Prusa CORE One L nozzle wiper

Prusa CORE One L nozzle wiper to attach to the front right of the heatbed, holding a silicon Bambu Lab A1 nozzle wiper.

It’s attached to the front right to be where homing and purging happens to reduce travel time, and to avoid collisions at the front left with the automatic vent opener.

Print orientation

Print Prusa_CORE_One_L_nozzle_wiper.stl in its natural orientation with the nozzle wiper facing up. Supports are unnecessary but an outer brim prevents warping.

Materials

• ASA or PETG filament. While heat tolerance is desirable, the nozzle wiper model and printer start G-code edits are designed to avoid the printed plastic getting too close to the hot heatbed or nozzle.

• 1 × Silicon Bambu Lab A1 heatbed nozzle wiper, with adhesive.

• 1 × M3 5.7mm threaded heat set insert.

• 1 × M3 10mm screw. Because the screw is able to pass all the way through, most lengths >= 6mm will probably work.

Print settings

Prusa Slicer print settings preset 0.20mm STRUCTURAL @COREONEL, modified:

• Layers and perimeters

  • Vertical shells

    • Perimeters: 3

  • Quality

    • Avoid crossing perimeters: True

  • Only one perimeter

    • Single perimeter on top surfaces: All top surfaces

• Infill

  • Infill

    • Fill density: 25%

    • Fill pattern: Gyroid

• Skirt and brim

  • Brim

    • Brim width: 6

Assembly

1. Insert the smooth end of the heat set insert into the hole at the bottom of the model, and with a soldering iron, press it all the way in so that it’s visible at the other side. The screw hole passes all the way through the model to accommodate a greater range of screw lengths.

2. Adhere the Bambu Lab A1 heatbed nozzle wiper to the top of the model.

3. Clip the assembled nozzle wiper to the front right of the heatbed.

4. Screw it to the heatbed carriage from the bottom.

5. Edit the printer start G-code (see below).

Printer start G-code

In Prusa Slicer, for the Prusa CORE One L physical printer settings, edit the start G-code to:

1. Add nozzle wiping (with a printer screen message “Nozzle wiping”) before the normal nozzle cleaning that happens prior to bed probing. The wiping sequence starts at the closest corner of the wiper to where homing occurred to reduce travel time, and drags the nozzle several times diagonally across the silicon bristles for effective cleaning. This removes many of the strings or blobs that cause nozzle cleaning failures. The normal nozzle cleaning is still useful because it ensures the tip is flat and clean prior to bed probing; if it’s not, you want it to fail.

2. Change where the nozzle waits to reach first layer temperature, to above the nozzle wiping start position. The move is slow to reduce noise and stress, while there is plenty of heating wait time to utilize.

3. Add another nozzle wiping (with a printer screen message “Nozzle wiping”) after the nozzle reaches first layer temperature. This wiping has a better chance of removing filament stuck to the nozzle when it’s at the filament’s melting temperature.

4. Quickly move the nozzle to a new purge start position that’s to the left of the nozzle wiper, and a little further towards the front of the build plate than usual to avoid the initial purge line sometimes falling onto the plate instead of neatly hanging.

At the start, insert the nozzle wiping config variables:

; Nozzle wiping config
{
  global wipe_x1 = 298;
  global wipe_y1 = -8;
  global wipe_x2 = 268;
  global wipe_y2 = -4;
  global wipe_z = 1;
  global wipe_speed = 10000;
}

If you are using a nozzle that protrudes lower than a regular Prusa brass CHT nozzle, to avoid it pressing down too far on the silicon bristles during wiping, increase the variable wipe_z from 1 to something like 1.5.

Then, before:

G29 P9 X208 Y-2.5 W32 H4

Insert:

; Nozzle wiping
M117 Nozzle wiping
G0 X{wipe_x1} Y{wipe_y1} Z{wipe_z} F{wipe_speed}
G0 X{wipe_x2} Y{wipe_y2} Z{wipe_z}
G0 X{wipe_x1} Y{wipe_y1} Z{wipe_z}
G0 X{wipe_x2} Y{wipe_y2} Z{wipe_z}
G0 X{wipe_x1} Y{wipe_y1} Z{wipe_z}
G0 X{wipe_x2} Y{wipe_y2} Z{wipe_z}
G0 X{wipe_x1} Y{wipe_y1} Z{wipe_z}

Then, replace:

G0 X249 Y-2.5 Z15 F4800 ; move away and ready for the purge

With:

; Move to above the nozzle wiping start position
G0 X{wipe_x1} Y{wipe_y1} Z8 F4800

Then, after:

M109 S{first_layer_temperature[0]}

Insert:

; Nozzle wiping
M117 Nozzle wiping
G0 X{wipe_x1} Y{wipe_y1} Z{wipe_z} F{wipe_speed}
G0 X{wipe_x2} Y{wipe_y2} Z{wipe_z}
G0 X{wipe_x1} Y{wipe_y1} Z{wipe_z}
G0 X{wipe_x2} Y{wipe_y2} Z{wipe_z}
G0 X{wipe_x1} Y{wipe_y1} Z{wipe_z}
G0 X{wipe_x2} Y{wipe_y2} Z{wipe_z}
G0 X{wipe_x1} Y{wipe_y1} Z{wipe_z}

; Move to the purge start position
G0 X255 Y-8 Z15 F10000