Servo deployed probe on Duet Maestro

Phaedrux

Smaller servos can burn out if forced in a way they can't go.

Blacksheep99

@Phaedrux That's likely what has happened. I plan to take it out later. I've ordered a new one in case it has. I'll test it out of the printer.

Blacksheep99

I've replaced the servo and the probe now deploys. It seems to work fine when I issue M401 and it retracts to M402.

In the dashboard my probe is showing as 1000. I'm a bit lost with this part. I've defined it as a switch with P8.

The nipple microswitch (for want of a better description) I'm currently using has two wires, so different to a microswitch I'm used to where there are 3 connection points. It's a Zippy switch. I'm trying to work out the two wires which at the moment I have one connected to the 3.3v on the zprobe header and the other to the zprobe.in.

Phaedrux

And what do you have in your M558 line? It may need to be inverted.

Blacksheep99

@Phaedrux This is what I currently have.

M950 S0 C"^zprobe.mod" 							; create servo pin 0 for BLTouch
M558 P8 C"^zprobe.in" H5 F120 T6000 			; Set Z probe type to switch and the dive height + speeds
G31 P1000 X-20 Y-10 Z15 						; Set Z probe trigger value, offset and trigger height

Phaedrux

Try this

M558 P8 C"^!zprobe.in" H5 F120 T6000
G31 P500 X-20 Y-10 Z15

Blacksheep99

@Phaedrux Thanks, it's now showing as 0!

Blacksheep99

So I'm following the test guidance. To manually test. I've just ran G30 and the probe deploys and Z starts to move up but then an error is triggered.

G30
Error: Z probe was not triggered during probing move

It may be one for the morning.... a clear head and do some more reading.

Phaedrux

@Blacksheep99 said in Servo deployed probe on Duet Maestro:

Z starts to move up

This is ambiguous. Do you mean the probe and the bed are getting closer together?

G31 Z15 means the nozzle is 15mm above the bed when the probe triggers? Is that correct? Yet your dive height is only 5mm M558 H5.

Blacksheep99

@Phaedrux said in Servo deployed probe on Duet Maestro:

@Blacksheep99 said in Servo deployed probe on Duet Maestro:

Z starts to move up

This is ambiguous. Do you mean the probe and the bed are getting closer together?

G31 Z15 means the nozzle is 15mm above the bed when the probe triggers? Is that correct? Yet your dive height is only 5mm M558 H5.

Sorry, I'll try be more clear. The bed starts to move up towards the nozzle which is on a fixed XY. The probe deploys immediately.

No the nozzle is close to the max 150mm build height. I've clearly misunderstood that part of the code.

Phaedrux

Now that you have it working give this a shot

https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe

Your dive height should be slightly higher than your trigger height.

Blacksheep99

@Veti said in Servo deployed probe on Duet Maestro:

i am using this

https://www.thingiverse.com/thing:3303618

and it works on the maestro.

all the connections are going to the z probe header.

gnd is combined and 5v is combined in this case.

So I've ditched my old probe and made one of these today. I've connected it up and it seems to be working as it should. I just can't get my head around what I need to get this to work with my printer. By that I mean bring the bed up, probe deploy and then bed probed.

I'd appreciate some guidance, just to help my understanding.

Veti

@Blacksheep99

its pretty close to bltouch. just select P8 instead of p9.

same retract and deploy scripts (might have to adjust the angles slightly)
although you need to add a M401 if you want to deploy it before and M402 when you want to retract.

example homeall

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v3.2.0 on Fri Jan 01 2021 18:39:48 GMT+0100 (Central European Standard Time)
G91                     ; relative positioning
G1 H2 Z5 F6000          ; lift Z relative to current position
G1 H1 X-240 Y-240 F3000 ; move quickly to X and Y axis endstops and stop there (first pass)
G1 H2 X5 Y5 F6000       ; go back a few mm
G1 H1 X-240 Y-240 F240  ; move slowly to X and Y axis endstops once more (second pass)
G90                     ; absolute positioning
G1 X10 Y10 F6000        ; go to first bed probe point and home Z
M401
G30                     ; home Z by probing the bed
M402

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

Blacksheep99

@Veti Thanks, I'll give this a try when I finish work. What about my config.g file? or does this replace what's currently in there?

Blacksheep99

@Veti said in Servo deployed probe on Duet Maestro:

@Blacksheep99

its pretty close to bltouch. just select P8 instead of p9.

same retract and deploy scripts (might have to adjust the angles slightly)
although you need to add a M401 if you want to deploy it before and M402 when you want to retract.

example homeall

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v3.2.0 on Fri Jan 01 2021 18:39:48 GMT+0100 (Central European Standard Time)
G91                     ; relative positioning
G1 H2 Z5 F6000          ; lift Z relative to current position
G1 H1 X-240 Y-240 F3000 ; move quickly to X and Y axis endstops and stop there (first pass)
G1 H2 X5 Y5 F6000       ; go back a few mm
G1 H1 X-240 Y-240 F240  ; move slowly to X and Y axis endstops once more (second pass)
G90                     ; absolute positioning
G1 X10 Y10 F6000        ; go to first bed probe point and home Z
M401
G30                     ; home Z by probing the bed
M402

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

So taking your example I modified my home all to try this. I changed the X and X to my bed size. Sending just the M401 command deploys the probe fine, the M402 retracts it.

This is my config.g code.

M574 Z1 S1 ; Set endstops controlled by probe
M950 S0 C"^zprobe.mod" ; create servo pin 0 for BLTouch
M558 P8 C"^!zprobe.in" H2 F900 T6000 ; Set Z probe type to switch and the dive height + speeds
G31 P50 X50 Y-8 Z2.43 ; Set Z probe trigger value, offset and trigger height

When I home all the head moves out as expected, the bed starts to raise, probe deploys and the immediately retracts and the z stops.

My probe in the dashboard shows 0 when retracted and 1000 when deployed. Is the inverted pin causing an issue?

Blacksheep99

This is the bed and head setup. Excuse the chaos behind it!

Phaedrux

@Blacksheep99 said in Servo deployed probe on Duet Maestro:

Is the inverted pin causing an issue?

Could be. Your description makes it sound like it assumes that it's triggered as soon as it deploys? Correct?

dc42

@Blacksheep99 said in Servo deployed probe on Duet Maestro:

My probe in the dashboard shows 0 when retracted and 1000 when deployed. Is the inverted pin causing an issue?

What happens if you don't invert the pin? Does probing work then?

Veti

@Blacksheep99 said in Servo deployed probe on Duet Maestro:

My probe in the dashboard shows 0 when retracted and 1000 when deployed. Is the inverted pin causing an issue?

yes it needs to be inverted

change to C"^zprobe.in"

Blacksheep99

@Veti said in Servo deployed probe on Duet Maestro:

@Blacksheep99 said in Servo deployed probe on Duet Maestro:

My probe in the dashboard shows 0 when retracted and 1000 when deployed. Is the inverted pin causing an issue?

yes it needs to be inverted

change to C"^zprobe.in"

Ok, I've changed this. The probe itself is off the bed. Do I need to add a move command for X and Y to move the head over the bed?

I current have the mesh compensation commented out in the config.g not sure if that should be active?