New IR z probe issues

droftarts

@agent0810 said in New IR z probe issues:

and to be clear, what i put in G31 Z is the output on the console right? so i would put in 1.501 for this?

7/21/2020, 10:55:50 PM G30 S-1
Stopped at height 1.501 mm

Yes, that's correct. You can send G31 Z1.501 in the console, then send G31 to check it is set, eg my G31 response is:

G31
Z probe 0: current reading 0, threshold 500, trigger height 1.250, offsets X20.0 Y0.0

Test that the probe is functioning correctly by homing Z, then move Z to 0 and check the nozzle is just touching the bed. Then modify your G31 line in config.g, so that the new setting persists after a reset. Change G31 line in config.g to:

 G31 P500 X0 Y0 Z1.501 ; set Z probe trigger value, offset and trigger height

Ian

agent0810

@droftarts thank you!

did as you asked and it is still a little to high, its not pushing the filament onto the glass bed.

agent0810

@droftarts

i have it zeroed in the middle of the bed. this is what i see on my web interface, that normal?

droftarts

@agent0810 Adjust with 'Z babystepping' (on the Status tab of DWC), until you're happy with how the first layer is going down. Presumably you'll need raise the bed a little, so this may be -0.1mm of babystepping, so you can reduce the G31 Z height by 0.1mm. If you do this, don't forget to reset babystepping (with M290 R0 S0) if you don't reset the printer.

Have you calibrated your extruder, though? If you haven't, it may be underextruding, which will also make it look like the nozzle is too far off the bed. So get that right, too.

Ian

droftarts

@agent0810 said in New IR z probe issues:

i have it zeroed in the middle of the bed. this is what i see on my web interface, that normal?

What do you mean, zeroed? If you want X0 Y0 to be in the middle of the bed, you need to adjust M208. At the moment yours is set to:

; Axis Limits
M208 X0 Y0 Z0 S1 ; set axis minima
M208 X225 Y225 Z300 S0 ; set axis maxima

So it's not surprising that, with the nozzle in the middle of the bed, X and Y are 120. To get X0 Y0 to be in the middle, you'll want something like:

; Axis Limits
M208 X-120 Y-120 Z0 S1 ; set axis minima
M208 X120 Y120 Z300 S0 ; set axis maxima

See https://duet3d.dozuki.com/Wiki/Centering_the_bed_or_setting_the_bed_origin

Ian

agent0810

@droftarts

started printing and had to z babyset +.05 to 1mm to get it where i need it.
Current Offset: 1.00 mm

what do i need to do to keep it here?

agent0810

@droftarts
print came out amazing, just need to have it default to the 1mm babystep.

fcwilt

@agent0810 said in New IR z probe issues:

@droftarts
print came out amazing, just need to have it default to the 1mm babystep.

While you can change the baby step setting in code you can also adjust the the trigger height setting of your Z probe to achieve the same thing - which is what I do.

If you used baby stepping to move the nozzle closer to the bed increase the trigger height setting by that amount.

If you used baby stepping to move the nozzle away to the bed decrease the trigger height setting by that amount.

Frederick

agent0810

@fcwilt
so if im currently at
G31 P500 X50 Y0 Z1.501

and my current offset was 1 mm that i had to move the nozzle away from the bed. i need to decrease the Z from 1.501 to .501?

so

G31 P500 X50 Y0 Z.501?
i am fairly positive that i have tried that and it didnt work

Phaedrux

A larger G31 value results in the nozzle being closer to the bed.

fcwilt

@agent0810 said in New IR z probe issues:

@fcwilt
so if im currently at
G31 P500 X50 Y0 Z1.501

and my current offset was 1 mm that i had to move the nozzle away from the bed. i need to decrease the Z from 1.501 to .501?

so

G31 P500 X50 Y0 Z.501?
i am fairly positive that i have tried that and it didnt work

If you use baby stepping to move AWAY from the bed then the trigger height setting must be decreased.

If you're numbers are correct then that value is correct.

You can always determine the trigger height setting through trial and error, adjusting it up or down with G31, setting the Z=0 datum with G30 and repeating the process until moving to Z=0 has the nozzle just touching the bed.

Frederick

agent0810

@fcwilt
what is the P value in this line?

Phaedrux

trigger sensitivity.

agent0810

@fcwilt

i am not sure what i am doing wrong. i set it to the .501 and its still to far from the bed, filament isnt sticking. im not sure where to go from here. since it was to far away i lowered it to 0 and its still to far away.

Phaedrux

@Phaedrux said in New IR z probe issues:

A larger G31 value results in the nozzle being closer to the bed.

If it's still too far away you're going in the wrong direction. Instead of 0.5 you would need to add to the value, so 2.5.

droftarts

@agent0810 Think of it this way; when the probe triggers, it sets the Z height to the Z offset. So when it triggers, it sets Z to 1.5mm. If you then move the bed up to Z0, the nozzle should be touching the bed. If it's still away from the bed, the Z offset needs to increase. From your numbers, it should probably be around Z2.5.
There is also a guide to do this: https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe#Section_Calibrate_the_Z_probe_trigger_height

It may make a difference where you probe the bed. If you're homing over in the corner (and make sure the probe is homing over the bed if you do), then moving to the centre to print, it could be if your bed is not level, and the corner is lower or higher than the centre. You can check this manually (move the nozzle around to the corners of the bed, manually adjust bed level), or by getting mesh compensation going (https://duet3d.dozuki.com/Wiki/Using_mesh_bed_compensation) and looking at the mesh it creates. You can also do three point levelling manually, if you have bed adjusters; see https://duet3d.dozuki.com/Wiki/Using_the_manual_bed_levelling_assistant

Ian

jumpedwithbothfeet

@agent0810 I have an ender 5 and i have had exactly the same issue, its enough to drive you mad! but any way it seems if you follow this process exactly it helped me sort it out.

Important do NOT home the Axis's until the list tells you too!

Turnoff printer!
Turn on and go straight to config.g and change G31 Z to 0
save and reset board
heat bed to what ever temp you normally use and wait for it reach it (this is important on the ender 5 as the bed support is poor)
Heat nozzle to your most used temp and wait!
once both are heated now home all axis's ( i use the middle of the bed)
Jog Z to zero ( the nozzle should be well off the bed)
type M564 S0 into the console this will disable the axis limits
jog nozzle down until it touches the bed or paper which ever you prefer
type G92 Z0 into the console this resets the Z axis height
turn nozzle heater off (can affect the BLtouch touch sensor reading not sure regarding IR sensor)
now type G1 Z5 followed by G30 S-1 to do a single bed probe i made a macro to do this it helps!
probe the bed at least 5 or more times and go to the console and take the average trigger height.
save the trigger height in config.g G31 Z then the reset board and print! well after G29 that is

i'm sure you have carried out all these steps but it seems its the sequence that works, hope this helps!

Regards Jim

agent0810

Thank you for the reply! I appreciate all your guys help! I did exactly as you said and I’m still having issues. The back(furthest from me) is to high, the nozzle pushes up against it and no filament comes out. The side closest to me is a little to low, the filament doesn’t stick, thinking about putting some tin foil below the front to raise my glass bed up a bit in the front. Thoughts?

Phaedrux

Getting a good mechanical level to start with is always preferred.

agent0810

@Phaedrux does that mean you think the tin foil under the glass bed is a good idea? Thank you!