So Im dusting off the snapmaker to do a bit of printing and want to print at 260deg…
I’m still on an old stable firmware and loathed to upgrade but probbably should. Can anyone confirm if the massive offset in temparature between commanded and what actually is via IR calibrated thermal imager has been fixed.
For example, when i command 260deg i actually get 220. Its been discussed many times before and the error has been compounded due to the fact that i have thermally pasted my thermocoulpes into the heater block. From factory the were just loose!!
If so which firmware is the least likley to FUBAR everything…
So short answer, taking a leap of faith with latest V1.14.1 firmware., is NO. its not been fixed. Demanded 240degC… get 239 on the controller and 203 on a recently calibrated fluke thermal imaging gun… grr… Yes if I could command 320degC say i might get the 240 to 250 i want but the firmware limits max temp to 275degC
Note this is possibly only an issue if you have secured your thermistor into the heater block with thermal compound
Oh the voltage divider reference is screwed then. Calculating the updated look up table values by assuming a different voltage divider circuit is theoretically pretty simple.
I’m inclined to agree with @brent113 and think that it’s a hardware problem specific to that particular print head. The most straightforward solution is warranty replacement.
Interesting as it happend on the head before i had erm… cough… an accident with the tool lead going in the wrong way round. Had to get head and main control board replaced. Still does it with this head.
I narrowed it down i thought to the fact I had pushed the thermistor much further in the heater block and thermal pasted it in. whereas before it was effectively underreading when just floating in air in the hole in the heater block.
Im gonna undo the thermal paste on one hot end and see if it changes
A partially shorted thermistor will appear as hotter, so yea maybe the paste you used is leaking current.
This is the table the firmware was developed around you can test the values and also measure the 4.7k voltage divider on the PCB if you want to test that
good info… so just tested my thermistor at room temp and 100deg C
Room temp about as expected at 125kOhms
But boiling water so pretty much 100degC at sea level is 9.9kOhms which is around 88degC. so possibly worth me replacing with a differnt brand / better tolerance NTC100k thermistor
So still no joy… replaced with thermistor with different brand and tried to heat to 275degC maximum I could get is 235deg C on the fluke IR thermometer but snapmaker reports 275degC. So defo take you up on the offer of a custom firmware with the ability to alter thermostat coefficients and do PID autotune
Use these for Testing or Development purposes. NEVER for production machine.
998 : Dummy Table that ALWAYS reads 25°C or the temperature defined below.
999 : Dummy Table that ALWAYS reads 100°C or the temperature defined below.
:{ ‘0’: “Not used”, ‘1’:“100k / 4.7k - EPCOS”, ‘2’:“200k / 4.7k - ATC Semitec 204GT-2”, ‘3’:“Mendel-parts / 4.7k”, ‘4’:“10k !! do not use for a hotend. Bad resolution at high temp. !!”, ‘5’:“100K / 4.7k - ATC Semitec 104GT-2 (Used in ParCan & J-Head)”, ‘501’:“100K Zonestar (Tronxy X3A)”, ‘6’:“100k / 4.7k EPCOS - Not as accurate as Table 1”, ‘7’:“100k / 4.7k Honeywell 135-104LAG-J01”, ‘8’:“100k / 4.7k 0603 SMD Vishay NTCS0603E3104FXT”, ‘9’:“100k / 4.7k GE Sensing AL03006-58.2K-97-G1”, ‘10’:“100k / 4.7k RS 198-961”, ‘11’:“100k / 4.7k beta 3950 1%”, ‘12’:“100k / 4.7k 0603 SMD Vishay NTCS0603E3104FXT (calibrated for Makibox hot bed)”, ‘13’:“100k Hisens 3950 1% up to 300°C for hotend 'Simple ONE ’ & hotend ‘All In ONE’”, ‘20’:“PT100 (Ultimainboard V2.x)”, ‘51’:“100k / 1k - EPCOS”, ‘52’:“200k / 1k - ATC Semitec 204GT-2”, ‘55’:“100k / 1k - ATC Semitec 104GT-2 (Used in ParCan & J-Head)”, ‘60’:“100k Maker’s Tool Works Kapton Bed Thermistor beta=3950”, ‘61’:“100k Formbot / Vivedino 3950 350C thermistor 4.7k pullup”, ‘66’:“Dyze Design 4.7M High Temperature thermistor”, ‘67’:“Slice Engineering 450C High Temperature thermistor”, ‘70’:“the 100K thermistor found in the bq Hephestos 2”, ‘71’:“100k / 4.7k Honeywell 135-104LAF-J01”, ‘147’:“Pt100 / 4.7k”, ‘1047’:“Pt1000 / 4.7k”, ‘110’:“Pt100 / 1k (non-standard)”, ‘1010’:“Pt1000 / 1k (non standard)”, ‘-4’:“Thermocouple + AD8495”, ‘-3’:“Thermocouple + MAX31855 (only for sensor 0)”, ‘-2’:“Thermocouple + MAX6675 (only for sensor 0)”, ‘-1’:“Thermocouple + AD595”,‘998’:“Dummy 1”, ‘999’:“Dummy 2” }
*/ #define TEMP_SENSOR_0 1 #define TEMP_SENSOR_1 0 #define TEMP_SENSOR_2 0 #define TEMP_SENSOR_3 0 #define TEMP_SENSOR_4 0 #define TEMP_SENSOR_5 0 #define TEMP_SENSOR_BED 1 #define TEMP_SENSOR_CHAMBER 0 #define CHAMBER_HEATER_PIN -1 // On/off pin for enclosure heating system
Configuration.h line 411 onwards for Max hotend temp
// Above this temperature the heater will be switched off.
// This can protect components from overheating, but NOT from shorts and failures.
// (Use MINTEMP for thermistor short/failure protection.) #define HEATER_0_MAXTEMP 290 #define HEATER_1_MAXTEMP 275 #define HEATER_2_MAXTEMP 275 #define HEATER_3_MAXTEMP 275 #define HEATER_4_MAXTEMP 275 #define HEATER_5_MAXTEMP 275 #define BED_MAXTEMP 130 #define CHAMBER_MAXTEMP 100
