Prusa MK4 setup help and new 3D Chameleon feeding problems.
I received my new 3D Chameleon on Friday last week.(2-9-24) I found https://www.printables.com/model/475335-prusa-mk4-mounts-for-the-3dchameleon-with-prusasli to print switch and get a profile for prusaslicer from the 3mf file. I have my switch set at 211 and have not been able to get a proper load and unload of filament. I have been looking through forum and found a few things like setting single extruder multimaterial parameters to all 0 and unchecked box for high current on filament swap. I normally don't inport profiles and not sure if it sets all parameters that are needed. I also do not know if the profile is setup for mode 2 or mode 3.
I tested that it homes, and loads and unloads with the. 5 to 2 seconds switch press. I believe its in mode 2. Then i installed the MMU on my MK4. I setup a square for each color to print 3 layers each. With all filament loaded 1" before Y adapter it would home but not load starting color, then it would attempt to load next color. I still need to adjust timeing for length of filament because it grinds a bit on loading to hotend. When i preload T0 to hotend it will print and atempt to load next filament but i need to tweak the Tool change G-code as I am having some trouble with tip shaping, but that does not enplane next issue.
The next issue i have is random filament feeding lengths. After some troubleshooting the brand new mmu i found the set screw that feeds T1 and T3 loose. Then cleaned filament out of gears and reinstalled everything. Before full install i tested that it would load and unload multiple times before putting Y adapter into my feedhead.
Test in Video
I load all filament to 1" before Y adapter.
I press switch to Home and load T0. (5th pulse) Filament looks to long.
I then press switch for T1. (2nd pulse) This unloads T0 just out of Y adapter and way short of making it back to 1" line
I then press switch for T0. (1st pulse) The same thing it unloads just past Y adapter and way short of 1" line.
I then go back and forth between T0 and T1. Each time it stays in Y adapter until T1 rubs T0 filament.
I'm not sure what i should try next to fix my issues but i would appreciate any help. All parts are new and unmodified besides the one time i disassembled and found loose set screw.
I can't see the video yet, but based on what you're describing, it's working 100% exactly as it should. In Mode 2, it always loads 11" but it only unloads 10". That's by design. The reason is simple, you're testing it without the extruder doing any of the movement of the filament. Normally, during a color change, the system will back out the filament out of the nozzle for tip shaping, then once it's cooled enough, it will back it all the way out of the extruder. At this point, the filament is just before the drive gears and is not gripped by the extruder. Then when you do a color change, the 3DChameleon will pull it out the remaining 10". However, when it goes to reload it, it will load it back that 10" + one additional inch, which is when both the 3DChameleon is pushing and the stock extruder is pulling it into the drive gears. If your timing is correct, that will load it about 1" into the extruder. From there, the 3DChameleon will let go and the stock extruder will load it the rest of the way to the hot end.
If your Y adapter is like mine in the Mk4 picture, you should be fine.
Bill