I’m running TPU for AMS on stock settings on what was a .4mm nozzle and is now a .6mm nozzle. On the .4 this turns into a hard clog and on the .6mm it’s one that occasionally needing a pulling assistance a the AMS.
Looks like it getting too much heat maybe??? anyone know how to solve this?
Would love to print w/ a .4mm nozzle, but that’s out for the moment.
Picture shown is of the filament where I assisted the printer by pulling on it.
Just got done with a hard clog. It’s running again, but for how long??
Did you try drying it? I have a roll but haven’t opened it yet. I saw on the product page it says, “Dry before use”.
I’m having the same issue, but only when trying to do multi filament prints. I have dried mine and still having the issue. It seems to be an issue with the nozzle temp from the prior filament (petg cf) super frustrating. So far tpu for ams seems kinda pointless if it cannot be used for multi filament prints
Are you two printing with the door and top open? I think its easy to get tricked into thinking “I haven’t needed to open it in the past”, but if you are closed up and experiencing clogging, try opening and see if it helps.
I also just got my first roll of TPU for AMS and have not been able to do anything with it because of clogging. I don’t understand why would it be issue with nozzle temp because it is always monitored but apparently it is. I would think that if it just waits for a bit longer to cool the nozzle between filament changes it would solve this issue - would it? Is the some hack how to try this? Maybe modifying the gcode somehow…
Clogging is largely a situation where the filament softens up and deforms in the upper end of the hotend. When this happens, it can leave the extruder’s filament path or simply gum up the extruder. The softening of the filament is almost always due to the filament being too warm from the ambient temps in the printer. This is why Bambu suggests removing the top and opening the door.
If you have higher nozzle temps, you could have an increased possibility of the softening I mentioned. This occurs because the hotend has a hot side and a cold side, but both are fully connected with only a fan and heat sink managing the temps for the cold side. Conversely, the hot side is fully managed with the software and heater. So, if you have warm ambient temps (summer), a closed off printer, and higher than normal nozzle temps, clogging could definitely get away from you.
Consider this, the hot side gets up to around 220C where the fan and heatsink has to keep the cold side under 50C. Also note, the hot and cold side is only 50mm apart at the widest… basically, managing almost 170C difference in temps is just a tough job for a small fan and a heatsink.
I had troubles with the .4 nozzle, .6 nozzle works better. My problem with it is that I can’t get supports to release with the TPU for AMS.
Supports and TPU don’t go together very well. TPU forms too good of a bond to release easily. This generally gets worse with larger nozzles (more surface area to bond to the previous layer). One thing you can try to aid with that is to increase the distance of the support. There are 3 distances that I would consider critical.
The first and the one I play with the most, Object X/Y distance which basically sets the distance between the support and the object. If this is too close, the support will bond too tightly to the object and will be difficult to remove. If it is too far, the supports can’t do their job. I believe the useable range is somewhere between the default .35mm and 1mm. More than 1mm isn’t really useful, but any higher than default can cause issues when the object has support near angles. For me 0.5mm is my goto, and I pretty much default to that, and only stop using it when the object has an angled wall (which artificially creates a problem with that distance). On the angled wall is something you have to see to understand, but just remember angles cause the support to not generate when the number is too high.
The second is Top Z Distance. This dictates how much space is left between the object and the support interface. Less space will give a better finish but will be bonded too well and be hard to remove. More space is the opposite, worse finish and easier to remove. I suggest adding a 0.1mm at a time when trying to test. Also the same problem I mentioned above occurs when you have larger nozzles. Larger nozzles = harder to remove supports.
The final one is the Bottom Z Distance. This one I rarely change because it requires you to use supports on the model’s surface. This is rare because you have to enable that all by itself, so most people don’t use it because it not enabled. But it works on the same ideas as Top Z Distance.
All of this and much more is available on this page with illustrations, Support settings
I’m having the exact same issue with the red in my P2S with ams 2. The black and green Bambu TPU work great, but for some reason I’ve never been able to even start a print with the red. Is trying with the door open the way to go?
