Purge chute for Ender 3 v3 SE

EDIT 30th Aug 2026: Added TRUNK and CRASHBLOCK for testing on the Ender 3 v3 KE.

1. Replace the Trunk from the SE set with the provided one in case your hotend is higher than the SE.

2. Attach the crash-block on the top of the CR-touch as such:

-- End of EDIT

About

If you've made a PicoMMU for your Ender 3 v3 SE/KE, then you've noticed that it's hard to keep the footprint of the wipe-tower small enough. Also tired of having to manually set the flush volumes in Orca Slicer, when in reality, a fixed amount is necessary to purge what's left in the hot-end? Then this mod is for you!

It replaces the X end-stop to offer a truly mechanical wipe/catapult action. It should be compatible with SE with any shroud. As for the KE, some tweaking may be necessary for the wiper arm. Probably lowering it by few mm to fit the longer hot-end.

List of Materials

• 5x M2 inserts e.g. L3mm D3mm

• 2x M3 inserts e.g. L4mm D5mm

• 5x M2x6mm countersunk screws

• 2x M3x12mm screws (any)

• 0.5x6x30mm spring is best, but you can use small variations

• small section of a PTFE tube

• Aluminum tape to cover the hot spots

I recommend printing the pieces in the orientations they come in the STL file, but also, to split into objects and print by objects. No support is required except for the end-stop arm.

PETG for shear and heat resistance is recommended.

Slicer config

In OrcaSlicer, set your flush volumes automatically, flush multiplier to 0.1, and put this for filament change G-code:

 _SP_SET_PURGE PURGE=50.0

Klipper config

In the Klipper config of your PicoMMU, set the Filament cutter macro to home X axis after the cut. I also disabled restoring the toolhead position and instead used PicoMMU's parking mode.

[gcode_macro _SP_TIP_FORM]   ## Tip forming user macro called during the tip forming procedure  - Filament Cut Macros go here
.......
  G28 X              # <<<<<<<<========== Home X Axis, after filament cut
  {% if sp.use_park == 0 and sp.sidestep_amount > 0 and runout == 0 %}
  G0 {initial_pos} F{60 * approach_speed}
  {% endif %}
.......

# Park
variable_use_park: 1                # 0 disabled - park during filament changes or stay next to the purge tower
variable_park_purge: 1              # 0/1 - on/off - purge the required amount of filament for a color change calculated by the slicer and sent though _SP_SET_PURGE PURGE=[first_flush_volume] 
variable_purge_unload: 0            # mm - distance - distance of filament to purge before unloading the hotend - helps with tip forming - only when park_purge is enabled 
variable_park_x: -6                 # mm absolute - park x
variable_park_y: "Y"                # mm absolute - park y
variable_park_dz: 10                # mm delta park z hop
variable_park_z_speed: 20           # mm/s speed for park moves
variable_park_speed: 200            # mm/s speed for park moves
variable_park_accel: 8000           # mm2/s acceleration for park moves