Ender-3 V3 Plus X carriage for Coprint Chromahead

I thought there was room for improvement on the Creality/Coprint multicolor kit. The Chromahead mounted on the stock carriage sticks out quite far and in combination with the assymetric nozzle placement it reduces the print area from 300x300 mm to 290x283 mm.

This model offsets the head by 13 mmm to the right and 17 mm to the rear resulting in a 300x300 mm usable print area.

I also noticed the bed mesh is a bit flatter due to the x-axis not bending as much during probing in the center area.

To get clearance in the top the CX-I extruder mount hooks and KCM mount needs to be moved from the front of the top gantry. My KCM mount with cable management is one alternative.

Print settings

PETG 0.2 mm layer height, 3-4 walls, 20-25% infill.

I used conditional scarf joints to try and get the bearing holes as smooth as possible. I don't know if it makes a difference.
 

Assembly

Requires 6 M3 heat set inserts in the carriage block.

All other screws and nuts as well as the linear bearings and spring needed can be reused from the original Chromahead kit or the original tool head.

It is important to make sure the top right screw of the tool head does not stick out of the back of the connector plate. If it does it might collide with the gantry when the print head travels to the far right. Use a couple of left over washers or a M3 nut if needed.

The two belt mounts threads directly into the plastic. I couldn't figure out a better way to do it.

Service Tutorial Ender 3 V3 Replace the X axis linear bearing and copper sleeve
 

Configuration

You will need to change the following values in the respective sections in printer.cfg to reflect the change in position of the print head. Original value #commented out

[prtouch_v2]
clr_noz_start_y: 299 #280
[stepper_x]
position_endstop: -5 #-16
position_min: -5 #-18
position_max:300 #290
[stepper_y]
position_endstop: -10 #-28
position_min: -10 #-30
position_max: 301 #283

Optionally find the _CO_PRINT_DRAW_LINE macro definition in gcode_macro.cfg and change the following lines to get the nozzle prime line to print outside the print area.

[gcode_macro _CO_PRINT_DRAW_LINE]
       # Original G1 X2 Y210 Z0.4 F900
       G1 X-3 Y210 Z0.4 F900

   # Original G1 Y2 E20 F900
   G1 Y-3.5 E20 F900
   
   # Original G1 Y4 F900
   G1 Y-2 F900
   
   # Original G1 X4 E30 F900
   G1 X-1 E30 F900</code></pre><h4>Testing</h4><p>After assembly make sure the tool head moves freely along the x and y axis. Also check that the connector plate and 8-in-1 module does not collide with the gantry. On my Ender-3 V3 Plus the clearance is about 1,5 mm.</p><p>Before doing any printing, test your configuration changes by moving the tool head in small increments to the end stops one axis at a time.</p><p>Dont't forget to run a new input shaping and bed mesh calibration.</p>