Almost have my 3d chameleon working and all setup but im having an issue with T2 not able to feed all the way. It seems to always get stuck or not have enough grip to push. T0, T1 and T3 work perfectly with the same filamant.
I have tried the tension tuner sliders to increase the presure on the filamant but havent had any luck so far.
There are a few things to check. 1) Is the drive gear in place? If it's not aligned correctly, it can cause the filament to ride on the smooth part of the shaft instead of the drive gears. 2) Is the grub screw on the drive gear tight... if it is loose, it will allow the drive gear to turn without it moving the filament.
3) Are the screws in the unit too tight? When it's on #2, where is the line of the selector pointed. If it's not exactly at the 3 o'clock position, then something else might be off. Too tight screws can flex the plastic and cause it to bind.
4) Are the springs in place... one extruder acting different than the others is a big clue here... it's possible the springs are not seated correctly... or, even more likely, there are slight tollerance differnces causing that cam to not push the bearing into the filament far enough. You can adjust the tension tuning sliders, like you mentioned, but which one did you change to? There are to variations... one changes the spring tension, and the other changes the bearing position. In your case, you need the one that changes the bearing position closer to the drive gear.
5) If you have an older unit, it's possible you have some printed parts that are out of spec... when you take it apart, are the parts labeld A, B & C, or A+, B+ and C+? If they're not the + parts, it's advisable that you reprint those parts to our current + ones. They have a much better tollerance stack and prevent that exact issue. You can find them on Printables here: https://www.printables.com/model/354998-3dchameleon-mk4-upgrade-parts-with-ptfe-grip
Bill
A lot of us have a similar problem. I finally fixed my by getting a Prusa XL with 5 heads.