Posts made by Zerbob

Tried both and got the same result. It seems that the printer is resetting its height before a dive, causing it to dive too short. If you obstruct the probe early with your finger, it works as intended. However left to itself, it will not lower enough for the probe to even reach the bed.

I've run it at 250 and 500 before, but I will try a little higher and see if that helps. Won't be able to test till tomorrow. Thank you for still checking in.

I have turned the Z acceleration down quite a bit, from 250mm/s^2 to 100mm/s^2. I also changed homez.gcode to utilize the endstop. With the new homez.gcode I get very consistent zeroing.

To test the probing I do the following set of commands.

M558 P9 F200 T9000 H5 A3     ; set probe type to BLTouch, feed rate to 200mm/min, travel between points to 9000 mm/min, dive height 3mm, probe three times

G1 X0 Y0 F9000     ; go to x0 y0
G28 Z                     ; home the Z axis
G1 Z4.5 F200          ; move 
G30                         ; perform single point probe

This code should cause the Z axis to be correctly home, then probe the same spot three more times. The result is similar to before. The homing probe will be performed correctly (it is using a G1 S1 Z-1300 F200, followed by a G92). I then make sure that the probe is within the dive height to the bed based off the measurement just performed. The probing move is then started but the probe will stop a mm or two short of the bed then state "Error: Z probe was not triggered during probing move".

On the probing move it is visibly not descending far enough before stopping and reporting the error. No heaters or fans are running during any of these tests.

It is a moving gantry. Our bed weighs about 110kg and consists of a metal sheet on a galvanized steel pallet. Moving the bed was not feasible.

The Z axis consists of 2 threaded rods but the motion itself is on precision linear rails.

I'll try turning the Z acceleration down and report back with the results tomorrow.

I'd be very surprised if it was skipping steps. The Z axis is driven by two Nema 23's on an external high power driver (DM860AC). We have run the Z axis on big moves vertically and it does them correctly at 300 mm/min. We have run the motors to the point where they start to skip and do not see/hear skipping steps. We have run the Z axis up to 500 mm/min but slowed them down due to vibrations.

It will also probe correctly on the first attempt. Even if we set M558 A >1 it will probe it once correctly, then fail to probe close to the same distance on the second attempt. This can be seen in the linked video above.

Thank you.

Do you have any thoughts to the issue above relating to probing? It's a very odd situation and I have been unable to find others with the same issue even.

Is there a way to trigger that macro to run on boot?

Could you actually provide a more detailed example of M589? I tried doing that but kept getting an error stating incorrect parameters.

I'll give that a try tomorrow. It is running as part of a bundle of wires which contains multiple steppers, a heating element, and a fan. The steppers and heater are in shielded wire, but the lengths are long enough we could even get interference from fluorescent lights (which I've experienced with telephone wires).

Maybe I'll try a small capacitor and playing with the trigger value. We have been testing with the heaters off for now.

What confuses me is that M401 and M402 both work. G28 Z works. But when we go to G29 it doesn't behave correctly. We even noticed this when we swapped the BLTouch for an inductive sensor I had on hand.

I'll also be sure to put the build up on the forum. We're focused on finishing the project right now, but afterwards will be hitting up some of the various 3D printer sites and communities.

Tried changing the Z trigger height to positive. Might have been a mistake. It did not solve the issue.

For the Z axis we are using M12 threaded rods. Our gantry is about 1.5mx1.5m and is carrying about 10kg of weight. We can't go much faster or else we get vibration build up. The Z axis is about 2m tall. Future work is to upgrade them to lead screws but we were limited by cost and lead time.

I've tried your settings but still get this weird behaviour. Video: https://drive.google.com/file/d/1pSdNuHWDPTvjjOFv8BxW1zxDio94YLGC/view?usp=sharing

I have tried to get the Duet direct method working, but must be doing the code wrong. With our deadline looming it was shelved for later. We're not using home all at the moment as what we're printing is a lot smaller than our total build volume (plus we haven't wired the X & Y endstops yet).

[[language]]
; Configuration file for Duet WiFi (firmware version 1.20 or newer)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Sat Mar 31 2018 08:48:41 GMT-0400 (Eastern Daylight Time)

; General preferences
G90                                     ; Send absolute coordinates...
M83                                     ; ...but relative extruder moves
M555 P1                                 ; Set firmware compatibility to look like RepRapFirmare

; Network

; Drives
M569 P0 S1                              ; Drive 0 goes forwards
M569 P1 S1                              ; Drive 1 goes forwards
M569 P2 S1                              ; Drive 2 goes forwards
M569 P3 S0                             ; Drive 3 goes forwards
M569 P5 S1 R0 T2.5:2.5:5:0				;Settings for external Z driver
M584 X0 Y1 Z5 E3                        ; Apply custom drive mapping
M350 X16 Y16 Z16 E16 I1                 ; Configure microstepping with interpolation
M92 X100 Y100 Z3909.340 E645             ; Set steps per mm
M566 X1800 Y1800 Z30 E120               ; Set maximum instantaneous speed changes (mm/min)
M203 X30000 Y30000 Z300 E6000           ; Set maximum speeds (mm/min)
M201 X4500 Y4500 Z250 E250              ; Set accelerations (mm/s^2)
M906 X800 Y2000 Z100 E800 I30           ; Set motor currents (mA) and motor idle factor in per cent
M84 S30                                 ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z0 S1                        ; Set axis minima
M208 X1400 Y1400 Z1800 S0               ; Set axis maxima

; Endstops
;M574 X1 Y2 S3                           ; Set endstops controlled by motor load detection
M574 X0 Y0
;M915 X Y S5 R0							; Set motor drivers for stall detection

; Z-Probe
M307 H3 A-1 C-1 D-1						; Disable Heater 3 to be used for probe
M307 H2 A-1 C-1 D-1
M574 Z1 S2                              ; Set endstops controlled by probe
M558 P9 H20 F300 T6000                   ; Set Z probe type to switch and the dive height + speeds
G31 P250 X0 Y0 Z-0.15                     ; Set Z probe trigger value, offset and trigger height
M557 X0:1000 Y0:1000 S100               ; Define mesh grid

; Heaters
M305 P0 X100          ; Set thermistor + ADC parameters for heater 0
M143 H0 S100                            ; Set temperature limit for heater 0 to 100C
M305 P1 T98640 B4633 C9.486166e-8 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S280                            ; Set temperature limit for heater 1 to 280C

; Fans
M106 P0 S1 I0 F500 H1 T45               ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P1 S1 I0 F500 H-1                  ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S1 I0 F500 H-1                  ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off

; Tools
M563 P0 D0 H1                           ; Define tool 0
G10 P0 X22.5 Y-24 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

; Custom settings are not configured

[[language]]
; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool on Sat Mar 31 2018 08:48:41 GMT-0400 (Eastern Daylight Time)
;G91                ; relative positioning
;G1 Z5 F6000 S2     ; lift Z relative to current position
;G90;
G1 X0 Y0 F9000;
G30
;G1 S1 Z-1805 F1800 ; move Z down until the switch triggers
;G92 Z0.2           ; set Z position to trigger height

; Uncomment the following lines to lift Z after probing
;G91               ; relative positioning
G1 Z5 F100 S2     ; lift Z relative to current position
;G90               ; absolute positioning

Hello Duet3D Forum

We're a student group working on a large 3D printer as part of an engineering capstone project. We've got just about everything working, but we're encountering an odd behavior with a BLTouch on a Duet WiFi. We are currently controlling the printer via USB and Printrun as we can't connect the Duet via the school WiFi (it requires a log in).

We have a BLTouch connected to the Heater 3 pin of the expansion port, and the ZProbe pins.

The probe works correctly with a G28 Z move. However on a G29 we get some oddness. It will probe the first point correctly, however when it moves to the second point the probe will only descend about halfway, then a "Z probe not triggered on probing move" error is reported. An image is shown below to illustrate: