My AMS HT arrived today and I had a chance to test it with PPA and PPS. With a few workarounds I was able to feed both of them from AMS HT regular feed (not the bypass hole) leaving the external spool dedicated for TPU only use like I hoped. Main advantage vs the bypass hole is not having to mess around with PTFE tubes.
If you select Bambu PPA-CF or PPS-CF it will throw an error and say it is not compatible so you have to select Generic PPA/PPS. Also I made the filament path very smooth long arc but it still had a problem loading and got stuck in the PTFE tube on the last turn before the hot end as those filaments are too stiff. What I did is hit “load” before the print, and manually worked the buffer back and forth as it loaded to give it the tiny bit of help it needs.
You also need to checkmark “Skip AMS blacklist check” in Bambu Studio before initiating a print.
Just keep an eye on the tube in the buffer. It’s a little a curve and will wear out quickly with stiff abrasive filaments. Just try pushing a small length of filament through it by hand and you’ll see what I mean.
I just got done with a spool of ppa-cf. After loading it the second time I realized that going through the buffer applied much more tension than I thought it should have. Switched it to the tpu port.
It would be cool if we could connect a normal straight buffer, like the ones for the x1/p1, and use that with the ams ht through the tpu port.
Yes i always check on PTFE tubes as they wear out quick with CF filament. Ive changed the ones inside my AMS 1 multiple times due to wear, a few were split in half.
I knew I could not be the only one having trouble feeding PPA-CF. I finally found this thread. I was expecting to find one mentioning the P2S. The help files only mention other printers. So it looks like you guys have come to the same conclusion as me. That the top glass is too close to the extruder head and that makes the last turn into the extruder too tight for the AMS HT to push it through. The filament also likes to snag at every tube entrance in each connector. I finally noticed and understood when the PPA-CF web store product description says “All AMS Series NOT Compatible” it is a grammar error and should read either All AMS Series Feeders Are NOT Compatible or None of the AMS Series support automatic feeding. Bambu does real good at not having grammar errors but this one slipped through and the singular vs plural of that is easy to miss. Without the plural it implies that there is one that is compatible and looking though the help files I expected that to be the AMS HT.
The error message it throws on mine is also wrong. When I try to feed PPA-CF from my AMS HT I get the error “The filament currently loaded in the extruder does not support manual feeding.” This is wrong. It should read “The filament currently loaded in the AMS does not support automatic feeding” I know there is a bug reporting system but I don’t yet know how to use it and I wanted to add this to a searchable thread. Hopefully they will update their documentation.
This thread tells me that yes it only takes two spools to wear out the PTFE tubes and I should replace them on my only 3 week old P2S.
It appears that if you have a print that will take more than 2 hours the filament needs to be fed from a dry box so it does not absorb too much moisture during the print. You also need a high temperature dryer. The AMS HT can be both of those but it can’t auto feed it. I need to try the bypass port. Don’t know if I need to bypass the buffer. I was trying to do 5 to 20 hour prints. I actually succeeded a few times so I was even more confused when it all went pear shaped.
I also learned elsewhere that regular white PTFE tubes are probably not what I want and I need to get special low friction ones. I also may have worn out the inside of my filament buffer.
Another note. Drying the filament seems to set the curve on the spool or however it is positioned during drying. So if the end is held straight during drying it might help. The inner coils of the spool are harder to get through the tubing. I don’t know if the inner coils are better straight from the box before drying as I don’t have enough experience yet.
Should I start a new thread with all of this information. I will probably design and print a top lid riser for the P2S. Maybe someone else already has.
PPS. If you go from PPA-CF to PLA, the nozzle likes to clog because the PLA temp is not hot enough to push the left over PPA out. I plan on getting some extra hot ends and swapping for that change. I did find that in the wiki but not soon enough.
I’d say the best answer is to put the filament in the AMS-HT, feed the filament though the bypass, run the HT drying only mode, and use the TPU assist module to help feed it.
Keeps the filament dry, by preheating it there’s a bit more flexibility, and the module helps with feed issues.
