Filament_motion_sensor not working with extruder_stepper

General Discussion
1

Basic Information:

Printer Model: Modded Ender 3 v2
MCU / Printerboard: Octopus v1.1
Host / SBC: Raspberry PI 4B
klippy.log

klippy.log (3.5 MB)

Describe your issue:

I’ve got 4 extruders connected to a single hotend. The first extruder is defined as an extruder object, and the others are defined as extruder_stepper objects. I’ve got some BTT smart filament sensors (v2) that I’d like to add to each extruder. The first one works fine, but when I try to add the second one I get this error:

Internal error during ready callback: 'PrinterExtruderStepper' object has no attribute 'find_past_position'

I saw a similar post from last May with a solution involving adding the missing find_past_position method to the PrinterExtruderStepper class. The author said they might submit a PR to add this fix to the code base, but it doesn’t look like this was done.

Is there a better way to configure filament motion sensors on extruder_stepper objects? Should the fix suggested in that post get committed and merged? Thanks in advance!

2

Unfortunately, the log file is missing the Klipper version and seems modified.
Regardless, the method exists in the mainline.
So, you probably have to update to a more recent release than the one you have.

d77928b17b klippy/kinematics/extruder.py (Kevin O'Connor  2021-02-22 21:38:33 -0500 257)     def find_past_position(self, print_time):
6627d036ac klippy/kinematics/extruder.py (Kevin O'Connor  2022-02-21 13:51:27 -0500 258)         if self.extruder_stepper is None:
6627d036ac klippy/kinematics/extruder.py (Kevin O'Connor  2022-02-21 13:51:27 -0500 259)             return 0.
ffbd2698fe klippy/kinematics/extruder.py (Kevin O'Connor  2022-01-11 14:21:57 -0500 260)         return self.extruder_stepper.find_past_position(print_time)

Hope that helps.

Ah, well, you probably right.
But it is strange, you do request the extruder, not the extruder_stepper

Hmmm.

Aaah, there is more then one filament_motion_sensor

3

Ah sorry, I was trying to focus the log on the error itself, here’s the unmodified log. As for the release being outdated, I’m on v0.12.0-159 which is admittedly a bit old, but the problem seems to be with the PrinterExtruderStepper class used by extruder_stepper (as opposed to the ExtruderStepper class you’ve referenced, which my first extruder uses without any issues). The source for the PrinterExtruderStepper class hasn’t been updated in 3 years so I’m wary of updating unless I know it’ll fix the problem.

klippy.log (3.5 MB)

1 Like
4

Haha yeah, the first filament_motion_sensor works like a charm, it’s the additional sensors that aren’t playing nicely.

5

Here’s the pertinent config, if it helps any:

# Extruder 0
# Driver = DRIVER4 / MOTOR4
# Heater = HE0
# Thermistor = T0
# Runout = DIAG4
[extruder]
max_extrude_only_distance: 450
max_extrude_cross_section: 2
step_pin: PF9
dir_pin: PF10
enable_pin: !PG2
microsteps: 16
rotation_distance: 22.725 # 22.748
nozzle_diameter: 0.800
filament_diameter: 1.750
heater_pin: PA2
sensor_pin:  PF4
sensor_type: EPCOS 100K B57560G104F
#control: pid
# tuned for stock hardware with 200 degree Celsius target
#pid_Kp: 28.22
#pid_Ki: 3.12
#pid_Kd: 63.77
min_temp: 0
max_temp: 240
# PLA 0.4mm nozzle = 0.6944
#pressure_advance: 0.6944

[tmc2209 extruder]
uart_pin: PF2
run_current: 0.800
stealthchop_threshold: 999999

[filament_switch_sensor runout_switch]
switch_pin: PG11

[filament_motion_sensor runout_encoder]
switch_pin: PG10
detection_length: 4
extruder: extruder

# Extruder 1
# Driver = DRIVER5 / MOTOR5
# Runout = DIAG5
[extruder_stepper extruder1]
extruder: # If blank, not synchronized
step_pin: PC13
dir_pin: PF0
enable_pin: !PF1
rotation_distance: 22.725 # 22.748
microsteps: 16

[tmc2209 extruder_stepper extruder1]
uart_pin: PE4
run_current: 0.800
stealthchop_threshold: 999999

[filament_switch_sensor runout_switch1]
switch_pin: PF6

[filament_motion_sensor runout_encoder1]
switch_pin: PF5
detection_length: 4
extruder: extruder_stepper extruder1

extruder is the first extruder motor, which is tied to runout_switch and runout_encoder and works without any problems. extruder1 is the second extruder motor, which is tied to runout_switch1 and runout_encoder1. The switch sensor is fine, but the motion sensor throws the error. If I use extruder: extruder1 then it complains that the config object doesn’t exist.

6

Yes, I can reproduce that locally, I look for what can be done.

This seems correct:

diff --git a/klippy/extras/extruder_stepper.py b/klippy/extras/extruder_stepper.py
index 4ac5289f8..79d4feef8 100644
--- a/klippy/extras/extruder_stepper.py
+++ b/klippy/extras/extruder_stepper.py
@@ -15,6 +15,10 @@ class PrinterExtruderStepper:
                                             self.handle_connect)
     def handle_connect(self):
         self.extruder_stepper.sync_to_extruder(self.extruder_name)
+    def find_past_position(self, print_time):
+        return self.extruder_stepper.find_past_position(print_time)
+    def sync_to_extruder(self, extruder_name):
+        return self.extruder_stepper.sync_to_extruder(extruder_name)
     def get_status(self, eventtime):
         return self.extruder_stepper.get_status(eventtime)

I will make an PR: extruder_stepper: define missing public methods methods by nefelim4ag · Pull Request #7032 · Klipper3d/klipper · GitHub

Thanks for the report.

1 Like
7

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