We have two H2D printers, both have an AMS pro.
I have printed a set of descant containers and have about 150 gm of Alumina in all.
I see that slowly the humidity is getting worse. Today I triad to activate the AMS own drying mode without rotating. As we have both PLA and ASA at the same AMS I only set it to 45 C… To my surprise the humidity rose and not dropped ?
Anyone seen similar results ?
This is exactly why I say adding active drying feature for multi-spool AMS alike systems is a terrible idea. Why I’m super not impressed by both AMS 2 Pro and AMS HT. The heating feature is a joke.
The drying process itself is conflicting with “keeping the chamber dry”.
When you’re drying, the air valve opens from time to time, it’s supposed to release the internal humid air and balance with external air. However the problem is that maybe the external air is also wet. The AMS itself is not capable of drying the dehumidifiers, so that means, during the drying process, you’re constantly saturating your dehumidifiers. And once the dehumidifiers are saturated, your lowest reachable relative humidity level would be significantly higher than what you would be comfortable with.
Terrible idea, sadly that Bambu literally listened to the loud crowd. And I am pretty sure all the other manufacturers are gonna follow, even if this is a terrible idea.
Having both a standalone dryer, and a well sealed storage space, is much much better than a 2 in 1 that can’t do both well.
Bambu should outright just sell us a ADHS, Automatic De-Humidify System, that can hold 4 or more spools individually, and can heat up each spool individually… and can reach a high temp for prolonged period and seals well… Without the AMS capability to prevent it from being damaged from heat…
I see that all the time when starting drying a new filament spool. As the spool heats up water starts coming off and so the humidity rises. Without filament the relative humidity will actually fall as the air heats up.
I can’t say on the AMS2 but that stage where water comes off the filament wholesale can frequently be helped with a door prop on other filament dryers. Desiccants change that though as they just absorb and absorb.
When humidity rises in a filament dryer the water is coming off the filament faster than it can exit the dryer. That’s why the door prop helps. But it also connects the dryer to the larger room air so as the water comes off an open door eventually can stall the dry.
I was not sure about that but you convinced me… Thanks…
Just my experience here…
Because activated alumina releases moisture when heated at too low temperatures, while silica gel does not. At 45 °C the alumina begins to desorb the water it has absorbed, increasing the humidity, but silica gel remains stable and does not release moisture at that temperature.
However, it is more accurate to say that both materials release some moisture when heated, but activated alumina does so much more aggressively at lower temperatures. Silica gel releases moisture far more slowly at 45 °C, which is why the RH spike is noticeable with alumina but not with silica gel.
I have removed all the desiccant containers from the AMS and dried the Alumina in a separate oven.
I have activate the AMS drying and the humidity increased like a previous member wrote.
After about 2h of drying the Alumina I returned it into the AMS and the AMS now reports 12% humidity
Even still, if you put wet filament in a dryer and it starts to dry out, of course your humidity will rise. Only once the filament has actually dried will the humidity go down.
I think the drying works well, but I do think the units don’t seal as well as they used to. In the past I never thought the AMS was bad at sealing like I feel the new one is. However, I do want to say its possible the old AMS simply didn’t seal as well as we all thought it did. It was only giving us an icon that says things are good, or things are bad. Now, we are getting numerical data which is very easy to validate and infinitely easier to criticize.