Bed Temp Overshoot / Slow start

General Discussion
1

Hello

Klipper newbie… :woozy_face:

I followed the setup instructions and almost everything is great. Thanks for all the content
There is currently one issue I have. I did a bed pid tune twice and always finished with save config but the bed temp always overshoots like 5° and stays there. This also leads to issues starting a print, because the printer waits very long to reach the bed temperature because they are too hot or doesnt start at all.
Printer is a Genius with an AC bed and a SSR. I never had these issues with Marlin.

thanks
jan
klippy.log (447.5 KB)

2

Unfortunately, this can happen sometimes with high power bed heaters that are well insulated. There are a few different techniques that one can try:

  1. Change your start scripts to not use M190 and instead use something like TEMPERATURE_WAIT SENSOR=heater_bed MINIMUM=60.
  2. Manually tune the PID parameters (eg, PID controller - Wikipedia ).
  3. If running in a chamber, it may make sense to position the layer cooling fan over the bed and run it at full speed during bed warming. This heats the chamber faster and makes the bed cool faster (which can improve the PID response).

I’m sure other techniques are also possible.

-Kevin

3

Thanks
Will try :ok_hand:
I guess I need to work through the klipper command reference :slight_smile:

4

thanks, works well. using the wait command.
will try to tune the pids by hand… Well with my fpv copters I’m not really good at this, but at least I already understand the principles :wink: