[BUG] UBL L Corner probing refuses to probe back corners.

[fraserreilly]

Description

Probing corners using UBL "L Corner" won't probe the back corners of the bed. Believes the Z probe is past the bed.

Steps to reproduce

1. Update TFT35 Firmware with bin.
2. Go to L corners via Movement -> Bed Level -> UBL -> L Corner.
3. Select a back corner.
4. Error message of "Z Probe Past Bed"

Expected behavior

Should probe the back left and right corners when selected.

Actual behavior

Prompts user with error "Z Probe Past Bed".

Hardware Variant

BTT TFT35 V3.0

TFT Firmware Version & Main Board Firmware details

BTT TFT35 V3.0 B1.27.x and Marlin 2.1.2.1

Additional Information

Probing corners will correctly move to the back corners if manually probing (Movement -> Leveling -> Point 3 or Point 4).

configuration.h paste

I have indented changes to configuration.h with "// CHANGED".

[kisslorand]

Are you on the latest build of the TFT firmware?
Anyhow, check what happens if you increase edge distance.

[fraserreilly]

@kisslorand Yep, latest build. Well, at least when using the precompiled bin. Increasing the edge distance seems to have fixed it! 60 is the minimum distance to get all 4 corners working.

[oldman4U]

Please help the community and close the ticket once you do not need it anymore. Thank you

[fraserreilly]

@oldman4U Although this is not resolved as it seems to be a calculation error (otherwise front should not work either) I don't have a resolution to provide and as no other users have reported this as an error I will close the issue. Please do reference this if others seem to be having the same issue.

[fraserreilly]

Opening this issue back up, I can't correctly level the printer without it fixed and as far as I can tell, it's not a configuration issue. The probe offset I have set #define NOZZLE_TO_PROBE_OFFSET { 40, 0, -1.35 } Should not impact the edge limit, at least when it comes to front and back edge limits. It should only impact left to right, which work fine.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.