I am having an extrusion issue that I just can’t figure out. The image below shows the problem. Extreme stringing and problems with bits of filament. I have several more printers and the model in the image below prints just fine in the other machines (P1P and P1S). But on this particular P1P this is the result I get.
I have tried:
-replacing the nozzle
-replacing the extruder
-trying a different roll of filament
-making sure there is nothing impeding the filament feed
The strange thing is that when I load filament or manually extrude filament it appears to flow just fine. There is no extruder skipping etc. But when I print this model with a relatively fast speed (small diameter part) I can tell the extruder is skipping a little. Other prints do print better, but there are still problems.
I’m at a loss for what the solution to this is. The next step might be to replace the extruder motor but as far as I can tell it is working properly.
I appreciate your thoughts. It’s not the filament. This same spool of filament prints just fine in other P1Ps I have. As I mentioned the issue is with this particular P1P but the model and filament prints fine on other machines. I’ve just replaced the heating element to see if that makes any difference, although the old thermostat/heater reported the correct temperature and didn’t seem to fluctuate.
Good thought. But it should have been taken care of by the first hot end replacement so not surprising that there’s no change now. I also concur that it is unlikely to be the extruder motor from your report.
There have been very few reports of cable/connector/board issues but that could be further root causes which would not neccessarily have been addressed by your troubleshooting.
So I’d suggest running through the recommended maintenance, just to be sure, maybe do a factory reset (stranger things have happened) but also file a ticket in case you may need to replace the board.
The mystery deepens. At first I really thought replacing the thermistor and heating element solved the problem. The print started out much better and got much further along, but alas the problem came up again.
I’d try printing it on one of your other P1’s with a different roll of filament, then with the same filament. Just to be sure to rule out root causes.
Board replacement can be quite tricky and, if it is the same as for the X1, may require activation by Bambu support post-replacement. So you want to be sure before embarking on that. And maybe open a ticket beforehand.
I’ll open a ticket, although I HATE how slow they are with support.
I have already tried printing with a new roll of filament etc so I’m comfortable ruling all that out. I don’t know what else to do other than replace the extruder board and possible the TH board.
That toolhead has all kinds of gotcha’s you have to be aware of. That’s just one.
Have you had the toolhead apart?
If yes, take it apart when you are fresh and not frustrated, like in next morning for example. Reassemble it after you’ve taken a break from fighting the printer.
So now I’m not sure if there is really a “problem” at all. Long story short, I increased the nozzle temp by 10C (to 260C - PETG) and that pretty much eliminated the dragging and stringing. The reason I didn’t think to try this is because as mentioned before this model prints perfectly fine on other printers at the original temp (250C).
This issue also started fairly suddenly, so I still think there is some sort of an issue related to temperature regulation with this machine. Changing the nozzle, extruder, heating element/thermistor had no effect. Printing PETG at 260C is right at the higher limit for the filament I’m using (220-260C). The other thing I don’t like about the higher temp is that it prints more “shiny”.
So I’m not sure what’s happening, but at least for now increasing the temp seems to have helped.
This is why I’m so dumbfounded as to what the problem is. I have been printing with the same filament and the same settings for years on 3 P1Ps and 4 P1S printers and this particular P1P printer started printing badly just recently. It doesn’t make sense that increasing the nozzle temp by 10C would solve the issue when it printed fine before.
I wanted to update this thread with the possible resolution. Despite installing a new nozzle, extruder, and heating element, the problem persisted. But I noticed that the filament was pretty severely curling up as it came out of the nozzle. Normally I assume that means the flow is restricted somehow so I proceeded to clean out the nozzle with the recommended procedure. It was during that process that I discovered there was a little bit of broken PTFE tube at the place where the PTFE tube goes into the extruder, and I think that was impeding the filament. After cleaning that out and also the nozzle, prints have been fine so far. I can’t be 100% positive that was the problem, but so far so good.
