High temperature recorded on hotend without it being on - HELP!

So, I have my budashnozzle hot end.
I diligently installed it and changed the code to honeywell resister (7) for the thermister. Now Pronteface is reading temperature as 450+ whatever I change.

Picture is of proteface. The code below is showing 100k thermisters I am currently using to detect the hotend temperature. Both are located on the hotend just to prove the discrepancy in the measurements. 'Bed' is reading true ambient temperature on the hotend but 'Heater' reads this figure whatever I seem to change. I have changed the ramps board, the arduino, the thermistors (to the 100k ones and back), I have re-uploaded Marlin to the arduino.

It seems to me a software/programming issue but I just dont know what I need to change. Anyone out there to help? Many thanks for any thoughts.

This seems to be the last thing before I can calibrate and print, please help!
Regards,
Mark


//===========================================================================
//=============================Thermal Settings ============================
//===========================================================================
//
//--NORMAL IS 4.7kohm PULLUP!-- 1kohm pullup can be used on hotend sensor, using correct resistor and table
//
//// Temperature sensor settings:
// -2 is thermocouple with MAX6675 (only for sensor 0)
// -1 is thermocouple with AD595
// 0 is not used
// 1 is 100k thermistor - best choice for EPCOS 100k (4.7k pullup)
// 2 is 200k thermistor - ATC Semitec 204GT-2 (4.7k pullup)
// 3 is mendel-parts thermistor (4.7k pullup)
// 4 is 10k thermistor !! do not use it for a hotend. It gives bad resolution at high temp. !!
// 5 is 100K thermistor - ATC Semitec 104GT-2 (Used in ParCan) (4.7k pullup)
// 6 is 100k EPCOS - Not as accurate as table 1 (created using a fluke thermocouple) (4.7k pullup)
// 7 is 100k Honeywell thermistor 135-104LAG-J01 (4.7k pullup)
// 71 is 100k Honeywell thermistor 135-104LAF-J01 (4.7k pullup)
// 8 is 100k 0603 SMD Vishay NTCS0603E3104FXT (4.7k pullup)
// 9 is 100k GE Sensing AL03006-58.2K-97-G1 (4.7k pullup)
// 10 is 100k RS thermistor 198-961 (4.7k pullup)
// 60 is 100k Maker's Tool Works Kapton Bed Thermister
//
// 1k ohm pullup tables - This is not normal, you would have to have changed out your 4.7k for 1k
// (but gives greater accuracy and more stable PID)
// 51 is 100k thermistor - EPCOS (1k pullup)
// 52 is 200k thermistor - ATC Semitec 204GT-2 (1k pullup)
// 55 is 100k thermistor - ATC Semitec 104GT-2 (Used in ParCan) (1k pullup)

#define TEMP_SENSOR_1
#define TEMP_SENSOR_1 1
#define TEMP_SENSOR_2 1
#define TEMP_SENSOR_BED 1

// This makes temp sensor 1 a redundant sensor for sensor 0. If the temperatures difference between these sensors is to high the print will be aborted.
//#define TEMP_SENSOR_1_AS_REDUNDANT
#define MAX_REDUNDANT_TEMP_SENSOR_DIFF 10

// Actual temperature must be close to target for this long before M109 returns success
#define TEMP_RESIDENCY_TIME 10 // (seconds)
#define TEMP_HYSTERESIS 3 // (degC) range of +/- temperatures considered "close" to the target one
#define TEMP_WINDOW 1 // (degC) Window around target to start the residency timer x degC early.

// The minimal temperature defines the temperature below which the heater will not be enabled It is used
// to check that the wiring to the thermistor is not broken.
// Otherwise this would lead to the heater being powered on all the time.
#define HEATER_0_MINTEMP 5
#define HEATER_1_MINTEMP 5
#define HEATER_2_MINTEMP 5
#define BED_MINTEMP 5

// When temperature exceeds max temp, your heater will be switched off.
// This feature exists to protect your hotend from overheating accidentally, but *NOT* from thermistor short/failure!
// You should use MINTEMP for thermistor short/failure protection.
#define HEATER_0_MAXTEMP 275
#define HEATER_1_MAXTEMP 275
#define HEATER_2_MAXTEMP 275
#define BED_MAXTEMP 150

// If your bed has low resistance e.g. .6 ohm and throws the fuse you can duty cycle it to reduce the
// average current. The value should be an integer and the heat bed will be turned on for 1 interval of
// HEATER_BED_DUTY_CYCLE_DIVIDER intervals.
//#define HEATER_BED_DUTY_CYCLE_DIVIDER 4

// PID settings:
// Comment the following line to disable PID and enable bang-bang.
#define PIDTEMP
#define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
#define PID_MAX 255 // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
#ifdef PIDTEMP
//#define PID_DEBUG // Sends debug data to the serial port.
//#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
#define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
// is more then PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
#define PID_INTEGRAL_DRIVE_MAX 255 //limit for the integral term
#define K1 0.95 //smoothing factor within the PID
#define PID_dT ((16.0 * 8.0)/(F_CPU / 64.0 / 256.0)) //sampling period of the temperature routine

// If you are using a preconfigured hotend then you can use one of the value sets by uncommenting it
// Ultimaker
#define DEFAULT_Kp 22.2
#define DEFAULT_Ki 1.08
#define DEFAULT_Kd 114

// Makergear
// #define DEFAULT_Kp 7.0
// #define DEFAULT_Ki 0.1
// #define DEFAULT_Kd 12

// Mendel Parts V9 on 12V
// #define DEFAULT_Kp 63.0
// #define DEFAULT_Ki 2.25
// #define DEFAULT_Kd 440
#endif // PIDTEMP

// Bed Temperature Control
// Select PID or bang-bang with PIDTEMPBED. If bang-bang, BED_LIMIT_SWITCHING will enable hysteresis
//
// Uncomment this to enable PID on the bed. It uses the same frequency PWM as the extruder.
// If your PID_dT above is the default, and correct for your hardware/configuration, that means 7.689Hz,
// which is fine for driving a square wave into a resistive load and does not significantly impact you FET heating.
// This also works fine on a Fotek SSR-10DA Solid State Relay into a 250W heater.
// If your configuration is significantly different than this and you don't understand the issues involved, you probably
// shouldn't use bed PID until someone else verifies your hardware works.
// If this is enabled, find your own PID constants below.
//#define PIDTEMPBED
//
//#define BED_LIMIT_SWITCHING

// This sets the max power delivered to the bed, and replaces the HEATER_BED_DUTY_CYCLE_DIVIDER option.
// all forms of bed control obey this (PID, bang-bang, bang-bang with hysteresis)
// setting this to anything other than 255 enables a form of PWM to the bed just like HEATER_BED_DUTY_CYCLE_DIVIDER did,
// so you shouldn't use it unless you are OK with PWM on your bed. (see the comment on enabling PIDTEMPBED)
#define MAX_BED_POWER 255 // limits duty cycle to bed; 255=full current

#ifdef PIDTEMPBED
//120v 250W silicone heater into 4mm borosilicate (MendelMax 1.5+)
//from FOPDT model - kp=.39 Tp=405 Tdead=66, Tc set to 79.2, aggressive factor of .15 (vs .1, 1, 10)
#define DEFAULT_bedKp 10.00
#define DEFAULT_bedKi .023
#define DEFAULT_bedKd 305.4

//120v 250W silicone heater into 4mm borosilicate (MendelMax 1.5+)
//from pidautotune
// #define DEFAULT_bedKp 97.1
// #define DEFAULT_bedKi 1.41
// #define DEFAULT_bedKd 1675.16

// FIND YOUR OWN: "M303 E-1 C8 S90" to run autotune on the bed at 90 degreesC for 8 cycles.
#endif // PIDTEMPBED



//this prevents dangerous Extruder moves, i.e. if the temperature is under the limit
//can be software-disabled for whatever purposes by
#define PREVENT_DANGEROUS_EXTRUDE
//if PREVENT_DANGEROUS_EXTRUDE is on, you can still disable (uncomment) very long bits of extrusion separately.
#define PREVENT_LENGTHY_EXTRUDE

#define EXTRUDE_MINTEMP 170
#define EXTRUDE_MAXLENGTH (X_MAX_LENGTH+Y_MAX_LENGTH) //prevent extrusion of very large distances.

Edited 2 time(s). Last edit at 08/26/2013 11:18AM by kramma.

---

------------------------------------------------------------------------------------------------------------------------

Mendel Max
Arduino
Ramps 1.4
Marlin


...still yet to print!

Just for giggles, pull the hot end thermistor wires off of the ramps and measure the resistance between the two wires. This should come out the reistance of the thermistor (with a tiny bit added in for the wire that you probably won't even see).

Thanks for the suggestion - Done and they seem to be giving me the 100k figure i would expect - that said I was fairly sure of that being true as when i use them for the bed they seem to work fine!?
What is going on?!
K

Wait... the same thermistor works fine (= you get the correct reading) when used for heated bed? That's weird.

One thing I've noticed in your code is..

#define TEMP_SENSOR_1 
#define TEMP_SENSOR_1 1 
#define TEMP_SENSOR_2 1 
#define TEMP_SENSOR_BED 1

I think TEMP_SENSOR_0 values should be set to 7 or 71 since you said you have Honeywell thermistors. What even more weird is that you actually do not have any value there. Well, I just noticed that you have TEMP_SENSOR_1, in a place TEMP_SENSOR_0 is usually found. So, you got two definitions for constant TEMP_SENSOR_1.

Is this copy/paste error, or you are actually using TEMP_SENSOR_1 and/or TEMP_SENSOR_2 constants instead? If that's the case, I would still say 1 is not the right value.. but the again, as mentioned at the top if the same thermistor works fine when used for the bed.. then 1 was the right (close enough) value, since that's the value assigned to TEMP_SENSOR_BED.

So... I'm confused, too. LOL

Edited 2 time(s). Last edit at 08/26/2013 02:00PM by Yamster.

FYI or FWIW, this is what I have in my firmware:

#define TEMP_SENSOR_0 5
#define TEMP_SENSOR_1 0
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_BED 6

I have EPCOS thrmistor installed on my heated bed, and ATC Semitec thermistor in my hot end.

Yep, there's a long story behind it; I basically checked/double checked and replaced pretty much every components and parts in my hot end past few weeks, thanks to several jamming issues I had.

Edited 1 time(s). Last edit at 08/26/2013 02:04PM by Yamster.

I know I am starting to feel that I have replaced everything as well!

Here is another picture of things going weird - honeywell selected this time and 100k hotbed thermistor strapped to the hotend


Thanks for the enthusiasm to at least not make me feel im going too mad for not being able to spot the issue.

---

------------------------------------------------------------------------------------------------------------------------

Mendel Max
Arduino
Ramps 1.4
Marlin


...still yet to print!

Thanks for this must have been a cut copy error - sadly still didnt recitfy the issue!

So, now the hot end temperature reading is not consistent with that of the heated bed, but after updating the code to Honywell it's showing a value which is a lot more reasonable than before (51C instead of 495C), right?

Actually, judging from the fact that the temperature of the heated bed in your new picture is showing 92C, I think it was heated up before and now in process of cooling... and that means the hot end was also heated up and being cooled down. (Actually, I can see from the Pronterface log window that the hot end was heated up and then turned off before you took this picture)

In other words.. they may not need to be showing the same temperatures at that moment?

What are the temperature readings from hot end and heated bed when they are completely cooled down to the room temperature now? In my case, those two temperatures are often off by 1 or 2 degrees (most of time they are the same or off by one, while one of them flickering back and forth to the same temp as the other and one degree off). If your two temperatures are different with bigger margin, then one of them is probably wrong.

However, seeing your temp reading on the hot end going down from 495 C to 51 C, it makes me to believe we are on the right track. Maybe all you need is picking the right temperature table or fine tune the table yourself after all. Aren't there two different tables for Honeywell thermistor to choose from? Did you try the other one?

Yamster Wrote:
-------------------------------------------------------
> So, now the hot end temperature reading is not
> consistent with that of the heated bed, but after
> updating the code to Honywell it's showing a value
> which is a lot more reasonable than before (51C
> instead of 495C), right?

Yes, but still not close enough for me to be comfortable about reckoning on the true figure.

> Actually, judging from the fact that the
> temperature of the heated bed in your new picture
> is showing 92C, I think it was heated up before
> and now in process of cooling... and that means
> the hot end was also heated up and being cooled
> down. (Actually, I can see from the Pronterface
> log window that the hot end was heated up and then
> turned off before you took this picture)

It was but the values were very different

> In other words.. they may not need to be showing
> the same temperatures at that moment?
>
> What are the temperature readings from hot end and
> heated bed when they are completely cooled down to
> the room temperature now? In my case, those two
> temperatures are often off by 1 or 2 degrees (most
> of time they are the same or off by one, while one
> of them flickering back and forth to the same temp
> as the other and one degree off). If your two
> temperatures are different with bigger margin,
> then one of them is probably wrong.

The bed is 22-25oC , the heater zero

> However, seeing your temp reading on the hot end
> going down from 495 C to 51 C, it makes me to
> believe we are on the right track. Maybe all you
> need is picking the right temperature table or
> fine tune the table yourself after all. Aren't
> there two different tables for Honeywell
> thermistor to choose from? Did you try the other
> one?

Well... managed to produce some really sensible figures from programming the marlin sorfware to ramps board '34' (basically 2 extruders instead of one extruder and a fan). When I set everything up for my one extruder set as 'extruder 2' the thermistor works fine and is in agreement with the bed thermistor +/- 5oC.

Weird.

However when I went to print it said there were errors and I should correct the errors reset the printer - what error this was I just dont know

Will have a go this am and see what comes of it all.

As ever, thanks for the input

Have the same problem, done what i can.
#define TEMP_SENSOR_0 -1
#define TEMP_SENSOR_1 0
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_BED 0

Check if the voltage over the ntc when connected is 4.7 to 4.8V when heater is off, voltage drops when heating. If not, the board is faulty, if yes, check the pin.h configuration. thermistor Extruder1 should be on pin analog 13.

Edited 1 time(s). Last edit at 09/05/2015 05:57PM by imqqmi.

You might have a hardware problem. My printer would show 500c than shut off the extruder. It turns out that I had a intermittent short. Try measuring the resistance across your thermistor. It should be at 100k+-10k Ohms at room temperature. If it shows 20 or less ohm than you have a short. If the resistance is like 50ohm or 200 or something strange than you don't have the thermisitor that you think you do.