Hello! Can someone illustrate for me how the AMS2 Pro is used to dry filament?
With the X2D and combo AMS2 Pro connected together, no external power supply, printer idle. I start drying with 4x rolls of PETG-HF and do not check roll filament. I have the filaments each still inserted into the AMS feeders.
When starting drying, it runs for about 5 minutes and then just stops. Heats up a bit, but never fully reaches the default set point. No message or anything, just stops and goes back to default printer screen. Tried both from the printer itself and the Handy app with the same result. Power cycled the printer. Latest firmware installed (there is only one update so far).
Do I need to retract the filaments or am I missing something obvious? Will it not run if the humidity is below a certain %?
This is my first AMS2 (came from P1S AMS combo) so I am unsure of how it is supposed to function. But I am excited to not need to use an external dryer (hopefully).
if you only dry the Fillament the X2D should be able to supply enough Power to your AMS 2 Pro
this sounds like something may be defect with the AMS 2 Pro
i would contact Bambulab support to see if they know something or see if you can get your AMS 2 Pro replaced
Hi @mbrick — I can confirm it works correctly on my setup: AMS 2 Pro connected directly to the X2D, no external PSU, and drying runs to completion without issues.
A few things from my experience that might help you troubleshoot:
On retracting filaments: when you start drying, the AMS asks whether you want to unload the filaments (so the spools are unlocked and free to rotate). That option enables the spool-rotation feature during drying, which helps expose all surfaces of the filament evenly.
I personally skip that step — I run drying with the filaments still loaded into the feeders. It works fine, the cycle completes normally, just without spool rotation. So no, retracting is not strictly required.
My setup: I keep about 1 kg of silica gel in printed containers inside the AMS. As a nice side effect, running a drying cycle should also regenerate the silica gel to some extent (the heat drives moisture out of the beads as well), so it’s a two-for-one.
About your symptom (heats up, runs ~5 min, drops back to default screen with no message): that doesn’t match normal behavior on my unit. A full PETG-HF cycle should run for hours, not minutes, and the temperature should reach setpoint. If it consistently aborts silently after ~5 min on multiple attempts, with no error and no message, I’d lean toward what Christian_Huber said — sounds like a hardware fault on the AMS 2 Pro side (possibly the heater or a thermal sensor cutting off prematurely). Good call opening a support ticket.
One sanity check before you escalate further: can you confirm the AMS 2 Pro is sitting on the dedicated combo bracket / power connection to the X2D and not just daisy-chained via the regular AMS port? The X2D combo connection is what carries the extra power for the dryer function.
Ok, glad to hear you are running it with filaments still loaded. Thanks for the insight!!
Can you confirm what you mean by combo bracket vs regular AMS port?
I have the AMS2 connected directly to the buffer with the longer included 6 pin cable exactly as shown in the wiki here.
I did some more testing and it will stay running at the lowest temp setting of 45C but when I change it to PETG default of 65C it turns off, around 48C temp. Hmm.
Potentially nothing we can do to fix it but I appreciate the help.
Coming back with new data, because there’s something interesting going on.
First, on my “combo bracket” comment from earlier — ignore it, I was misremembering. You’re right, on the X2D combo there’s just the standard 6-pin connection between buffer and AMS 2 Pro as shown in the wiki, and that’s what I have too. So we can rule out wiring as the cause.
On the temperature behaviour — I ran another PETG-HF cycle to actually monitor it. With my filaments already at ~10% humidity, the chamber temperature stayed around 32 °C even after an hour, well below the 65 °C setpoint. That’s basically ambient temperature here, so the heater doesn’t seem to be doing much.
Looking at the Bambu Wiki drying function page, the AMS 2 Pro doesn’t run a simple “heat to setpoint” loop — it has actively controlled intake and exhaust ports that the firmware operates dynamically:
Chamber below target temp → ports closed, concentrated heating to ramp up
So the displayed temperature isn’t a pure setpoint, it’s the input to a closed-loop process whose actual goal is moisture removal. With humidity already low on my unit, the heater appears to barely activate — whether that’s intentional firmware behaviour or something off on my unit, I genuinely don’t know.
Your symptom is different from mine, though. I get a temperature that just doesn’t climb; you get a full silent abort back to the home screen after ~5 minutes. Those are different categories of issue. The silent abort with no error message at ~48 °C doesn’t seem explained by the damper logic.
For the record, on my unit the starting humidity is around 10% — if yours is significantly higher, that might be a relevant variable.
When your cycle finishes is there any sort of message or information or does it just return to the filament drying screen? How do you know it ran for the full cycle and did not stop early?
Interesting, this is completely different behavior than I am experiencing in terms of how the cycle is carried out. I can start the cycle and the humidity is around 7% and will reduce to 0-1%, but it still continues to slowly heat, before it fails around 45-49C.
I also tried replicating running it at 45C for the full cycle and it still does not finish. I think maybe it just takes longer to error out so I falsely thought it would complete.
I have captured a video for Bambu Support, which was not easy because the end time is not consistent. It took about 12 minutes before it stopped this time.
Sounds like you’ve got a faulty AMS 2 Pro. Mine (in combo with X2D) heats up and holds temp for a full drying cycle without issue. I just choose the filament (or temp + duration) from the printer’s screen and press go and it runs. FWIW I am doing so without filament loaded so the spools can rotate.
The people with drier not reaching a full 65c.., are you all running your X2D’s in low power mode? Mine does the same as well. Stays between 60-62c tops.
I am having the same issue and have a ticket open. Support said it’s an issue in the firmware and they are supposed to push a beta firmware for me to test. Oddly enough, I have three AMS 2 Pros, all are on the same firmware version but only one has the issue.
My X2D / Ams 2 is doing exactly the same thing, the drying cuts off after a few minutes. I contacted Bambu via online chat yesterday who advised their technical staff “will get in touch”.
I am using the cable that was included with the X2D combo.
Bambu support also responded to me with the same, that they will send a newer firmware to try. Waiting for a response after their holiday.
I’m not glad to see others having issues but find some comfort I am not the only person and that it may be widespread enough that Bambu can identify and fix the issue.
Hi, I have exactly the same issue. Brand new AMS and X2D, mot possible to run a complete dry cycle. I will open a support ticket at Bambu. Does anyone knows if the new firmware solves the issue? Thanks!
For me the Beta firmware has solved the problem that the drying cycle was stopped after few minutes without any error message or something like this . It was assigned for me after I opened a ticket for this problem.
. It was assigned for me after I opened a ticket for this problem.