I have been having an issue on all 3 P1S printers that I use. Currently, I have to run them all without any cooling, whether it be part cooling or auxiliary cooling. The reason for this is whenever cooling is turned on, the nozzle temperature plummets immediately, leading to an error about Abnormal Nozzle Temperatures.
The Temperature drops to 0 degrees, and any information online says this is an indication of broken thermistor or heater wires, which I do not believe. While testing for this issue, I would start a print and let it run for an hour or so, and I would have no issues. I would then turn on all the fans, and the temperature would drop to the point where it faults. The nozzle will then drop to 0 degrees.
The interesting part about this is if you turn off the fans and resume the print, the temp value shoots up from zero to its actual value, so it seems the thermistor is working properly.
This has happened with brand new hotends on their very first print, so unless I am receiving bad hardware (I hope not, they are directly from Bambu’s shop), I believe this to be an issue with how the heaters compensate for a drop in temperatures in the software.
I am running the printers with stock speeds and the silicone sleeve is on the nozzle. I am applying thermal paste to the heater as well as the thermistor each time. I have attached a link to a video showing this problem
The hot end is weak on high temps. Some have modified the hot end with dual 48 watt heaters or used a cht nozzle with the aftermarket hot end it can help but the Bambu heater is still the weak link unless you mod it with dual heaters or go with the BIQU panda 60 watt hot end coming out soon or the new E3D / Bambu hot end might be a option.
Ya what happens when the nozzle heater can not keep it in temperature range it shuts off and will go to zero as a fail safe as you have already noticed.
It seems very strange why Bambu would have a product that has issues within their allowed operating ranges. Why would they let me print at temps so high that a heater cannot keep up with the cooling they provide? Why is there a heater on this printer that cannot keep up with fans at max speed? It seems they have done their homework when designing these, so why is this happening?
It also seems like nobody else has this issue which to me, is very confusing. I will definitely be looking at those hotends when they are released.
They were all running the latest version (1.05.02) when the problem started, so I downgraded them to v1.04 see if it was a firmware issue, and it somewhat helped for a period of time, but the issue came back. Currently, I have one printer at the latest version and the other two are at 1.04, and they all have this problem.
Yep it’s sad and they did not do good high temperature homework that’s why they most likely reached out to E3D for a hot end solution and the aftermarket is also working on 60 watt hot ends.
I found the same problem as you. Even petg Bambu has overhang fan speed @ 90% if you put it to 100% the hot end will drop nozzle temp some.
Do you run PETG with cooling often? I’ve resorted to just turn all fans off, but if you have good cooling settings, I’d be inclined to try again. Curious as to what temp you run it as well. I have found with the speeds I have to max the temp, and if I turn on ludicrous mode the print has a matte finish because it is flowing so quickly.
I just started having this same issue but on the A1. It happens even when printing at 230 degrees. As soon as the fans kick on, the temperature plummets. This wasn’t an issue even a week ago and I didn’t update the firmware. Curious to see what you find
Sorry to hear you are having the same issue. It seems like it is just us having this problem.
What fan speeds are you running?
I have had a bit of luck just dropping the temp by 10 or so degrees, but I have been printing on the higher end of the temperatures, around 270 with PLA.
I have my fan settings below, hopefully they can help you. Granted I am using a P1s, but maybe it’ll be useful for you.
One thing that has seemed to fix this issue was replacing the TH board. I am able to run max part and auxiliary fans at max speed without the temperature from dropping. This printer is running PLA at 270 as well.
I have heard that these boards were replaced in newer printers, but I cant verify that. I wonder if these printers have the old board, as they were purchased through a third party (Microcenter) and it could be possible these were part of the old stock with the ‘bad’ boards.
Again, I cannot verify if this actually happened, all I know is that replacing the board has allowed me to utilize the fans fully.
