Really Fast Heating of the Nozzle...?

I have been experimenting with a heater cartridge to heat up my nozzle and I have noticed that it heats up REALLY fast. It will overshoot my target temperature by 30+ degrees and then eventually settle back down and be constant. While it is awesome that the heater cartridge can generate that much heat that quickly, my thermistor doesn't seem to react quickly enough. Is there a setting in the firmware to adjust the amount of times per second that a reading is taken with the thermistor?

Hmmm...

Need to know which firmware specifically, but yes, there should be adjustments in the firmware/EPROM settings that allow you to tune the PID, assuming you have PID heater control turned on.

Here's how PID controls work.

As was said, check out PID control, depending on which firmware you are using.

I don't think the question was about PID tuning, it was about increasing the frequency of temperature measurements. Can that be done?

If it heats too fast for the thermistor to respond then reading it more often won't help much but tuning the PID will.

In Marlin's configuration.h it has this:

Quote

#define PID_dT ((16.0 * 8.0)/(F_CPU / 64.0 / 256.0)) //sampling period of the

so possibly it can be changed but that will also affect the weight of the Ki and Kd terms.

There is also a PID_MAX setting to limit the current, which would allow it to heat slower.

I would give the Marlin autotune a try before changing anything else.

---

[www.hydraraptor.blogspot.com]