Heater temp is off, way off.

tompoper

@aidar I was under the impression that M307 is what should be used to config the values recorded after running M303 H1 and recording the values.

aidar

Thats right, but see you config again, you apply these values to H0, not to H1.

From your first post :
M305 P1 T100000 B3950 C0 R4700
M307 H0 A549.1 C154.8 D6.8 B0

deckingman

@tompoper said in Heater temp is off, way off.:

@aidar I was under the impression that M307 is what should be used to config the values recorded after running M303 H1 and recording the values.

It is. But what you've posted is M307 H0 A549.1 C154.8 D6.8 B0. Note the "H0" - this should be H1.

Or to put it another way, you've tuned heater1 with M303 then put those values into config.g for heater 0.

Edit - was typing at the same time as @aidar

tompoper

@aidar Lol, I see what you are referring to. I checked, this is a typo in transposing the config line to the web. It does apply to H1 in my config.g.

deckingman

@tompoper The next thing to check is if you have a config-overide.g file and if so, does that have any values in it that differ from what you have in config.g.

A Former User

I have an ender 3 running a Duet Wifi.

below is my WORKING heater/thermistor settings.

; Heaters
M305 P0 T100000 B3800 C0 R4850 ; Set thermistor + ADC parameters for heater 0
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M305 P1 T100000 B4725 C7.060000e-8 R4350 ; Set thermistor + ADC parameters for heater 1
M143 H1 S290 ; Set temperature limit for heater 1 to 290C

dc42

@calvinx said in Heater temp is off, way off.:

I have an ender 3 running a Duet Wifi.

below is my WORKING heater/thermistor settings.

; Heaters
M305 P0 T100000 B3800 C0 R4850 ; Set thermistor + ADC parameters for heater 0
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M305 P1 T100000 B4725 C7.060000e-8 R4350 ; Set thermistor + ADC parameters for heater 1
M143 H1 S290 ; Set temperature limit for heater 1 to 290C

Why are you using R4850 and R4350 instead of R4700 (the correct value for a Duet WiFi/Ethernet)? If it's to try to get a more accurate reading at room temperature, you should be aware that changing the R value will probably make is a lot less accurate at printing temperatures - unless the Ender 3 thermistors have a very wide R25 tolerance and a narrow beta value tolerance.

A Former User

@dc42

I tried using the originals as is accepted in the docs and the temps would fluctuate wildly, those values stabilized everything and the web interface temps match what my external tests using my fluke thermocoupler gets.

It works for me, and prints fine but if its not suitable for others, don't use it.

Veti

@tompoper said in Heater temp is off, way off.:

3950

the generic B3950 +/- 1% thermistors are somewhat problematic.
the B3950 refers to the range of 25 to 50. They behave quite differently at temperatures around 200.
i had the same problem and i just replaced it with a pt1000 and its been very accurate.

If you actually calculate the values for a B3950 from the datasheet (if you are lucky that you get one)
like https://www.tinytronics.nl/shop/index.php?route=product/attachmanager/getfile&product_attach_file_id=552
and use the 220C value you will actually get a Beta value of 4171.
And if you put in 25C, 50C and 220C you get β: 4666 K C : 1.072208e-7

tompoper

@calvinx thanks for the info. Ill try all but the R value, as I understand it thats the resistance value for the board, if not please let me know.

tompoper

@veti I think an upgrade is in order to my thermistor. The ender 3 was a good starting printer, but my eyes have been opened as to why a more expensive printer is worth the money.

Veti

@tompoper said in Heater temp is off, way off.:

printer

Check out Triangelab. They sell quite high quality component at reasonable prices.
https://www.aliexpress.com/store/product/1PCS-trianglelab-ATC-Semitec-104GT-2-104NT-4-R025H42G-Thermistor-Cartridge-for-E3D-V6-Volcano-Sensor/1654223_32843785247.html?spm=2114.12010612.8148356.30.711e22f4czKlsU