I thought I would try out the PAHT-CF filament, but it has been problematic.
I was able to get two good prints, one out of each nozzle.
I ran the first print in the left nozzle (.4mm) and it printed great, beautiful print. Started the second print and the nozzle began to under extrude and I eventually had to abort the print.
In a hurry, I swapped the filament to the right nozzle. Second print came out beautifully. Then the next print started under extruding and failed. I tried to clean the nozzles but even with other filaments, I was getting extrusion problems.
Fine, I fowled two nozzles. I should have had dedicated ones for this material anyway.
New nozzles seems to have the right extruder working properly, but the left one is a no go. It now refuses to load filament. I put in new (larger) nozzles and it still fails to load the filament each time. It looks like the extruder wheel is spinning the wrong direction.
I took the extruder entirely apart and cleaned it (3 times now) with no change.
I tried disconnecting the AMS on the left extruder and attempted to manually load filament, but the extruder wheel doesn’t spin at all when I do that. In both cases, I can see the end of the filament makes it to the extruder gear fine, but the printer just wont crank it in there. With the AMS, it reverses immediately and so wont load. On manually loading, it just sits there, doesn’t spin, and then keeps asking me if the filament is extruding yet?. Of course its not extruding, its just sitting there doing nothing.
Update: Now the right extruder is under extruding again, so I am completely at a loss. I don’t even know what to try. Brand new nozzles, completely cleaned the extruder. And the filament is barely dribbling out of the extruder.
What did this PAHT-CF do to my perfectly functioning printer?
Update to the update. Now neither the left or right extruder will load filament. The AMS pushes the filament all the way to the gear, then retracts it. it repeats this a few times and then throws an error saying it failed to load and or extrude filament.
Double and triple checked it when I was only trouble shooting the left side only. But of course now that the right extruder, which was working for a bit, is now in the same state, there is no doubt the tubes are in the correct position. Otherwise I wouldn’t have been printing in the first place.
I found the problem. The gear that drives the filament has come loose from the shaft that connects it to the drive gear. This thing was just glued on! which makes sense why it failed when I was printing higher temperature filament.
I hope they have fixed this obvious engineering flaw. My printer was the first batch when they dropped the H2D printers so maybe this has been fixed.
Not sure where you’re located, but a defect like that would be considered a warranty case where I live. Bambu Lab cannot waive that responsibility in any agreement, so even if it’s a minor cost, I would still point out that it’s something they are obliged to cover.