configure the bed heater

bernardomattiucci

hello,

I would like to make a change in the operation logic of the bed heater on my printer (duet2wifi) and would like to know if it is feasible and how, if at all, I should proceed.

Assuming that I almost exclusively print PLA with the bed heated to 50°C, I would like to have the temperature maintained within a range of a few degrees, say 5, the absolute average of which tends to decrease as the printing rate progresses.

I give an example.
I heat the bed to 50°C and start a print with 50 layers.
As layers are printed, the temperature of the print bed will continue to fluctuate between 45 and 50°C for the first 10 layers. Then it will move to fluctuate between 40 and 45°C for the next 10 layers, and then decrease again to 35-40°C for another 10 layers, then 30-35 for another 10, and finally 25-30°C for the last 10 layers.

Is this feasible?

Alternatively. is it possible to set the range from 40 to 50° only throughout the printing process? this way the heater would start much less often and I would save a tiny bit of money--since it is 1200 watts!

Thanks
Bernardo

Norder

@bernardomattiucci
You have to specify in your slicer from which layer height the print bed should have that temperature.

Google Translate
-- Original Text --

Das musst Du in Deinem Slicer angeben, ab welcher Layerhöhe das Druckbett die oder die Temperatur haben soll.

bernardomattiucci

@norder

Okay, this is not a problem.
I have already implemented in the slicer (ideamaker) a percentage control...

[if {print_progress}>25] M140 S45;
[if {print_progress}>50] M140 S40;
[if {print_progress}>75] M140 S0;

...which I will try in the next few days. But this is limited to changing the temperature of the plane. I would like that when the target temperature is reached, the heater is only operated when the floor temperature drops below a given value. Meaning.
if T => Ttarget then turn off the heater.
if T <= Ttarget-5°, then turn on the heater

So that you don't have the heater perpetually on.
The printer I have, self-built, has a fully enclosed chamber and the bed is thermally "insulated," so cooling is quite slow and I have no problem, thanks to the thermal mass, printing with the platen cooling.

Translated with www.DeepL.com/Translator (free version)

engikeneer

@bernardomattiucci but if you are using PWM or bang-bang control it is already only turning the bed 'on' for part of the time. That's why the temperature doesn't continue to rise!

Norder

@bernardomattiucci
The heating isn't on all the time. There is an LED on the Duet Board that indicates when the bed heater is heating up.

Another possibility to turn off the bed heating completely after the first layers is to choose the right filament and increase the print bed adhesion.

I always level my print bed very meticulously and clean it thoroughly before each print, I always print the first layer with 0.1mm (100% flow) instead of 0.2mm as most people do.
When the skirt is printed, I use pointed tweezers to test how well the print holds on the print bed (FR4 Blackprint from Printbay), I guess I then set the layer height to less than 0.1mm with the help of the baby steps.
I print mostly ABS-X from Minadax and Titan-X from FormFutura, and the prints hold very strongly (almost too strongly) on the print bed even after cooling to room temperature, so I turn the temperature down heavily after the first 5 layers (by hand) .
Only for large prints do I not go below 50°C... out of panic.

Google Translate
-- Original Text --

Die Heizung ist ja nicht ständig an. Auf dem Duet Board ist eine LED die anzeigt wann die Bett-Heizung in der Aufheizphase ist.

Eine weitere Möglichkeit die Bett-Heizung nach den ersten Layern komplett auszustellen ist die Wahl des richtigen Filaments und die Erhöhung der Druckbetthaftung.

Ich level mein Druckbett immer sehr penibel und reinige es gründlich vor jedem Druck, dazu drucke ich den ersten Layer immer mit 0,1mm (100% Flow) anstatt 0,2mm wie die meisten es machen.
Wenn der Skirt gedruckt wird teste ich mit einer spitzen Pinzette wie gut der Druck auf dem Druckbett (FR4 Blackprint von Printbay) hält, ich vermute ich stelle dann die Layerhöhe auf unter 0,1mm mit hilfe der Babystepps ein.
Ich drucke zum größten Teil ABS-X von Minadax und Titan-X von FormFutura, und die Drucke halten selbst nach dem abkühlen auf Zimmertemperatur sehr stark (fast zu stark) auf dem Druckbett, daher regle ich die Temperatur nach den ersten 5 Layern stark herunter (per Hand).
Nur bei großen Drucken gehe ich nicht unter 50°C... aus Panik.