I’m not sure how often you lose power and if it’s just a blip or hours at a time, but if you’re purchasing a UPS and leas acid batteries, it must be often, or, you have some pretty critical prints running. That said, my Bambu will resume reliably on filament changes, but I’ve had mixed success with even just pausing and resuming a print (this might be better now since the various firmware upgrades). I haven’t tried unplugging it during a print, but it would be a useless exercise because if the print and chamber and extruder cools down, I’m not sure if it would I would resume properly from where it left off.
So, I would look at this a little differently. If you absolutely need it to remain powered up, and you are buying batteries anyway, buy an inverter instead and use your household power to charge the batteries. If you consider cost, that would be much cheaper that a UPS for extended downtime (most low cost UPS’s just give you enough time to save work and shut down safely).
I had 3, 8hr+ prints fail due to power flickering for less than half a second over the course of 2 days… wanted to break something. I was looking into a UPS for just covering those stupid little blips or even 2-3min outages. If it was over an hour or more the UPS couldn’t handle it, but even then I wouldn’t be as outraged as I was for literally a light flicker shutting it all down.
For those saying use the firmware power interruption, anything longer than a few min and it’s useless. Your bed will cool off and the print will lose adhesion so restarting it isn’t just a press button and go command they advertise. Also be aware it has been widely known to cause print artifacts. It will pause the printer slightly to record to the cpu and onboard memory the toolhead position and what line in the g-code at about every layer. These frequent pauses allow filament to ooze causing blobs on the surface of the print. Pretty unsightly.
I’m not sure if that referred to my post, but I wanted to clarify that it only works on filament changes and is not for power interruption. During this pause and resume, my printer has sat for hours and resumed the print perfectly once I loaded the new filament, because the bed, chamber, nozzle, etc remained in a heated state.
Nah not directed at you at all. Moreso the companies that advertise it as a “failsafe” for unsuspecting users. Pause and resume is also built into most printers firmware, especially now and will keep the bed on. More advanced firmware like Klipper would require changing the config to make sure it doesn’t time out since it is adjustable.
The modern printers like the Bambu are pretty good at this stuff already, hands down the closest to an out of the box and hit printer that exists on the market today.
My 1000 watt UPS doesn’t have a noticeable delay (most don’t) and has saved me a few times up to an hour of power out on my Prusa Mini.
Funny in a terrifying way to watch the time remaining swing from hours to minutes when the bed heater kicks on/off and the steppers make rapid movements.
If you live in a an area that has sketchy power problems, you want an inverter with true sine, AC passthru, and automatic batt charging.
This is the inverter I am looking at: KISAE IC121040 Abso SW 1000 Watt 12V Inverter with 40A Charger. It should run my Mini, MK3.5 and my PC in my office at the same time. I put a power meter on my MK3s and it averaged about 100 watts by my guesstimation.
Add 12 volt AGMs and it could all be kept under your bench safely.
In my area the power outages are more frequent! Sometimes it’s 1 hr or even for only 5 minutes! And I have 13-14 hrs prints every day. So I am gonna test some sine wave inverters for the power backup to ensure there is no delay.
They should have a switching time spec. Look for <100 mSec switch time. The capacitors in your printer power supply will most likely prevent power dropping out in a tenth of a second or less that would cause a controller reset.
I’ll add to this, if you’re running Klipper on a Rasberry Pi like I am, it doesn’t have that luxury and any type of electrical loss will shut it down. So a UPS is a great insurance.
Hello everyone just tested and installed a sine wave inverter with 2 lead acid batteries and the printers run without any issues! It has a back up for 3 hours!
If those aren’t AGMs they might gas-off Hydrogen during charging. You will need ventilation. If you have never seen a battery blow up in someones face I can tell you it’s not pretty.
Yes they are not AGMs. But those batteries are placed in my store room with perfect ventilation! And unlike other rooms in my house that room is always chill !
Hey, I managed to build one for less than $600, I bought an ender 3 v2 and an ender extender bed plate, you can also get more add ons for it. The ender 3 v2 is basically the Honda civic of 3D printers, mod away.
