Power Loss Resume  

RE:

No, it does not work. It CAN be done, but needs plenty of changes in the FW to be able to work. Do not expect it! But yes, I want to make it work. I have made a proof of concept implementation and printed a benchy with two plug pulls. I will have to write the feature from scratch for it to work in a user friendly way. As of now it was using the pause state as a yes no dialog 😀

RE: Power Loss Resume

Realistically unless the power loss is less than a few minutes it will end in tears. If the bed is allowed to cool either the part will detach or adhesion between the cold and the hot layers will be poor.

RE: Power Loss Resume

Hi, I agree with you on long power outages. I was only interested in the brief ones like few seconds or minutes. I'll stick to my UPS 🙂

RE: Power Loss Resume

Any update on this ? I am also interested in this feature

RE: Power Loss Resume

Nope, still no FW support. Sorry

RE: Power Loss Resume

Hello, I had the same question. But perhaps in a somewhat simpler form. I had an idea of using an APC UPS with a USB port. The principle would be as follows:

The printer and RPi are powered by the UPS; the USB from the UPS is connected to the RPi, which runs PrusaLink.

1) There is a power outage/ drop in battery charge below a certain percentage (this state will be detected using a script on the RPi --> it will read information about the UPS from the USB port; I don't know exactly how, but this shouldn't be a problem to figure out)

2) When the script detects a power outage/drop in battery charge, it would call a system command, something like "prusalink --pauseprintpowerlos"

3) PrusaLink would pause the print and save information (progress) about the current print and prepare for the upcoming power outage.

4) Power outage - nothing is powered on

5) Power is restored.

6) After the RPi and PrusaLink have been restarted, the print would resume (--> after user confirmation that it's safe to resume printing - the object is stuck to the bed)

Basically, it is only about the possibility of the existence of a "powerlos" command in PrusaLink that could be called from the CLI. Is this even possible, or is this also unrealistic? For me, it's one of the things to consider when thinking about upgrading to the MK3.5 - because of the possibility of having print resuming and PrusaConnect; that's why I came up with this solution 😅🙃.

Thank you very much.

RE: Power Loss Resume

Sorry, I forgot to write that I'm using RPi4 with USB connection to the priner (MK3S+ MMU2S) 🤭

RE:

Hi, once you have a UPS, the power loss recovery becomes a lot less useful. Once your print sheet cools down, the print will self release, that makes it work only for brown outs and short interruptions anyways.

A second problem I see comes from the missing fw support. If it does not execute the first part of the power panic routine, the motors of the Z axis could be inbetween steps. If I understand the routine correctly, we raise the gantry and put the motors at a full step, saving the info about where that was. If you don't do that, once the Z is powered down, it might move more than when at the full step point.

Then there is the problem of supporting different UPSes and setting it up and so on. If we're gonna put that much effort into it, we might as well do the regular power panic.

Those are my thoughts, what do you think?