Z-probe triggers way above table during HOME ALL

[Billsrf]

@dc42 my IR Z-probe has started triggering way above the table during the home.all movement. But, once you have home.all, you can push Z-home and it performs the correct Z-movement at the correct height. I can not find anything that has changed. Worked flawlessly for over 1000 hours of print time, now this just showed up. Any suggestions???0_1555958591161_config.g 1_1555958650642_homez.g 0_1555958650641_homeall.g

[dc42]

Various possibilities:

• If it's the old style sensor with through hole optical components, those components may have been bent out of position
• Has the bed surface changed? Some sensors trigger at large heights when the bed is highly reflective.
• Is there bright sunlight (no clouds in front of the sun) shining directly on the bed? That can saturate the sensor, and the LED will blink rapidly to indicate this.
• Have the optical components become contaminated with filament or dust? You can clean them using a cotton bud moistened with isopropanol.

[Billsrf]

@dc42 said in Z-probe triggers way above table during HOME ALL:

If it's the old style sensor with through hole optical components, those components may have been bent out of position
Has the bed surface changed? Some sensors trigger at large heights when the bed is highly reflective.
Is there bright sunlight (no clouds in front of the sun) shining directly on the bed? That can saturate the sensor, and the LED will blink rapidly to indicate this.
Have the optical components become contaminated with filament or dust? You can clean them using a cotton bud moistened with isopropanol.

Nothing has changed. I even swapped out the sensor for a new one. Same exact thing.
I even went back and uploaded the firmware again, no change.

My big question is, why it works perfectly when i use HOME Z, but not HOME.ALL?

[dc42]

When it triggers prematurely, does the red LED on the sensor illuminate?

[Billsrf]

How do check that? I attached my config.g, home.all and home.z files. my home.all calls for a G30 to trigger and the config.g z-probe calls for a G31 at the same point. When I change the G31 in the config file to G30, it crashed into the bed without triggering, so I changed it back to G31

[Billsrf]

swap that, HOME.ALL calls for G30, CONFIG.G calls for G31, HOME.Z calls for a G30

[dc42]

@billsrf said in Z-probe triggers way above table during HOME ALL:

How do check that?

By observing it when you run homeall. When it stops prematurely, also look at the Z probe reading in DWC, or send G31 without parameters to report it.

[Billsrf]

@dc42 yes it flashes just like it is at the bed

[dc42]

@billsrf said in Z-probe triggers way above table during HOME ALL:

@dc42 yes it flashes just like it is at the bed

Can you confirm that it flashes just once? Not 2 or 4 times, like it does when it initialises?

[Billsrf]

it is roughly 50mm above the bed, it flashed 1 time just like normal then moves up 5mm.

[Phaedrux]

G31 P500 X570 Y570 Z0

This looks a little off from your config.g.

Is the probe really X570 and Y570 away from your nozzle?

You also haven't calibrated the Z trigger height.

[Billsrf]

after home.all, I can push HOME.Z and it moves to the bed and sets the correct nozzle height

[Billsrf]

@phaedrux i have the offset Z trigger height set to zero for testing. What should the X-Y settings be for the G31? isnt it center of my build plate?

[Phaedrux]

@billsrf The X and Y values for G31 should be the distance of the probe from the nozzle. Just as the Z value is the distance from the probe to the nozzle tip in Z.

If the probe is to the left, the value will be -x.
If the probe is to the right, the value will be +x.
If the probe is to the front, the value will be -y.
If the probe is to the back, the value will be +y.

[Billsrf]

my BED.G looks like it is missing a lot of information now for some reason. 0_1555961191732_bed.g

[Phaedrux]

It looks like your bed.g is currently setup to just do a mesh grid compensation run.

[Billsrf]

@phaedrux ok, i will measure the offset and change that in the G31 in config.g

[Billsrf]

If I am not using a bed compensation. Why would that be making my trigger so high off my build surface? It moves down about 20 mm then triggers during home.all. But, if i do a home.z afterwards it moves to the correct trigger height and it is ready to go

[Phaedrux]

Have you gone through these steps?

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

[Billsrf]

yes 9 times. I will change the offsets and then go through the probe set up again