BL Touch Help Needed Please

Asdasd1234

ah, In that case, I need to find out if its safe to take off the resistor for a couple runs.
I dont suppose @dc42 could chime in on that one?

dc42

Yes you have a Duet WiFi.

The first thing to check is that with the BLTouch connector disconnected from the Z probe connector, you get a Z probe reading of 1000. If you don't then there is probably an error in the configuration.

It should be safe to remove the 240 ohm resistor because the Z probe input is quite well protected.

Asdasd1234

Woooo!!!!!!
removing the 240 ohm resistor seems to have done it. (along with changing all those settings above that people mentioned )

That'll teach me to buy cheap I suppose. I measured the voltage across the black and white leads and only read 1.3v on the multimeter while it was in the error state flashing at me . But that may have been due to it pulsing like a pwm signal and the multimeter just averaging it. Who knows.

What i do know is that it seems to be working now!

I'll still bust out the oscilacope tomorrow to see what on earth is actually going on with that signal.

Many thanks to everyones input, its been a great help!, we kinda dived into the deep-end on this build and went all on building a printer from having never owned one before and although the building part was pretty straight forward, I massively underestimated the software side of things.

Juergen110

Hi garyd9,
@garyd9:

While I doubt this relates to your specific problem, I noticed that you use "G92 Z2" after G30. Once you get your G31 command set up to reflect the Z trigger height, remember to remove the G92 command that sets "Z".

G30 – sets Z to the trigger height specified in G31 when the probe triggers
G92 Z2 -- overwrites the Z value to 2.0

Oups….
Thanks a lot for this Reminder ! You are right !
I also forget to remove it. In my Case, it doesn´t matter, because it is the same Value in there.
But it makes sense to remove.

Juergen110

and some additional Thing to Asdad1234, but maybe you already know:
If you want to use the "Mesh-Grid" and Auto-leveling Function, please remind that you don´t start with an G28 in your Slicer-Program !
Most generate automatically a Start-Code, that Contains only the G28.
You need to replace it with an G29 Command (or later with an G29 S-1 if you already created the File and has no Changement)

I was stucked on this funny small Issue, and wondering why i don´t get an Automatic Leveling when i start a Test-Print…..

After i found this, it runs pretty well.
Also when i change my Print-Platform to another, lightly deformed Glass Plate, i directly have a perfect First Layer

Asdasd1234

Thanks for the info Jeurgen,

I only use the "load mesh bed from file" command in the slicing setup so hopefully that's not an issue for now.

I don't think I can get away with using the z-probe for the actual mesh levelling due to :

The sensor is about 5cm away from the nozzle
I'm using the mesh to combat carriage sag rather than a warped bed so the readings will be off in one direction to the left of the bed and the other direction to the right of the bed.

On a slightly un-related note. Is there any way to change the increments I can move the z-axis in when doing the manual mesh bed levelling?
Currently the pop-up window only lets you move in 0.1mm increments, which is potentially a full layer high later on. I have a feeler guage 0.01mm thick so it would be nice to actually level the bed down to the correct level rather than "give or take half a layer"

Juergen110

Hi Guys,
yesterday evening i found out that i also need some more Help…..

What happend:
After the Reminder from Gary (Thanks!) i remove the "G92 Z2" from my homez.g , after it Probes with G30.
Unfortunately then it DON`T set the Value for the Z-Axis to 2
And it also don´t switch the Z-Axis "Home-Button" to Blue and still says that Z is not Homed
BUT: it stopped the Axis from Moving, when the BL-Touch is triggered.

Now i´m a little bit lost..... What could be wrong ??
WITH additional G92 everything works well. I could home the Axis, could do the Mesh-Bed-Leveling, and also the Print_Layers are perfect....
This is in my Config.g

; Endstops
M574 Y0 X0 S0 ; Set active high endstops
M574 Z1 S2 ; Set endstops controlled by probe
M307 H3 A-1 C-1 D-1 ;
M558 P5 X0 Y0 Z1 H5 F100 T2000
G31 X0 Y20 Z2 P25

Why it ignore´s the Z-Value from the G31 Command when i run that G30 ??

Here´s my homez.g again (that works with G92, but not without it….)

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool on Fri Jan 19 2018 18:24:18 GMT+0800 (China Normalzeit)
G91 ; relative positioning
G1 Z5 F6000 ; lift Z relative to current position
M98 Pdeployprobe.g ;deploy the probe
G30 S-1 ; move Z down until the switch triggers
G92 Z2 ; set Z position to trigger height
M98 Pretractprobe.g ;retract the probe after triggering and stop.

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

Any recommendations or Tips, what i should check or try, are welcome

I also try yesterday to get the BlTouch in Error-Mode. THEN the Value in Web-Interface change to 1000 and is red.
All other Times, i only see a Value of 0

garyd9

@Juergen110:

Any recommendations or Tips, what i should check or try, are welcome

Remove the "S-1" from the G30 command. Just a plain old "G30" is what you want.

Just to put it out there, I'll post my config and homing stuff. I'm using what used to be a flashforge creator pro and I like the center of my build plate to be 0,0 (so anything to the left or front of center is negative.) Don't let that confuse you.

The related part of my config.g:

[[language]]
M574 Z1 S2                                    ; this allow me to use the z-probe as if it were an endstop (which comes in handy for doing G1 S1)
M307 H3 A-1 C-1 D-1			; ensure the servo pin is used for the probe * warning: overrides might override this **
M558 P5 X0 Y0 Z1 H5 F100 T4000		; set z-probe type to 5, dive height and speeds
G31 X-73.2 Y-0.8 Z0.83 P25		; configure the z-probe trigger value, offset, and threshold
M557 X-111:75 Y-70:70 S20                            ; Define mesh grid
M671 X1.1:-50:49 Y-69.2:65.5:65.5 P0.5   ; level screw locations and screw pitch type

And part of my homeall.g script (at the point where I'm posting, X and Y are already homed, there's at least 5mm separation between my nozzles and build plate, and the printer is in absolute positioning (G90)

[[language]]
; now home z - still in absolute positioning, z is still at least 5mm from the plate, and T1 is selected
;
; front/center adjustment screw is at X1.1 Y-69.2 and the probe is offset from T1 by X-73.2 Y-0.8
;
G1 X74.3 Y-68.4 F6000  ; position the probe over the front/center screw adjustment point (offsetting from T1)
G91			; relative positioning
M401			; deploy the probe
G1 S1 Z-155 F6000	; quickly move Z down, stopping at the probe (possible because of M574 Z1 S2 in config.g)
G1 Z5 F1200		; immediately move the nozzle 5mm away from the build plate
M401			; make sure the probe is deployed still
G30			; slowly probe at the current position and set Z to the trigger height (this sets Z to 0.83 when the trigger happens)
M402			; retract the probe

Juergen110

Hi Gary,

Just a plain old "G30" is what you want.

after i´m back Home, i will directly try !
Thanks a lot !!!!
crazy, what a misplaced and simple S-1 would do….

And a short Feedback:
Gary, you were absolutely Right !!!!
After i delete the S-1, everything works without the additional "G92"

THANKS A LOT !!!

Asdasd1234

Hi all,

Just a thing to mention for everyone else in case you do something stupid like me…

Make the deploy pin the FIRST command in your homez, or at least make the first command to move the bed out the way...
I'm sure you can all guess what happens if you don't as I found out yesterday when I snapped the pin off the bl-touch