Error when adding servo in printer.cfg

Ender Series Creality Ender-3 V3 KE/SE
1

Hi,

I want to add a second extruder to my Ender 3 Ve 3KE using an external usb board (Rumba). Stepper, thermistor, heater and fan are all working so far.

I’m trying to add a servo to select mechanically switch hotend. When I add the [servo my_servo]
ot printer.cfg, I get this error message:

Section 'servo my_servo' is not a valid config section

…and the printer fails to restart.

I suspect it has to do with the Klipper version distributed for this machine so I tried to manually update Klipper (by copying files). No success so far. Swapping files just brick the machine. It’s easy enough to flash the original firmware to unbrick it but I’m just back at square one…

Any help to successfully configure a servo on the Ender 3 V3 KE or to upgrade Klipper to the latest release would be greatly apreciated.

Cheers!

2

I have no idea how to add more stepper motors. You’ll need to root the machine to get full klipper, have a read of this thread, it might be of help.

3

Hello Bonfireman! I got root access. No worries there. Adding stepper motors is not a mystery for me. It requires adding hardware and config. I got that covered too and it’s working.

I’m trying to configure a servo motor to select mechanically which extruder is perpendicular to the build plate. It should be super straight forward according to the Klipper reference .cfg files. I’m trying to do the same thing an in the reference file sample-multi-extruder.cfg.

If I add the section :

Servo definition

[servo extruder_servo]
pin: -wathever the pin designation-

Like in that reference file, I get an error and the printer will reboot but will be in an error state, giving the error message I mentionned in my initial post.

4

The documentation is very clear and easy:

[servo]

Servos (one may define any number of sections with a “servo” prefix). The servos may be controlled using the SET_SERVO g-code command. For example: SET_SERVO SERVO=my_servo ANGLE=180

[servo my_servo]
pin:
#   PWM output pin controlling the servo. This parameter must be
#   provided.
#maximum_servo_angle: 180
#   The maximum angle (in degrees) that this servo can be set to. The
#   default is 180 degrees.
#minimum_pulse_width: 0.001
#   The minimum pulse width time (in seconds). This should correspond
#   with an angle of 0 degrees. The default is 0.001 seconds.
#maximum_pulse_width: 0.002
#   The maximum pulse width time (in seconds). This should correspond
#   with an angle of maximum_servo_angle. The default is 0.002
#   seconds.
#initial_angle:
#   Initial angle (in degrees) to set the servo to. The default is to
#   not send any signal at startup.
#initial_pulse_width:
#   Initial pulse width time (in seconds) to set the servo to. (This
#   is only valid if initial_angle is not set.) The default is to not
#   send any signal at startup.
5

I think that buying the “KE” (which stands for Klipper edition) means that I should have access to the full Klipper possibilities.

6

All my printers on Klipper are hobbled in some way. My sonic pad has more Klipper functions but not everything. My Qidi printers are missing bits and are a version or so behind latest. The V3KE seems to be the most hobbled.