BLTouch Probe Won't Deploy

Charlie

@fcwilt
Okay, that explains why the M280 command worked even though I messed up the P value.

With that said, Im still having issues deploying the BLTouch probe when homing the Z axis. The M280 P0 S10 and M401 commands successfully deploy the probe.

JoergS5

@charlie one issue in your config.g is, that the speeds are very low:

M203 S1 X300.00 Y300.00 Z15.00 E20.00

S1 does not exist for M203, so the speeds are mm/min, so e.g. Z is only 0.25 mm/s. So your probing might run into a timeout. Please use higher values. I would take the values of the documentation of M203: https://duet3d.dozuki.com/Wiki/M203

BUT: does Voron has a specific firmware, where S1 is valid? Then the firmware could be a reason for your problem, but I don't know how to help then. Which tool did you use to create the config file? Marlin and Slic3rPR use mm/s, but RRF use mm/min.

Charlie

@joergs5
I assumed based on Duet3D Changelog: RepRapFirmware 3.3

"The M203 command now supports an optional S1 parameter which changes the units to mm/sec. The default is still mm/min."

The X, Y, and Z homing speeds appear to be the same speed as I had before the change to S1. The probe just doesnt deploy during the Z homing step.

JoergS5

@charlie then sorry, it is not in the documentation yet.

I proceed searching for a possible reason...

JoergS5

@charlie homing is often made by homeall.g, can you please post it, and homex.g and homey.g also?

How do you home Z: individually X, Y, Z or together in one step?

fcwilt

@charlie said in BLTouch Probe Won't Deploy:

The X, Y, and Z homing speeds appear to be the same speed as I had before the change to S1. The probe just doesnt deploy during the Z homing step.

There are parameters to M558 to control probing speeds (travel and probing) including the ability to specify two probing speeds.

As another poster has mentioned you didn't post homeall.g which may well be why we didn't spot the problem.

Frederick

Charlie

@joergs5

No worries. I greatly appreciate your willingness to help!

In this case, I am homing X, then Y, then Z. With that said, the issue also occurs using the "Home All" button in DWC.

fcwilt

@charlie said in BLTouch Probe Won't Deploy:

@joergs5

No worries. I greatly appreciate your willingness to help!

In this case, I am homing X, then Y, then Z. With that said, the issue also occurs using the "Home All" button in DWC.

So homing just Z with the DWC Home Z button does not work? Just want to be sure I understand what is happening.

Frederick

Charlie

@joergs5

homex.g

; Voron.
; 0:/sys/homex.g
; Called to home the X axis via G28 X.
; 2020/10/24/20:00

G91               ; Set axes (not extruders) to relative positioning mode.
G1 H2 Z5 F6000    ; Lift Z relative to current position.
G1 H1 X355 F6000  ; Move quickly to X endstop (1 of 2 passes).
G1 H0 X-3 F6000   ; Move away from X endstop.
G1 H1 X10 F360    ; Move slowly to X axis endstop once more (2 of 2 passes).
G1 H2 Z-5 F6000   ; Lower Z relative to current position.
G90               ; Set axes (not extruders) to absolute positioning mode.

homey.g

; Voron
; 0:/sys/homey.g
; Called to home the Y axis via G28 Y.
; 2020/10/24/20:01

G91               ; Set axes (not extruders) to relative positioning mode.
G1 H2 Z5 F6000    ; Lift Z relative to current position.
G1 H1 Y360 F6000  ; Move quickly to Y endstop (1 of 2 passes).
G1 H0 Y-3 F6000   ; Move away from Y endstop.
G1 H1 Y10 F360    ; Move slowly to X axis endstop once more (2 of 2 passes).
G1 H2 Z-5 F6000   ; Lower Z relative to current position.
G90               ; Set axes (not extruders) to absolute positioning mode.

homeall.g

; Voron.
; 0:/sys/homeall.g
; Called to home all axes via G28.
; 2020/10/24/21:00

G91                    ; Set axes (not extruders) to relative positioning mode.
G1 H2 Z5 F6000         ; Lift Z relative to current position.
G1 H1 X355 Y360 F6000  ; Move quickly to X or Y axis endstop and stop there.
G1 H1 X355 F6000       ; Move quickly to X endstop and stop there.
G1 H1 Y360 F6000       ; Move quickly to Y endstop and stop there.
G1 H0 X-3 Y-3 F6000    ; Move away from X and Y endstops.
G1 H1 X10 F360         ; Move slowly to X endstop once more.
G1 H1 Y10 F360         ; Move slowly to Y endstop once more.
G90                    ; Set axes (not extruders) to absolute positioning mode.
G1 X175 Y151.5 F6000   ; Move X and Y axes so the Z probe is at the center of the bed.
M558 F600 H2 A1        ; Set Z probe. Feed rate: 600 mm/min. Dive height: 2 mm. Times to probe: 1.
G30                    ; Z probe quickly (1 of 2 passes).
M558 F120 H5 A1        ; Set Z probe. Feed rate: 120 mm/min. Dive height: 5 mm. Times to probe: 1.
G30                    ; Home Z by probing the bed slowly (2 of 2 passes).

JoergS5

@charlie you may need to exchange the order or M950 and M558:

in the M950 documentation https://duet3d.dozuki.com/Wiki/M950 :
"M950 must come before any commands that refer to the device being created."
So M950, then M558 which uses the servo part of BLTouch.

I am not sure about this. In the examples I know, M950 is first, M558 next, but the two commands don't have a reference to each other. But it's worth a try. M558 may expect to know the M950 values.

Charlie

@fcwilt
That is correct. Homing just Z doesnt work.

It also doesnt work if I use "Home All".

fcwilt

@charlie said in BLTouch Probe Won't Deploy:

@fcwilt
That is correct. Homing just Z doesnt work.

It also doesnt work if I use "Home All".

OK let's take the homing code out of the picture.

Can you reset the printer and successfully home X and Y?

Frederick

JoergS5

@charlie a last additional idea: M208 has Z minimum 0 and the BLTouch starts at 3 mm height. It may be that it cannot probe below 0 because of M208. This was changed in 3.4 somewhere if I remember correct, but if you use 3.3 firmware, it may be a try to set the M208 Z limit below 0.

Charlie

@fcwilt
Im assuming that "reset" means sending an M999 command, or powering off the duet. In that case, X and Y works wonderfully when I home them individually. Furthermore, the X and Y portions of the Home All function work as intended as well.

Charlie

@joergs5
Unfortunately, this did not fix the issue. I appreciate the attempt though!

fcwilt

@charlie said in BLTouch Probe Won't Deploy:

@fcwilt
Im assuming that "reset" means sending an M999 command, or powering off the duet. In that case, X and Y works wonderfully when I home them individually. Furthermore, the X and Y portions of the Home All function work as intended as well.

Great.

So with X and Y homed:

move X and Y to center of the bed either by jogging or issuing G1 commands
issue a G92 Z3 to force Z to be marked as homed (this allows jogging Z)
jog Z to 3 mm off the bed (now the logical and physical Z positions are in sync)
change to the DWC Console page
issue a G30

Post what happens.

Frederick

Charlie

@fcwilt
So I did this, but with one exception. I didnt jog the z to be 3mm off the bed, as I was concerned about crashing the nozzle.

The probe did not deploy, and the error: "Error: Probe was not triggered during probing move" was displayed on the console.

Charlie

@joergs5 said in BLTouch Probe Won't Deploy:

@charlie a last additional idea: M208 has Z minimum 0 and the BLTouch starts at 3 mm height. It may be that it cannot probe below 0 because of M208. This was changed in 3.4 somewhere if I remember correct, but if you use 3.3 firmware, it may be a try to set the M208 Z limit below 0.

Something odd happened that may help those smarter than I!

I issued an M208 S1 Z-100 command in the DWC console (which is along the lines of what I believed you asked me to do). I then issued a G30 command. Please keep in mind that this was after I did what @fcwilt asked, which was to issue a G92 Z3 command.

The print head seemed to move down around 3mm, and then the probe deployed.

fcwilt

I made a post but came back to find your new post.

I need to think.

fcwilt

@charlie

OK what are your current probe configuration commands (M950 M558 G31)?

Frederick