Adding a new post instead of adding to my old one. I'm still running into issues with my chameleon unloading filament after a certain point when switching colors. This results in failed prints due to filament being pushed completely out of the chameleon gears. You can see in the photos below it's almost always at the halfway point or after about 4-5 hours of printing. This isn't an issue when printing flat items like the signs below.
I have tried the following;
Adjusted tension sliders
Cleared chameleon from debris
Verified that the feed gears are aligned like mentioned in the previous post.
Made adjustments to gcode to verify it prints as intended.
Adjusted my filament roller (thought that the extra tension might be an issue)
Verified that I can get filament to feed and retract without issues.
Swapped colors to different ports to verify that it's not the filament causing issues.
Swapped out blue for a different color just to verify that its not the blue specifically causing this issue.
All of the above haven't resolved this issue unfortunately. This can be replicated each time I print something for more than about 4 hours. Each time I can verify that the filament has backed out completely from the chameleon. It usually backs out any of the colors I was using during that print. Any color not used remains in place. I haven't reprinted any of the Mk4 parts as it switches fine and works for small items.
As mentioned above, flat prints/low layer height prints never seem to run into this issue. All colors return to 1" before splitter like printing signs for example
I'm a bit stumped and not sure where to look at this point. Any ideas?
This sounds a bit like a problem I was having. Occasionally there was a simultaneous unload of a filament when a different filament was commanded to load. I tried the tension tuning route but after watching the Chris Riley assembly video I checked the whole device, specifically the position of the selector bearings on the plastic cam. The one furtherest from the stepper had worked its way down the shaft and I guess was jamming the stepper, not allowing it to reach the correct positions. I printed a couple of "retainers" one for each bearing to hold them in their correct positions and haven't had a mystery unload since.
My guess is that the filament is being backed out because there is still a little cross talk, most likely due to a bit of contamination that has fallen into the drive gears or a slightly too tight tension tuning slider. Normally, contamination will not cause this, but if it's a large block, it might. It can also be caused by filament that isn't within tolerances... usually the same type of issue... both can be fixed with a small adjustment to a +.25 tension tuning slider for just the color that is backing out.
Bill