Hello, i got my 2nd AMS using black friday discount and I already had to dismount it twice for a stuck filament. This so far happened with just one filament in two different slots (3 & 4 if that might matter) of the new AMS. In almost one year of printing with P1S and the old AMS this never happened.
The filament is a brown eSun PLA that has been opened months ago but has always printed ok (it did print ok last week after the first unclogging) and was always stored in sealed plastic bag with silica gel.
Now, as you can see in the following photo the filament seems to be very brittle
Wet/old filament can sometimes come back with a bit of heat treatment but I find it can be a losing battle if its like this. Running from the external would be my last resort as its less painful to clear out
It’s your $$, but in my opinion I’d aim for the bin.
I also have some old eSun filament that did the same, but it already did so in my previous printer’s bowden if left loaded for a couple of days without use.
I still use it in the AMS to not have to deal with the external spool but I take it out after printing.
Welcome to filament moisture. Starting at the “beginning”, fresh filament from the manufacturer can have a range of water contents. Don’t let the vacuum bag and desiccant it comes packed in fool you. With scales to weigh before and after and proper drying, new spools can give up 2-4g of water weight pretty easily. You usually can print with it to some degree fresh from the shipping bag but some like PETG HF can still show moisture issues straight from the bag.
If you used a Ziplock style bag, those are almost no barrier to water vapor. If you use a source of dry air to fill a Ziplock bag with a hygrometer in it then seal it up properly, the hygrometer will just about read ambient humidity in a couple of days. Very little protection from water with thin poly bags.
Last, the part about the silica gel - it can and does work both ways. It can absorb water but it can also provide water. Museums use silica gel “desiccant” to maintain humidity in display cases and such. For our purposes with filament, silica gel desiccant only helps keep filament dry if we keep the desiccant dryer than we want the filament. Best way to keep tabs I’ve found is with hygrometers in every container where I store filament. The hygrometers tell me the state of every silica gel sachet and filament spool in every filament poly box.
You may not have the same kind of water issues, though. Depends on the climate you see where you are. Many are in very dry climates so they don’t see the same kinds of moisture issues. Others are more borderline and do see moisture issues from time to time. That was my situation.
I used to keep filament in plastic bags until I saw how porous they were to moisture. Now it’s poly boxes with hygrometers and dry silica gel sachets. All my filament gets a dry air purge while drying in a filament dryer to a relative humidity in the filament dryer around 20% (depending on filament type) and then into a poly box where it pulls humidity below where the hygrometer can read (10%) as it cools.
But I needed to do all that for best printing and it can make a huge difference. Others may be in dryer or wetter climates and their needs will be different.
It’s my understanding brittle filament can come from moisture content and from drying at too high of temperature. Using dry air I dry a few degrees below stock temperatures for drying because the dry air lets me. You still need heat to get water off/out of the filament but can use a little less while staying far away from temperatures that cause brittleness. Being careful with drying and storage takes care of the moisture.
