I print with PS1 in my garage where its at least 100 if not 110. (I live in AZ) I print PLA in it all the time with the door open, and it prints fine. 110F is only 43C and PLA has no problem. Now I had another problem when the fan stopped, but that is another problem.
I hadn’t thought that this could be the issue, but after doing a bit of research, I looked into P1S heat creep. What I found were two types of spacers. One goes on the hotend, so that the small fan isn’t sitting directly against the heatsink near the nozzle, and from several videos, it seems to work. The other one attaches to the printer and creates some distance between the AMS and the rest of the printer.
The videos also showed the exact same problems I’m experiencing filament getting stuck in the extruder and/or in the hotend, air prints, etc.
As for the temperatures, since I’m from Romania, we’ve had temperatures as high as 40°C around 38–40°C and the printer is in a 3m × 3m room. I’m going to try this hack and print two Benchys, one with the spacer and one without it, and maybe something small and multicolored as well.
Chamber temp is more relevant than ambient temp, but usually the higher ambient temp, the higher chamber temp you are going to get. PLA will start to show these issues when the chamber gets around 45 to 50C. Before printing any spacers, I would simply open the doors and remove the top glass.
I guess what I am really getting at is if your 40C temperatures are higher than normal? What event happened two months ago to make these issues arrive?
The chances of having two identical failures in the machines at the same time is 1 in a million. That’s why it is better to look at environmental factors and inputs like the filament, temperature, and humidity.
I’m not familiar with the FilaDryer S2 but those temperatures are lower than generally recommended and 4-6 hours is probably too short. I dry PLA at 55C for around 8 hours but my endpoint is my dryer hitting 19% RH in the dryer at drying temperature. I purge my dryer with dry air which speeds that up a lot.
Also, new filament is generally not dry and frequently is not dry enough to print well. The vacuum bag is permeable to water vapor and water leaks in. That bag of desiccant in there is just an attempt to keep the filament dry. If a spool has spent a fair amount of time on a ship or sat somewhere for a while, it could easily have picked up too much water. New filament isn’t usually dry.
Low relative humidity is important for filament storage. If you are storing in a pantry, how is the humidity? Since you didn’t mention plastic bins or cereal boxes, I’m guessing it’s open storage with filament exposed to ambient air. That can work for some who have low ambient humidity but many find that they have print problems until they can store filament in more dry conditions.
Filament behaves like a weak desiccant. It absorbs water out of the air until it equilibrates with ambient humidity. My ambient humidity tends to run around 40-45% RH. My filament would pick up water until I started seeing moisture issues in my prints. I had to up my drying and storage games to get back to good prints.
I use humidity measurements a lot to keep track of my filament. I store spools in plastic cereal boxes with a desiccant pack and a hygrometer to keep it dry and know it’s dry. In storage, unless there’s a leak, my filaments are all stored at below 10% RH at room temperature. I don’t have clogs, zits, or other print issues that water causes - and water issues manifest in all sorts of ways probably because there are so many filament formulations. But water issues are known to wreak havoc on printing.
Especially with two printers behaving the same way, odds are low both would fail or fall out of adjustment at the same time with the same symptoms unless you did the same things to both printers. Possible but not sure how likely. Things like firmware/software updates could provoke the same problems in both printers but you didn’t mention that. The only other thing common to both printers is the filament and how you prep it / treat it before printing.
I am having a similar problem in that the print starts out good and after some time it appears the nozzle gets clogged and then it continues “air printing.” Below I’ll describe my setup and then some things I have attempted.
SETUP:
P1S, AMS Gen 1, AMS HT, SUNLU FilaDryer SP2.
BAMBU LABS TPU 90A.
Using default settings for “BAMBU LAB TPU 90A @BBLX1C” and “0.2mm Standard @BBLX1C” except as noted here and in the sequence of events below.
- Strength - Wall Loops changed from 2-4.
- Support - Enable support changed to on and set to default for attempt 1, Tree slim for attempt 2, andTree Organic 3.
- First and second attempts are with the original nozzle and gears. Third attempt is with the hardened gear and nozzle.
- First attempt with the P1S enclosed. Second and Third attempts are with the door all the way open.
Videos and pictures referred to below can be found here. In one of the pictures I put all three attempts on the bed just to show the different finish states.
The print is basically an arch. The usage for it will be to protect the front of an AMA on a sailboat.
Sequence of events and changes:
- Dried in the AMS HT for at least 4 days (probably 6) before attempting to print.
- First attempt (video_2026-08-27_04-42-12.avi) filament loaded in AMS HT through TPU port directly into the coupler on the back of the printer. In IMG_1187.JPEG this is the left most tower.
- Switched to printing PETG and PLA Silk.
- Printed SUNLU FilaDryer S4 Stand in PETG by Benjamin Kott (Thanks Benjamin! - you’ve got a like and Boost coming your way) to raise the dryer so that it goes directly from the dryer port into the coupler.
- Performed 3 cold pulls using PETG before setting back up for TPU.
- Changed the Retraction Length to 1.0 and 1.2 from 0.8. With these I could not get the first layer to print.
- Second attempt (video_2026-08-30_23-21-32.avi), filament moved to FilaDryer and dried for another 3 days. Raised the FilaDryer. and connected it directly to the coupler. This attempt is the middle (both in position and height) one in IMG_1187.JPEG.
- Dried for another day.
- Moved the filament to the external spool and fed directly into the tube on the back of the printer (no coupler). Started printing within a couple of minutes. Notice that the print was moved to the front of the plate to reduce the bend internal to the P1S. The other change was to "Recommended Nozzle Temperature to 220-240, originally 200-240) This is the right hand print in IMG_1187.JPEG and the only print in AMG_1186.JPEG.
I know there is still some stringing, but I can not believe it is because the filament is wet. By the third attempt the spool had been in a dryer continuously for 8-10 days. The FilaDryer was reading RH at 10%.
So, what should I try next?
As an aside, I’m going to try to salvage the third attempt. I figured out the layer that it stopped printing (779), and have sliced the model there and will just print that top part and manually glue them together. Someone will have to be looking for this to find it.
TIA!
What’s your chamber temeprature like? Could it be getting hot enough to cause heat creep and stop filament from being fed into the hotend?
Make sure your hotend fan is spinning properly, and try a print with the door open.
Feeling a little stupid. Didn’t think to set the nozzle to the hardened steel until just now.
Thanks for the response. I’ve been printing with the door open. I saw where heat buildup is/can be a problem for both PETG and TPU. That’s what allowed my PETG prints to finish.
The PETG was turning up at the corners. Eventually turned up enough that the extruder would hit them and knock the print across the plate or at least off of where it should be. They looked like this. Made some very cool, totally non functional designs. I guess I should have labeled them art and tried to sell them. 
If there is a silver lining, I should be able to do some very good bridging.
I’m experiencing the same exact thing with two of my P1S printers. Both have been working perfectly fine and now both are experiencing the same exact issues like you outlined in your post. Cannot seem to resolve the issue… tried rolling back firmware.. re-updated.. bought new hot ends… waiting for a new filament sensor cable to come.. switched out the filament brands.. tried printing from an external spool.. tried different prints… nothing yet.
Did you sort the problem out? You haven’t posted in a few days; I am hoping that means it is resolved! If not…
Is this the first summer these printers have been used? Is it the first time they have run in these temperatures? If so, consider that as the temperature increases, so does the water vapor capacity of the air. That will even leak into a pantry or cupboard that isn’t vapor-tight.
My theory is that even though you are drying the filament, it may live in such a challenging environment that even 6-8 hours is not enough. I would test this by trying to dry a roll for 24 hours at the highest temperature the filament can handle. (For PLA, that’s usually 45º, but check the recommendations of the filament manufacturer to confirm; sometimes it’s limited to 40º.)
How are you drying your filament?
Nah, I didn’t find any solution, even without the door and the glass on top I’m experiencing the same problems. At this point… I’m kinda done trying anything, maybe in the future I’ll change them with the newest model or I’ll switch to another brand. But I’m checking the topic every day to see some new opinions.
Later update, I changed ALL the PTEF tubes (including the AMS) and now it’s working, idk how but it works. 