4 KW Heat Bed Tuning

sozkan

I am glad that you got a result. The reported gain of 34.9 implies that the maximum reachable temperature will only be about 35C above ambient. Will that be enough for you?

How large is the bed?

Bed is 120 cm in diameter, 5 cm thick aluminum custom self-made in 4-kilowatt consumption.
We can cook something or use as Lab heater. It is very functioning
Thank you for your kindly help.
It seems it is working. Don`t get me wrong, but I will request a donation to your work for development from our University management. It was worth.

sozkan

@sozkan

Work in progress picture of Heat Bed

Phaedrux

@sozkan So you were able to successfully tune with M397 H0 D160?

dc42

Aha, it's Delta then!

sozkan

@Phaedrux said in 4 KW Heat Bed Tuning:

@sozkan So you were able to successfully tune with M397 H0 D160?

Yes, it was. Today It`s warned again about the slow heating issues. I have run the PID process again this time with D60 ( because it says D160 bad command )
It is solved again.
Thank you for concerning

sozkan

@dc42 said in 4 KW Heat Bed Tuning:

Aha, it's Delta then!

Yes, it is.

nhfoley

@sozkan

I greatly appreciate this thread as I'm trying to autotune a similar bed (very large aluminum plate with a 1.5KW heater).

It seems like I get a "Bad Model Parameters" in the M307 command whenever the D value goes above 70.

Since I have an (intentionally) somewhat underpowered heater, my dead time is probably right around there or a bit higher. This means I am not able to use the autotune on my heated bed, as it's still expecting more temperature rise than the heater produces. My approach now is to guestimate the model manually and then hopefully tweak it by hand once I can see how it's holding a temperature.

In general, it seems worthwhile to add a parameter to the autotune function which scales its expectations based on a user-input "guess" of how long the whole heatup process should take. I think this would correct a lot of the frustrations around autotuning I've had or seen others experience before.

Phaedrux

@nhfoley You may be interested to see this then: https://forum.duet3d.com/topic/19761/new-heater-tuning-algorithm?_=1605553260486

nhfoley

Actually, going to refine that prior post: It seems like, if I send a fully-formed M307 command, like:

M307 H1 A100 C800 D100 S1 V24.5 B0

I can program a higher dead time.

nhfoley

@Phaedrux Yes, thank you. Will follow along there eagerly.

sozkan

@Phaedrux You guys are the best Thank you for the progress.