Extruder heater temp

ronnien59

I have an EPCOS 100K Thermistor that is sealed in a sleeve. My settings are:

M305 P1 R4700 T100000 B4388 ; Put your own H and/or L values here to set the first nozzle thermistor ADC correction
;M301 H1 P8.8 I0.562 D41.9 T0.3 S1.0 ( i have tried this one as well with the same results)
M307 H1 A280.4 C94 D6.8 B0
M143 H1 S290

When the heater heats up to temp I am actually 100 degrees less, that is my PanelDue and Web inter face read 220 but when i check the temp i am actually at 120 degrees C.
I am currently running however i must be at 260 C to melt PLA.

I have change wiring twice to see if that makes a difference and it did not same results

Can anyone help, i need to get this right.

dc42

At the very least you need to change the B value in the M305 command to suit the Epcos thermistor. Find its datasheet (it may be this one http://media.digikey.com/pdf/Data%20Sheets/Epcos%20PDFs/B57540.pdf)) and use the config tool at https://configurator.reprapfirmware.org/ to work out its B value, and optionally its C value too if you are using firmware 1.17.

ronnien59

@dc42:

At the very least you need to change the B vale in the M305 command to suit the Epcos thermistor. Find its datasheet (it may be this one http://media.digikey.com/pdf/Data%20Sheets/Epcos%20PDFs/B57540.pdf)) and use the config tool at https://configurator.reprapfirmware.org/ to work out its B value, and optionally its C value too if you are using firmware 1.17.

Thanks, I will apply the new settings and try that.