[3D Touch & Klipper] - Probe not coming down Randomly during Bed Mesh

General Discussion
1

Basic Information:

Printer Model: Longer LK1
MCU / Printerboard: Original 32bit Board
klippy.log → Included
klippy (1).log (963.5 KB)

Describe your issue:

Hello everyone,I have a Longer LK1 which I converted to Klipper. I’ve been trying to make it work with 3d Touch (TriangleLabs latest version) but not successfully.

I wired it with a 10k resistor, followin this post by Longer: Tutorial of BLTouch for LONGER LK1/LK4/LK4 PRO/LK5 PRO Leveling

Funnily enough longer mentions a 10k resistor in the picture, but on the text they mention 100k. I’m currently using the 10k resistor. Didn’t tried with 100k because I don’t have any.

I configured ABL, X Y Z offsets, did the sanity checks, home and all was going well. When I tried to do my first Bed Mesh I noticed that the probe wouldn’t come down randomly. Meaning, I’d home, then I’d hit “calibrate” to generate the first mesh, probe would come down on the first touch and then wouldn’t come down on the second, making the nozzle to go down to the bed. This will happen either at the first probing, sometimes at the 5th, others at 10th… Absolutely randomly. Funnily enough, the Home ALWAYS works. I also tried the Probe Accuracy test, and sometimes he’d finish the test, others it’d happen the same problem during the test…

I went through the klipper documentation, tried using both the “probe with touch” and the “stow on each probe” without improvements.

I also tried to change the control_pin from !PD13 to PD13 → With this, the probe doesn’t come down when homing and got the error “BLTouch failed to verify sensor”

I also tried to add the ^ in the sensor pin → It can home but fails similarly as explained above.

I have no ideas where to start to look for. I tried googling and seeing other people’s with same problem but to no avail.

2

Here is the short version of the printer.cfg with interesting sections for ABL:

[stepper_z]
step_pin: PE0
dir_pin: !PB9
enable_pin: !PE1
microsteps: 16
rotation_distance: 8
endstop_pin: probe:z_virtual_endstop
#position_endstop: 0.0
position_max: 400
position_min: -6

[bltouch]
sensor_pin: PE6
control_pin: !PD13
x_offset: 56
y_offset: -16
samples: 2
speed: 2
sample_retract_dist: 3.5 
samples_tolerance: .3 
samples_tolerance_retries: 3 
#z_offset: 0.0

[bed_mesh]
speed: 100
horizontal_move_z: 5
mesh_min: 56, 19
mesh_max: 296, 284
probe_count: 5,5
mesh_pps: 2,2
fade_start: 1
fade_end: 10
fade_target: 0

[safe_z_home]
home_xy_position: 125, 125 # Change coordinates to the center of your print bed
speed: 50
z_hop: 10                 # Move up 10mm
z_hop_speed: 5

#*# <---------------------- SAVE_CONFIG ---------------------->
#*# DO NOT EDIT THIS BLOCK OR BELOW. The contents are auto-generated.
#*#
#*# [stepper_z]
#*# position_endstop = +0.005
#*#
#*# [bltouch]
#*# z_offset = 2.430
3

Here is a video of the issue happening:

4

Please put code snippets between Preformatted text tags:
image

This makes it easier to read and saves space on this page.

5

Thank you, eddited to make it more readable!

1 Like
6

See BL-Touch - Klipper documentation

7

Thank you for the link. I had been all over that documentation over the last two days, and only when i exhausted all the options I saw there, I decided to bother other people here! :frowning:

8

Did you experiment with the settings that are mentioned in the “Clone” chapter? From your klippy.log it does not look like.

From your log:

probe accuracy results: maximum 11.240000, minimum 6.017500, range 5.222500, average 9.203750, median 9.865000, standard deviation 1.801210

There is more wrong than only not deploying. The accuracy is roughly a factor 362 worse than it is expected. No setting will influence this

9

Thanks a lot for the input. I don’t know why it’s not in the log, but indeed I played with “probe with touch” and the “stow on each probe” without improvements.

Regarding the accuracy, it’s just because I was using the finger instead of the bed, to avoid crashing, and I don’t have surgeon hands :smiley: That’s why the value fluctuates that much!

10

Well, apart from this:

  • Triple check wiring
  • Try a different sensor port

If this does not help, then maybe the 3D Touch has a defect.

11

Thank you for the suggestions. I redid the wiring (before I was using a servo plug) and I re-wired it for a normal port 3 wire plug to make sure there was no bad contact.

The fails still continue.

How I would go about trying a different sensor port? My motherboard only has this one 3-pin port, no other. So i guess in my case I couldn’t try another, right?

12

I am not familiar with this board. The information about it seems sparse.

You could use a free Endstop pin.

13

I’m sorry if this is too dumb, but from what I can see and understand, the endstop pin is just 2 wires, while this BLTouch has 3 wires, so how would I go about wiring it?

Would I have to wire GND + SGN (With pull up connection to 5V from somewhere else)?

14

The two relevant pins are only the sensor pin (most relevant / white cable) and the control pin (orange pin).

I would start trying to relocate the sensor pin to another pin on the board. Also inspect your board if any of these pins have some significant capacitors attached (> 100 nF) to the sensor pin. Such pins must be avoided since they “confuse” the timing.

15

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.