From time to time I experience power losses at home. Whilst the H2D printer asks me if the print should be resumed and usually recovers properly, I noticed that it takes a while to reheat the bed: it heats the nozzle first, then it does some sort of X-Y homing, and only then it starts to heat the bed again.
Since my main fear is the print coming off the plate due to it getting cold, I’d prefer:
the printer to reheat the bed automatically upon power on, even before asking me to resume. Make it an option for before the print starts, if other safety concerns are at play.
if the bed is not yet heating and the user selects to resume the print, heat the bed first.
What do you think about these suggestions? I find them useful to me, but I am curious what other Bambu printer owners believe.
Sounds like a good change. I suppose you can work around it by manually changing the bed temp as soon as the printer turns on again and it should begin heating immediately.
I agree. That’s why reheating the build plate first is important, at least as an option. It doesn’t have to restore printing - just heat the bed.
Imagine you had a two-second power loss after four days of printing, during the night.
Scenario A: the printer reboots, detects the power loss, displays the option to continue on screen but does nothing (current situation)
Scenario B: the printer reboots, detects the power loss, reheats the bed and waits for confirmation to resume.
Which scenario would you prefer? I believe A will definitely cause the print to fail.
Yes, scenario B may cause me to waste energy to keep the plate hot for a few hours until I wake up, but it will likely save the print.
I actually wrote this post immediately after a 10-15 minutes power loss. Every moment counts and the build plate temperature dropped by 10 degrees. Had I not been near the printer to resume immediately, print failure were guaranteed. Fortunately, in my case, I was able to resume successfully.
What if the power fails on the first layer and, after power is restored, the bed reheats while the nozzle is still pressed against it—could that cause heat-creep in the hot end?
There’s no perfect solution, I agree.
However, since the point was identifying better ways of handling a power loss, what do you think about the following sequence?
Lower bed by a few millimeters if possible
Do the nozzle short home magic it does already
3a. If using AMS, attempt to remove connected AMS filament if possible, or clear tube if AMS reports it’s out of filament and it’s still in the extruder.
Leave printing head to above the chute with cold nozzle
Chances are a failed print won’t happen with a maxed out print volume - so lowering the bed will work. Removing the filament plus cold nozzle should limit clogging.
Lowering the bed without first reheating the nozzle will almost certainly cause the print to fail. The actual outcome depends on the print’s state at the moment of the power loss. In practice, the only viable approach is to let the printer resume unattended—even at the risk that the job has already failed—so that onboard monitoring can detect a failure and automatically stop the print as usual.
Interesting suggestion. I haven’t thought of that. Thank you for sharing.
It might actually work for H2/X1 printers, but the others have no monitoring.
