Power Loss Print Recovery

This post is about successful power loss print recovery after 15 minute outage. It includes information about hardware option of MKS PWC V3.0, it enables power loss monitoring, and power off when print complete. I purchased a PWC kit, for under $15, installed on Fokoos Odin-5 F3, and changed menu settings on MKS Robin Nano V1.2 control board via LCD. There is also a UPS board available that stores additional energy to raise Z axis, to keep nozzle out of print. With Marlin FW upgrade, both PWC and UPS are possible, but I have not tried that.

I am not associated MakerBase (MKS), but have a few printers with Robin Nano V1.2 control boards. Other manufacturers control boards, have similar power control options.

For power loss recovery to work, power fail must be detected, firmware must have capability to store layer index for restart, and sufficient residual power supply energy, to write layer index, to non volatile memory. When printer restarts, it loads failed job, with prefix start code, to preheat and home printer, do filament purge, then awaiting “start” by operator, to complete starting at failed point.

I have viewed a few printer reviews, and found reports of print recovery features, inoperative or buggy. Likely reason for this may be PWC needs to be installed, along with appropriate settings. Sales brochures, LCD menus and printed documentation for imported printers, often lack necessary information.

Shown below is a wiring diagram showing control board along with PWC, illuminated momentary control switch, power entry, and wiring. In my case power entry socket was same in my printer, so used it. Wiring was fairly short, but by placing momentary switch at back left side of enclosure, provided wiring worked without splices.

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In operation switch of power entry is turned on, momentary press of control switch bootstraps power control to printer control board. Printer can be set to “auto turn-off” in print job screen under “Options”, press “Manual” to toggle it to “Auto”. MakerBase has YouTube video on PWC installation here: MKS PWC tutorial with MKS Robin Nano - YouTube

My recovery experience was 100% successful, but it involved luck. Bed temperature dropped from 55C to 30C, quick preheat of bed kept print stuck to bed. I also preheated hotend prior to restart, since nozzle was stuck in print, that worked, also clipped small nub without disturbing print.

I have plans to purchase MKS UPS 24V and see if it will works to raise Z. I hope to post about that in future.

A little story about power recovery. 15 minutes? I broke this record by two weeks a couple of weeks ago. Including a complete tool head disassemble and reassemble.

I had a dual color print, where I had to change the filament. Do to a stupid user I pulled the filament out too slow. As a result the head pipe was clogged. I left the printer as I had no time for this and after about two weeks I disassembled the entire tool head (incl motor, fan shrout and fans) to reach the heat pipe. Cleaned it. Reassembled it and also did some wiring changes to make future disassembly a little easier.

Then I put the glass bed back into the printer and edited the gcode to start without printing the stuff already on the build plate. I also disabled bed heating, as the print still was rock solid on the bed. Five minutes later I had a finished two color print. :smiley:

This of course only worked, because I used glue stick on the glass bed. Without the print would be loose 5 minutes after I shut down the printer.

Back to the Topic: Power loss print recovery only works if your print sticks even when the print bed gets cold. If your prints get loose on cool down, PLPR won´t help anyone.

" Power loss print recovery only works if your print sticks even when the print bed gets cold. If your prints get loose on cool down, PLPR won´t help anyone."
That is good to know. I have had good results with Magoo, and I intend to continue using it. I have a glass bed on my Artist-D Pro, and love it. I have used glue stick and always had to reapply just about every new print, cleaning the glass bed often. With the Magoo I do not have to reapply often or clean the bed as often. I have had a couple of power failures and the Artist-D doesn’t want to recover properly every time, losing its memory location.