[BUG] ABL - Not Probing all the points

[psavva]

Bug Description

I have enabled Auto Bed Level Bilinear and found that not all points that are supposed to be probed are being probed.

I have a 7 x 7 mesh whish should probe 49 points (which is accurately displayed on the LCD), however, only the first row is being probed, ie: the 1st 7 points are being probed, and no more.

My Configurations

Configuration : https://github.com/psavva/Marlin/blob/9f935383099ec295145b53cfb9a3775854144dff/Marlin/Configuration.h
Configuration adv:
https://github.com/psavva/Marlin/blob/9f935383099ec295145b53cfb9a3775854144dff/Marlin/Configuration_adv.h

Steps to Reproduce

1. G28
2. G29

Expected behavior: Probing of all Points should occur

Actual behavior: Probing stops after the 1st 7 points.

Additional Information

https://youtu.be/cejU9yV6Aa0

[psavva]

I will also provide the following tomorrow:

• Download Marlin bugfix-2.0.x to test with the latest code.
• Enable DEBUG_LEVELING_FEATURE and M114_DETAIL and re-flash the firmware.
• Issue M111 S247 to enable maximum logging.
• Issue G28
• Issue G29
• Attach the log output into a .TXT file

[psavva]

I see that lots of changes made it into fac3a7d yesterday.
I will retest shortly based on the latest as of now, and report back with results

[psavva]

Debug Info after latest update and enabling debug_leveling_feature, and m1114_detail, with maximum logging enabled

G29-Probes 7 out of 49 only - debug info.TXT

[psavva]

I have noticed this in the log:
08:12:33.887 : Error:Probing Failed

I think it's only returned by probe.cpp lines 709 - 731

float measured_z = NAN;
  if (!deploy()) measured_z = run_z_probe(sanity_check) + offset.z;
  if (!isnan(measured_z)) {
    const bool big_raise = raise_after == PROBE_PT_BIG_RAISE;
    if (big_raise || raise_after == PROBE_PT_RAISE)
      do_blocking_move_to_z(current_position.z + (big_raise ? 25 : Z_CLEARANCE_BETWEEN_PROBES), MMM_TO_MMS(Z_PROBE_SPEED_FAST));
    else if (raise_after == PROBE_PT_STOW)
      if (stow()) measured_z = NAN;   // Error on stow?

    if (verbose_level > 2) {
      SERIAL_ECHOPAIR_F("Bed X: ", LOGICAL_X_POSITION(rx), 3);
      SERIAL_ECHOPAIR_F(   " Y: ", LOGICAL_Y_POSITION(ry), 3);
      SERIAL_ECHOLNPAIR_F( " Z: ", measured_z, 3);
    }
  }

  feedrate_mm_s = old_feedrate_mm_s;

  if (isnan(measured_z)) {
    stow();
    LCD_MESSAGEPGM(MSG_LCD_PROBING_FAILED);
    SERIAL_ERROR_MSG(STR_ERR_PROBING_FAILED);
  }

Looks like I need to rerun the test with Verbosity Level set...
I will run G29 V4
Also looks like V parameter is undocumentd:
https://marlinfw.org/docs/gcode/G029-abl.html

[psavva]

This is the log with G29 V4
For Verbosity Logging

G29-Probes 7 out of 49 only - G29 V4 - debug info.TXT

[psavva]

This is the log with G29 V4 and
#define BLTOUCH_DELAY 500

G29-Probes 7 out of 49 only - G29 V4 -BLTOUCH_DELAY-500- debug info.TXT

[psavva]

As Another Test, I've disabled Multiple Probing:
//#define MULTIPLE_PROBING 2
//#define EXTRA_PROBING 1

Now Probing has completed all 49 Points.

Seems there is an issue with Extra Probing...?
G29-Probes 7 out of 49 only - G29 V4 -BLTOUCH_DELAY-500- debug info.TXT

Update: After trying to print from the SD Card, G28 Completed, but G29 again stopped on the 7th probe point.

Update2: Even from RepetierHost, I am now consistently failing on Point 7 with Error: Probing Failed. Also tried restarting the machine. Again, after G29 Failed on Point 7.

Seems once it passed, and again consistently failing on point 7 probe from the 7x7 grid.

[psavva]

Update: I've switched to UBL and for around 70 probe points, not one Probing Failure as reported by Bilinear Bed Leveling. Seems the issue can be narrowed down to other bed levelling systems...

[sjasonsmith]

The important line from your logs is this one:

13:55:08.413 : SLOW Probe fail! - Triggered early.

This is related to a sanity check that is a recent addition to Marlin. It attempts to detect unexpected early probes, and fails probing to avoid damaging your printer.

The behavior of this sanity check is influenced by Z_CLEARANCE_BETWEEN_PROBES . You could try increasing that value (perhaps from 5 to 10), to see if it makes your issues go away. If so, there may be an issue with that logic, or your bed may be very non-level, causing the probe to trigger much earlier than expected.

[psavva]

Does UBL not take Z_CLEARANCE_BETWEEN_PROBES into consideration?

UBL is working perfectly.

I will update Z_CLEARANCE_BETWEEN_PROBES to a higher value, but my bed is unlevel a maximum of 1 mm from the center. 400x400 bed

[boelle]

@psavva still an issue?

[psavva]

Hi @boelle

I believe that there is a bug here.
As I was not able to solve it, I've moved over to UBL which I'm happy with. Probing is working perfectly with UBL whereas probing fails using ABL...

Another user has faced this same issue and closed it as a duplicate based on the fact that this issue is open.

I recommend that one of the devs which understand the probing code better than I do review why probing fails under ABL but is just fine under UBL.

[boelle]

Please test the bugfix-2.0.x branch to see where it stands.

[boelle]

Lack of Activity
This issue is being closed due to lack of activity. If you have solved the
issue, please let us know how you solved it. If you haven't, please tell us
what else you've tried in the meantime, and possibly this issue will be
reopened.