Poor heating performance with Mosquito Magnum

Poor heating performance with Mosquito Magnum

I recently contacted support about this issue, but the responses are taking days, and I am getting very frustrated with this issue.

Below is my original message to the support team.

"I am running Klipper on a BTT SKR1.4 Turbo, and I am unable to get my mosquito magnum to reach and maintain temperature.  The heater cartridge as well as the thermocouple are both installed using the boron nitride thermal paste, and the heater is powered through a solid state relay which is connected to a 12VDC - 30Amp power supply via 10AWG wiring.  I also verified that the heater cartridge that I ordered is 12VDC as it should be.

I have attached a picture of the installation of the hot end as well as a documented chart from octopi.  In the picture, you will see that the part cooling fan blows just below the nozzle, but even though it is only a 40x10 fan, and doesn't blow directly on the block, I cannot maintain a temperature over 250C while running the fan at 100%.  Even at 250C, it can barely do it without feeding any filament (See attached chart).

My first thought was that the power supply wasn't able to keep up, however there were no differences in the performance whether I was running only the hot end by itself, or when I had motors powered on and also with the heat bed set to 70C at the same time.  During prints at 100mm/sec, the filament running through the hot end is also enough for the temperature to start dropping without a fan at 275-285C.  Measuring voltage on the power supply while trying to heat up the hot end shows a solid 12VDC.

Since I first ordered and installed my mosquito, I have been printing successfully up until the last week when I got my part cooling fan installed.  I did notice that I was starting to have problems printing at higher speeds after making some other modifications to my printer that allowed me to start printing more than 100mm/sec, but I was limited mostly by the part cooling, now that I am trying to use the part cooling fan, I can't print at all because it seems like the heater cartridge just heat the block very well.

Thank you in advance for your help with this matter."

The only reply that I have received since posting this 5 days ago asked me to measure my RTD PT1000 thermocouple's resistance at room temperature, and what my settings were in Klipper for the PT1000.

The PT1000 is reading roughly 1.1k ohms which appears to be correct after looking at the resistance table.
My sensor configuration from the [extruder] section in Klipper:
heater_pin: P2.7
sensor_type: PT1000
pullup_resistor : 4700
sensor_pin: P0.24
control: pid
pid_Kp=32.634 
pid_Ki=2.112 
pid_Kd=126.049
min_temp: 0
max_temp: 350 

I just pulled my heater cartridge and the PT1000 and then reinstalled them just to be sure that the Boron Nitride paste had completely filled any possible gaps in the block, and it looked perfect.  I tried to calibrate the PID once again afterwards, but I still have the same issue.  Even with the fan off, I can't calibrate at 325 without it failing.  As soon as the calibration tries to drop the temp 5 degrees, it never manages to recover.

Brian