Z-Offset to low - BLTouch, Duet Wifi 2

Veti

print a flat first layer. while printing adjust with babystepping.
once you find a good setting adjust the offset with the offset from the babystepping.

Veti

@calibanorg said in Z-Offset to low - BLTouch, Duet Wifi 2:

2.04RC3

also i believe there was a bltouch bug in on of the rc releases. please update to the stable 2.04 version

calibanorg

@Veti thanks for the fast reply to my question - It worked i have a really good layer as it should be

So what i did:

I updated first to 2.04 as recommended -> not sure if that helped but i have experience some unwanted pin deployment after a few seconds of the print start.
I downloaded the this flat test square https://www.thingiverse.com/thing:3896687 and started the print as suggested.
then i started to do the babysteps (+) as suggested until i found the layer looks good (result was +250) so i removed it from G31 P25 X21 Y0 Z0.608 which gave me the new result G31 P25 X21 Y0 Z0.358

A note to the last point: i first added it to Z0.608 in G31 which resulted to Z0.850 which put the nozzle much closer. For me a higher number results to higher distance to the bed, but this not the case with this CoreXY configuration.

@Veti i guess you might have simple explanation for that?

Anyway thank you so much @Veti i struggled now weeks with this. I read so many forums and howto description and i didn't find anything like what you mentioned to change the offset after the trigger height measurement.

Calibration print - 1 Layer

Print after i change G31

Veti

@calibanorg said in Z-Offset to low - BLTouch, Duet Wifi 2:

@Veti i guess you might have simple explanation for that?

yes. its simple but i get this wrong some times as well.

your babystepping was +0.25mm. that mean the head had to be moved up.

now a trigger height of 0.6mm means that when the probe touches your bed the distance from there to the nozzle is 0.6mm

So with this this offset if you start the print the nozzle moves 0.6mm closer to the bed.

if you increase the offset to 0.9mm the nozzle now needs to move 0.9 mm closer to the bed when printing. thus squashing into the bed.

calibanorg

@Veti said in Z-Offset to low - BLTouch, Duet Wifi 2:

if you increase the offset to 0.9mm the nozzle now needs to move 0.9 mm closer to the bed when printing. thus squashing into the bed.

Okay make sense thanks. With my coreXY the head doesn't move but the bed goes up or down.

In regards of the odd deploy off the BLtouch pins during print. It just happend during an 8hrs run and it destroyed my print plus the BLtouch itself was crashed ::(

dc42

Are you definitely running 2.04 final release, not a 2.04RC version? Send M115 to check.

Veti

@calibanorg said in Z-Offset to low - BLTouch, Duet Wifi 2:

In regards of the odd deploy off the BLtouch pins during print.

i am not a big fan of the bltouch. i build this for myself https://www.thingiverse.com/thing:3303618

calibanorg

@dc42 i did the check as suggested. below the result:```

M115
FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 2.04 ELECTRONICS: Duet WiFi 1.02 or later FIRMWARE_DATE: 2019-11-01b1

That is the final release correct?

calibanorg

@Veti so i tried to repair my BLtouch and accidentally cut the electromagnetic wires so now it is definitely gone. so your suggestion comes at the right time. i think i might have all parts somewhere...

calibanorg

@Veti said in Z-Offset to low - BLTouch, Duet Wifi 2:

@calibanorg said in Z-Offset to low - BLTouch, Duet Wifi 2:

In regards of the odd deploy off the BLtouch pins during print.

i am not a big fan of the bltouch. i build this for myself https://www.thingiverse.com/thing:3303618

I build the sensor you suggested this weekend due i had all material on hand. The sensor is amazingly easy to build and it worked quite right away.

Regarding the config i only changed M558 to P5. But based on the documentation -> https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe "Mode 2" = P2 is might be more suitable?

Again thanks @Veti you saved me 50 Bugs for a new BL Touch

Veti

the ir endstops are either triggered or not. so P5 is the correct one.