Marlin Temperature Automatically Rises

Hi,

I am trying to get my hot end to heat up with ramps and stay at a constant temperature. However in Marlin the hot end resistor will automatically start heating and I have measured 12v on the D10 connector of the ramps board. The thermistor shows the correct temperature of the hot end and it goes to about 100-150C before lowering back to ambient. It does this when i power the board and not when I have told it to start heating etc.

Looking through the forums I have found that a common problem is that the D10 mosfet is shorted and applies 12v all the time. I replaced the fet and tested again, still no dice! After getting a bit frustrated I tried loading sprinter and low and behold the temperature works fine! It shows the correct room temperate and then when I press heat to 185C in pronterface it heats and stays at the set temperature!!

Does anyone know why this is happening and how I could fix it in marlin? I have everything set up correctly in Marlin and don't want to use sprinter if possible.

Thanks, Jack

Edited 1 time(s). Last edit at 08/12/2013 10:51AM by JackDavies.

Hi,

Could you upload your Configuration.h file? > (Attach a file, Choose, Attach).
Which hot end are you using?

Hi,

Thanks for your quick reply.

I am using a modified scratch built ultimaker hot end.

Config file is attached.

Kind regards, Jack

Try to uncomment #define PIDTEMP

// PID settings:
// Comment the following line to disable PID and enable bang-bang.
//#define PIDTEMP

Hi,

I have tried that but nothing changes. It is strange because its working fine with sprinter and marlin being based quite heavily on sprinter I can't seam to find what's wrong!!

Any other ideas?


Thanks

... I would try with motherboard=33, just to see what happens.

When did you download the Marlin-Firmware? They change the source code almost every day.

I also found this which is the same symptoms as me!

[forums.reprap.org]

I downloaded it yesterday evening, the motherboard settings again has no impact. Would it be something to do with the PID Bang Bang settings?

Jack

one more idea:

Download Marlin here:

https://github.com/ordbot/Marlin


I tested this version with my Hadron Printer.
You can replace Configuration.h with yours.

Edited 1 time(s). Last edit at 08/12/2013 01:13PM by flurin.

That's great, I will try it when I get back home.

Thanks for your help

I tried the different firmware but nothing changed.

This is getting stranger! I changed the preconfigured code for selecting the hot end to the Makergear one to see what would happen. It started of looking good as it stayed at ambient room temperature, I then did the het to 50C in pronterface and it got there and stayed constant for about 5 seconds. Unfortunately it then dropped back down to about 30C again!! I have attached the temp graphs from Pronterface. I really want to get this working!

// 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

JackDavies Wrote:
-------------------------------------------------------
> ... I tried loading sprinter and low
> and behold the temperature works fine! It shows
> the correct room temperate and then when I press
> heat to 185C in pronterface it heats and stays at
> the set temperature!!

1. Which motherboard did you set in Sprinter? 35 doesn't exist in Sprinter
2. Compare the settings in pins.h Marlin - Sprinter, may be the Temp-Sensor is not connect with the same pin.

Marlin > pins.h:

  #define TEMP_0_PIN         13   // ANALOG NUMBERING
  #define TEMP_1_PIN         15   // ANALOG NUMBERING
  #define TEMP_2_PIN         -1   // ANALOG NUMBERING

Edited 2 time(s). Last edit at 08/12/2013 03:52PM by flurin.

I seamed to have fixed the problem, I will hopefully accurately describe what worked if anyone else is having issues.

Try changing (uncommenting) the three preconfigured hot ends to find one that is close, then run an PID tune to get the values as close as possible. Link below

[www.soliwiki.com]

Thanks for your help Flurin