I was having a heck of a time trying to do my 4-color 3dchameleon install on my Ender3 V2 using the "classic" method, where the chameleon extruder simply loads the filament into the primary ender3 extruder, but the primary extruder is what is used during printing. I decided that eliminating the primary extruder and using the 3dchameleon as loader/unloader AND extruder was just going to simplify everything from the gcode to having one less step to go wrong. I followed this video (linked from the FAQ):
I think I've finally got my gcode figured out, and I'm able to successfully load and unload a single color (lets say extruder 2). Unfortunately, I noticed that when I use the same gcode on extruder 1, the extruder is moving in reverse.. which probably makes sense since one of the gears is on the opposite side. I realize I could just swap the extruder instructions in my load/unload by swapping positives and negatives, but that won't help during the actual printing where I might be switching between colors during print. How would I be able to have the extruder direction "inversed" for 2 of the 4 gears, using the above configuration?
Bill responded directly to one of my questions about extruder loading problems and noted that using the 3Dchameleon mk2 as the extruder is quite the headache.
As such, I wasn't going to go down that path but I did have a thought for your situation. If you were to want to reverse the direction of specific extruder I wonder if setting the steps/mm to a negative number in the extruder start/stop gcode would work in that instance? Not sure... and I'm sure it's not recommended. Maybe something like
M92 E-93.0; set to -93.0 steps per mm (extruder moves in the reverse sense????)
Then go back the other way with:
M92 E93.0; set to +93.0 steps per mm (moves in the normal sense?)
I've not tried it myself so I don't know if negative numbers are accepted, nor do I know how well it would work (guess this is a bit of a thought experiment and not backed by actual data). I think the bearings used in the 3Dchameleon to pinch the filament may hold with different strength and slipping might be more of a factor when trying to control filament flow with high precision?