extruder not getting up to temperature

Hey there,

I got a new hotend recently but am having difficulty getting it up to temperature, it is definately capable of the temperature i'm trying to get to but once it gets around ~10 degree's lower than the goal, it turns on pwm and never gets up to temp. I am looking for how to fix this... I thought there was a command you can run in gcode to automatically calibrate 'something' but I do not remember what this is.

The hotend is "http://www.ebay.com/itm/G3D-Buda-style-HotEnd-v1-2-for-RepRap-and-various-3D-printers-Mendel-Prusa-/170998389688?pt=LH_DefaultDomain_0&hash=item27d04c5bb8"

marlin is configured as "// 1 is 100k thermistor - best choice for EPCOS 100k (4.7k pullup)" with the following settings.

// 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

Any assistance would be greatly appreciated.. Need to start printing again!

Sounds like the Temperature PID needs tuning.

In your Marlin Configuration.h,

What are these values set to?

#define DEFAULT_Kp
#define DEFAULT_Ki
#define DEFAULT_Kd


(I'm guessing the proportional part isn't high enough)

Edited 1 time(s). Last edit at 05/01/2013 02:36PM by ShadowRam.

Send M303 S200 to the machine and it will calibrate the PID values, which you can use to edit the configuration.h variables mentioned above.

I have NEVER had anything good come from M303.

In fact, it usually made performance worse.