It took me a few weeks of tinkering but everything seems to be working now ...
0) Watched Chris's basement videos
1) Upgraded my Creality CR6-SE 3D printer to Klipper
2) Familiarized myself with the Prusa slicer (was using Cura before)
3) Tested electronics on a breadboard then designed/had board built using KiCAD
4) Refactored mk4generator code to allow me to use Klipper macros (easier to tweak things)
5) Played with a bunch of Prusa settings, bought PTFE tube with 2.5mm ID (== less jams with poor tips)
6) Modified Arduino code to support a CUT command (needed due to bowden tube)
7) Added 20KG Servo to cut filament (tip-shaping was hit/miss), with 8V from a buck-convertor
All my files are available on github: https://github.com/antonioasaro/3DChameleon
One of my 1st multi-colour prints - a ukulele keychain
My first 3 colour print.
I was experiencing some "crosstalk" between T1 (bottom left input) and T2 (top right input).
That is, when T2 tried to load, T1 would slightly unload, messing up the print.
I reviewed the article below and then changed the T1 (== unloading) bearing cam from the original of +2.00/-0.25/red top right to +2.00/+0.25, red top left to add more space between T1 and the gears.
Worked great.
I created/uploaded a filament_select_test.gcode file to github.
I used it to rotate between the 3 colours to make sure the "crosstalk" issue was gone before attempting to run the 8hr clownfish print.
https://www.tinkercad.com/things/0JBXWmRAdxn-3dchameleon-mk3-tension-tuning-sliders