BLTouch working

Biggsis

Alright, I have a BLTouch mostly working with my Duet Wifi, G29 is working, map is created and used so far, but I somehow dont get the maths right.
I am using the BLTouch as the Z-Min Endstop and it works so far, bed touches the pin, stops. etc.
But how do I get the right value for the Z-Offset of the probe right?

I have this line:

G31 X40 Y5 Z1.00 P25

the X and Y offset was measured by me, but the Z offset is not the right value, I was more or less just guessing and when I start printing the nozzle is far too close to the bed and I have to BabyStep lift the nozzle by 0.55 mm up in order to print usable on the bed.

Now I am aware that I should change that offset value but where to? Add .55 to the G31 Z Value? Or subtract? I dont get it since I guess I did not completely understand, what the Z offset in the G31 line really is. The distance between the trigger height of the probe and the tip of the nozzle?

Maybe someone can enlighten me about the correct procedure / maths.

Thanks a lot.

Sabagmn

Correct. The Z offset is the difference between the trigger height of the probe and the height of the nozzle tip. So in your case that would be around 0.45, which would be what you put as your Z value.

It basically just means that when your probe triggers, it will know that the nozzle is still 0.45mm above the bed.
Here are good instructions for finding the correct value:
https://duet3d.com/wiki/Using_mesh_bed_compensation

Motalw

@claustro:

@dc42:

Have you read https://duet3d.com/wiki/Using_mesh_bed_compensation ?

I have another problem , when I home the Z probe seems to work perfectly, the printer register the touch point and the home Z button become blue . The problem is the probe that after touching the bed with the pin it start flashing and I have to reset it manually https://www.youtube.com/watch?v=eq2wTy3-kxA
this is my homing routine

[c]G91 ; relative mode
G1 Z4 F200 ; raise head 4mm to ensure it is above the Z probe trigger height
G90 ; back to absolute mode
M98 Pdeployprobe.g
G1 X150 Y150 F2000 ; put head over the centre of the bed, or wherever you want to probe
G30 ; lower head, stop when probe triggered and set Z to trigger height[/c]

Hope you'll be able to understand my very mad English

I have the same problem when the pin drops after homing Z but it doesn't always happen. did anyone have this problem? and how did you fix it?
Also, my homing only works with M558 P1 instead of P5. any idea why?
all connections are correct as far as I know.

Nylkos

No idea, but you seem to be in the same boat has I…

What I had to do:
Like in https://duet3d.com/wiki/Connecting_a_Z_probe
but use P1 instead of P5 and change your P value in G31 (I used P200)

M307 H3 A-1 C-1 D-1 ;
M558 P1 X0 Y0 Z1 H5 F100 T2000
G31 X0 Y0 Z0 P200
use deployprobe.g (M280 P3 S10 I1)& retractprobe.g (M280 P3 S90 I1)

Thread
Source:https://www.duet3d.com/forum/thread.php?id=2539&p=2

Can you post your homez.g file?

I do not have access to my file from work but I might be able to help.

Motalw

I'm at work right now but I believe my Homez is:

; homez.g
; Lift Z relatively to current position
G91
G1 Z5 F6000

; Back to absolute positioning
G90

; Go to first bed probe point and home the Z axis
G1 X15 Y15 F6000
G30

; Uncomment the following lines to lift Z after probing
;G91
;G1 Z5 F100
;G90

one thing came to my mind now… maybe I have used the 10k resistor instead of the 240 ohm. need to double check it when I get home.
would it be a possible explanation?

Nylkos

@Motalw:

I'm at work right now but I believe my Homez is:

; homez.g
; Lift Z relatively to current position
G91
G1 Z5 F6000

; Back to absolute positioning
G90

; Go to first bed probe point and home the Z axis
G1 X15 Y15 F6000
G30

; Uncomment the following lines to lift Z after probing
;G91
;G1 Z5 F100
;G90

did you create deployprobe.g (M280 P3 S10 I1) & retractprobe.g (M280 P3 S90 I1)?
If no, you need to create those files with the command ()
Once you have them, add the Pdeployprobe.g & Pretractprobe.g command in your homez.g file:

M98 Pdeployprobe.g
; Go to first bed probe point and home the Z axis
G1 X15 Y15 F6000
G30
M98 Pretractprobe.g

To test, click manually home X, Home Y, Home Z, do not click home all.

Let me know how it goes

Nylkos

I forgot to mention:
You can try to use the M401 & M402 command instead of the deployprobe.g & retractprobe.g,
I have to use deployprobe.g & retractprobe.g, but I was having issues with the BLTouch.

For me, the M401 & M402 command were working with the M558 P5, but not with the M558 P1

Nylkos

I am suggest that you create a resetalarm.g (your call on the name) file with M280 P3 S160 I1.
That way, you can cancel the alarm by using

M98 Presetalarm.g

instead of remembering the M280 P3 S160 I1 command or resetting your printer.

Motalw

@Nylkos:

I forgot to mention:
You can try to use the M401 & M402 command instead of the deployprobe.g & retractprobe.g,
I have to use deployprobe.g & retractprobe.g, but I was having issues with the BLTouch.

For me, the M401 & M402 command were working with the M558 P5, but not with the M558 P1

I had the same problem it would not deploy or retract using M401 & M402.
I have to check that resistor… Also need to check if I have any config override file. because all the rest is right I believe.

Motalw

@Nylkos:

I am suggest that you create a resetalarm.g (your call on the name) file with M280 P3 S160 I1.
That way, you can cancel the alarm by using

M98 Presetalarm.g

instead of remembering the M280 P3 S160 I1 command or resetting your printer.

I have add it to my Default G-Codes (drop down menu).

Nylkos

Were you able to test your homez.g?

Motalw

@Nylkos:

Were you able to test your homez.g?

Not yet, I'm working till late tonight. I'll post a feed back Around 9pm.
and yes I do have the files retract & deploy. I did add it to bed.g & homeall.g but forgot about homez.g.
But if I'm not wrong I believe it deploy and retract the probe automatically when i use G30.

Motalw

@Nylkos:

Were you able to test your homez.g?

I have tested it but it work just as my configuration without theM98 commands.
I also I'm using the correct resistor.
ever thing works "almost" fine if I use M558 P1 but the probe drops some time.
this is my configuration maybe I missed some thing;

; Configuration file for Duet WiFi (firmware version 1.17)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Tue Sep 19 2017 08:19:05 GMT+0100 (GMT Daylight Time)

; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates…
M83 ; ...but relative extruder moves
M555 P2 ; Set firmware compatibility to look like Marlin

M667 S1 ; Select CoreXY mode
M208 X0 Y0 Z0 S1 ; Set axis minima
M208 X430 Y330 Z450 S0 ; Set axis maxima

; Endstops
M574 X1 Y1 Z0 S0 ; Define active low and unused microswitches
M558 P1 X0 Y0 Z1 H5 F120 T9000 ; Set Z probe type to unmodulated, the axes for which it is used and the probe + travel speeds
G31 P10 X0 Y40 Z2 ; Set Z probe trigger value, offset and trigger height
M557 X15:415 Y15:315 S20 ; Define mesh grid

; Drives
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S1 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S1 ; Drive 4 goes forwards
M569 P5 S1 ; Drive 5 goes forwards
M350 X16 Y16 Z16 E16:16:16 I1 ; Configure microstepping with interpolation
M92 X100 Y100 Z400 E383:383:383 ; Set steps per mm
M566 X1200 Y1200 Z12 E240:240:240 ; Set maximum instantaneous speed changes (mm/min)
M203 X6000 Y6000 Z180 E3000:3000:3000 ; Set maximum speeds (mm/min)
M201 X500 Y20 Z250 E250:250:250 ; Set accelerations (mm/s^2)
M906 X1200 Y1200 Z1500 E800:800:800 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Heaters
M143 S275 ; Set maximum heater temperature to 275C
M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1

; 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
M563 P1 D1 H1 ; Define tool 1
G10 P1 X0 Y0 Z0 ; Set tool 1 axis offsets
G10 P1 R0 S0 ; Set initial tool 1 active and standby temperatures to 0C
M563 P2 D2 H1 ; Define tool 2
G10 P2 X0 Y0 Z0 ; Set tool 2 axis offsets
G10 P2 R0 S0 ; Set initial tool 2 active and standby temperatures to 0C

; Network
M550 PUltima Bot ; Set machine name
M552 S1 ; Enable network
; Access point is configured manually via M587 by the user
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet

; Fans
M106 P0 S0.3 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
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

; Custom settings
M307 H7 A-1 C-1 D-1 ;disable heater 7 on pmw5

; Miscellaneous
T0 ; Select first tool

Bed.g

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool on Mon Sep 18 2017 19:18:06 GMT+0100 (GMT Daylight Time)

; Clear any bed transform
M561

; Deploy the mechanical Z probe
M98 Pdeployprobe.g

; Probe the bed at 5 points
G30 P0 X15 Y15 H0 Z-99999
G30 P1 X15 Y315 H0 Z-99999
G30 P2 X415 Y315 H0 Z-99999
G30 P3 X415 Y15 H0 Z-99999
G30 P4 X215 Y165 H0 Z-99999 S
; Retract the mechanical Z probe
M98 Pretractprobe.g

Homeall.g

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool on Mon Sep 18 2017 19:21:01 GMT+0100 (GMT Daylight Time)

; Relative positioning
G91

; Lift Z
G1 Z5 F9000

; Deploy the mechanical Z probe
M98 Pdeployprobe.g

; Course home X and Y
G1 X-435 Y-335 F3600 S1

; Move away from the endstops
G1 X5 Y5 F9000

; Fine home X and Y
G1 X-435 Y-335 F360 S1

; Absolute positioning
G90

; Go to first bed probe point and home Z
G1 X15 Y15 F9000
G30

; Uncomment the following line to lift the nozzle after probing
;G1 Z10 F150

; Retract the mechanical Z probe
M98 Pretractprobe.g

Homez.g

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool on Tue Sep 19 2017 08:11:32 GMT+0100 (GMT Daylight Time)

; Lift Z relatively to current position
G91
G1 Z5 F9000

; Back to absolute positioning
G90

; Go to first bed probe point and home the Z axis
G1 X15 Y5 F9000
G30

; Uncomment the following lines to lift Z after probing
G91
G1 Z5 F150
G90

Nylkos

What are your values in Z-Probe for triggered and deploy?

Motalw

The shows 4 some times 5 when triggered and 0 when not triggered. (using M558 P1)
If I uses M558 P5 then it will always be 0.

Motalw

just run a mesh grid and this was the results :

share pics online
I'm Almost giving up on this … I have tried the DC42 IR Probe but because my heatbed is glass when I use tape or ABS juice on the surface the IR probe needs to be re-calibrated.

Nylkos

I just noticed that in your HomeZ.g you do not deploy or retract.

Motalw

@Nylkos:

I just noticed that in your HomeZ.g you do not deploy or retract.

it is not necessary because the firmware does it automatically when G30 is called. but I have tried it with the deploy and retract code but did not make any difference.
I have now just tried to do a mesh levelling using the DC42 IR Probe and this was the result;

I have a aluminium heat bed painted black and with a 6mm sheet of glass on top of it so it is 100% flat. I dont know why I keep get this results with the BLTouch and the IR Probe. any idea?

Motalw

just did a mesh grid using the BLTouch and another with the DC42 IR Probe. can anyone help with it?why both of then are giving bad results?
BLTouch

DC42 IR Probe

Nylkos

How is your bed mounted, is the movement smooth or staggered at low and fast speed