Temperature stability with MicroSwiss hot end

Hi all.
I recently equipped my second CR 10-S Pro V2 with a Micro Swiiss hot end.
It worked well after I found the correct printng temperature for my filament.
For another part I needed to change filament, so I first decided, to find the correct printing temperature, using a temperature tower.
During the test, a block occured. After fixing this I wanted to run the test again, but now the temperature of the hot end wouldn’t stabelize. I tried a manual heating of the hot end and the same thing occured.
The temperature keeps swinging around the set temperature.
Can anyone help me fix this?

Have you tried doing a PID tune?

Through either octoprint, or pronterface (both would need a connection to your printer which i can dig deeper if needed)

Tell the printer to do an M303 e0 s215 c9

What this is doing is

M303 = PID autotune, so it tell the printer to go to the set temperature.

E0 = the heater number, im assuming you only have 1 hotend, though you could do different numbers depending on your printer. If its stick id stay with E0.

S215 = set temperature. I picked 215 beacuse thats been my average temperature for pla thats been pretty good for me. Id say it wouldnt hurt to run with this, or whatever youve found usually is a good temperature. Assuming your doing PLA id say this wouldnt be a bad base to start with. Next time you do a PID tune, insert your magic number you found that works best from your temp tower.

C9 = the number of cycles. Since a PID tune takes the average, i like odd numbers. Most people so 8, or 10. You could do 1, and i think there is a max limit, so id go with something between 6-10.

Thinking more about it, there may be a PID tune setting in your printer already aswell. Look under the settings. Id check mine but its currently printing for the next 19 hours.

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Also, my cr10 s pro v1 came used with a mocroswiss, though it wasnt set up correctly and had a blob. Not your issue, but since i went back to stock, id say double check the ptfe tube is inserted correctly (i know its an all metal hotend, but dosent hurt)

Also also, your hotend static temperature reads ambient correctly, which should be about the same as your bed when its cold.

Thank you for the tip. I’m gojng to give it a try immediatly.

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Let me know if it helps or not.

If you do the pid tune manually, you will likley have to change the current PID numbers with those new ones, and then save it.

I forget the m5xx numbers but here is a link i pulled from google.

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I’ve run the auto PID tuning and changed the PID settings.
As the temperature is still wobbling, I ran it again and at the end it tells me to set new valuse for DEFAULT_Kp _Ki and _Kd in the Configuration.h file. As this is a seperate Marlin file, it needs to be downloaded to the printer, I think. Am I correct and if so, how do I do so?

Technically yes, but i wouldnt be jumping to a configuration.h modification for something like this.

How are you doing your PID tune? Also when its done it should give you some numbers, take a picture of them, or write them down.

I prettymuch follow the steps in here, with an added m503 step at the begining to see what numbers im getting first, and at the end to verify the new PID is saved.

When your PID is done, enter

M301 Pxx.xx Ixx.xx Dxx.xx with the x’s being your new numbers.

After that do m500 which saves it

Then I do an m503 which lets me verify myself that its saved, also so i can see other bits of data not related to the PID or temperatures, such as my esteps.

Though if you successfully do a PID and save it, and the temperature is still swinging, how much is it swinging? Is there a draft? Have a look at your hotend to be sure the fans are both running correctly and as intended. How is the wireing for the heater cartridge and mote importantly the thermister. (Note the heater cartridge should likley have the insulated red wires, while the thermister has the thin wires.)

Another question, have you gotten a thermal runaway message?

Check that the thermistor is inserted properly. Ideally, it should be snug against the heater block. If it is not stuck against the heater block, or if the thermistor has come out of its socket, the heat from the heater block will transfer to the thermistor much more slowly since that heat has to travel through air. That introduces a time delay between when the heater block reaches the trigger temperature (max to turn the heater off and min to turn the heater back on) and when the termistor actually measures it.

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Thanks for the thermistor tip. I refitted it and now the system seems stable. The temperature swings about 3 degrees either side of the set temperature, where before it was as much as 10 dergrees.

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