30                         ; Set idle timeout
M350 X16 Y16 Z16 E4 I1		; Set microstepping with interpolation
M572 D0 S0.07			; Set 0.07 seconds of pressure advance

; Axis Limits
M208 Z0 S1                      ; Set minimum Z

; Endstops
M574 X2 Y2 Z2 S1                ; Set active high endstops

; Z-Probe
M558 P5 H3 F120 T21000  	; Set Z probe type to switch and the dive height + speeds
G31 P500 X0 Y0 Z30.323	        ; Set Z probe trigger value, offset and trigger height
M557 R200 S20                   ; Define mesh grid

; Heaters
M140 H-1                        ; Disable heated bed
M305 P1 T100000 B4138 C0 R2200  ; Set thermistor + ADC parameters for heater 1
M143 H1 S280                    ; Set temperature limit for heater 1 to 280C

; Fans
M106 P0 S0 I0 F30000 H-1 C"Partfan"	; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F30000 H-1 C"PCBfan"    ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S1 I0 F100 H1 T45 C"Coldfan"  	; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Tools
M563 P0 D0 H1                   ; 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

; Automatic saving after power loss is not enabled

M207 S1.3 F1500 Z0.2 T500  	; Set up firmware retracts

; Miscellaneous
G29 S1				; Load height-map
M501                            ; Load saved parameters from non-volatile memory
T0                              ; Select first tool

paboman

@duckle I stopped the testing, returned the Maestro and installed the Duet Ethernet...no more skipped steps (like the viedo you posted)

Naqaj

Has there been any other resolution to this issue other then "return the maestro and replace with another duet"?

I'm having the exact issue as shown in

@duckle said in Jerky motion in Z on Maestro:

@paboman Did it sound somewhat like this?
https://www.youtube.com/watch?v=8yGIwlT5qc8

and I'm running out of things to troubleshoot that aren't the Maestro.

dc42

@naqaj said in Jerky motion in Z on Maestro:

Has there been any other resolution to this issue other then "return the maestro and replace with another duet"?

I'm having the exact issue as shown in

@duckle said in Jerky motion in Z on Maestro:

@paboman Did it sound somewhat like this?
https://www.youtube.com/watch?v=8yGIwlT5qc8

and I'm running out of things to troubleshoot that aren't the Maestro.

Send m115 to check that you are running 2.02 firmware, not a 2.02RC version.

Naqaj

I could have sworn I already updated to the late december release, but it did indeed say RC06. I'll try again with 2.02, thanks.

paboman

Happy to read that my motion problem was firmware related, I will re-order some Maestro soon!