Prusa-firmware-buddy: [ENHANCEMENT] Isn't heat bed heating unnecessary when loading/unloading filament?

[fuelflo]

Printer type - [MINI]
Optional upgrades - [Filament Runout Sensor]

Is your suggested improvement related to an existing problem? Please describe.
no

Describe the expected functionality
When loading or unloading filament while NOT printing, the printer heats up nozzle and the heat bed. Often heating up the heat bed is even slower and you'll have to wait for it to reach 60°C.

Now I'm no expert, but isn't heating the heat bed on a lone filament change/load/unload unnecessary? First of all it would save a lot of energy if only the nozzle would be heated and also it would save a bit of time because the printer wouldn't need to wait for the bed heating.

[jokohoko]

I don't think the printer waits for the bed temp to start the filament change process.
And in a lot of cases the next step after changing materials will be actually starting a print.

So i would agree with the current logic that also heating the bed is the most useful method. A menu option to "also heat up bed" or "cooldown bed" in the change material process could be useful in some situations.

[fuelflo]

Hey,

I checked again and the MINI might not be waiting till the bed heating is finished, when only loading/unloading filament.

But when only unloading (like when you don't plan to use the printer for a specific time) it still heats the bed, which IMHO is a waste of energy and life time of the heater. When unloading, to load another filament after that, the heating still can be done in the filament loading process.

However, even when loading filament to print right after, the printer heats the nozzle to >=215°C (depending on the material) and the bed to >=60°C. After loading and purging the printer needs to wait and cool down the nozzle temp to 170°C (to prevent oozing of filament during mesh bed leveling I guess). So we could use the cool down time of the nozzle to heat the heat bed for people who want to print right after. And for people who don't want to print the bed would never have been heated unnecessarily.

[jbnjohnathan]

I agree that when you select "unload filament" the reason is often because you are not using the printer for a while. And as said before, if you do want to print no time is lost if the bed would be heated when loading the filament.