Remote Power
Hi..
new to prusa printers, but have been playing with my Mk3 for a few months now, and am getting ready tin install the MMU2 and rev 3 upgrades this week. general question about power needs. I would like to set up a way to remote power off the printer in case of bad print. often I am doing 30+ hour prints when I am away from home. I monitor them using a WYZE webcam, and have been able to use octoprint and PiW to stop printing previously, but I understand this will not really be an option for the MMU2 kit. I plan to take out the Piw board when I rebuild the printer for rev3 and MMU, but have been thinking how I would be able to turn off and stop print one the MMU is in place.
best option I have been able to come up with is to use a IP switch, which I could then log into to turn off. I have one industial model used for server backplanes laying around, and am sure it could handle the PSU of the mk3+MMU.. but then though that would look awful in my office on the desk where I keep the printer.
Next thought was to use one of the ihome or (preferably) idevices outlet switches and plug the printer into that. it would be better for control as I could just use the homekit app, as opposed to having to set up a new subdomain to access the IP switch, but I dont know if the switch itself would be able to handle the power needs of the printer+mmu.
Online, the specs are listed as:
Power Input: 120 VAC, 60Hz
Number of Power Outlets: 1
Resistive: 1800W
Tungsten: 600W
Motor: 1/2 HP
does not mention amps at all..
Has anybody had any experience with using one of these? I know i will just be able to turn off the printer, but if I see a misprint or a problem developing, that is all I would really need to do.
Any other suggestions?
Thanks
Steve H
Re: Remote Power
I've used in the past a TP-Link HS110 (rated for 3500w AFAIK) and a Sonoff POW (rated for 16Amps), both has Power consumption check, so you can know how much your printer is using :P.
Cheers
Re: Remote Power
Hi Steve
Online, the specs are listed as:
Power Input: 120 VAC, 60Hz
Number of Power Outlets: 1
Resistive: 1800W
Tungsten: 600W
Motor: 1/2 HP
Resistive value, is for simple loads... highest value but least likely.
Tungsten value, is for loads that come on with a 'BANG', when cold, tungsten filaments are relatively low resistance, so the inrush current is disproportionately high, in comparison to the running load... (Semiconductors are the fastest fuses on spindly legs... so the manufacturer is reducing the total load to manage the inrush current. )
Motor value, relates to an inductive load where back emf's are an issue... so the manufacturer is limiting the load to reduce potential damage due to back emf's
1 horsepower is approximately 750 watts, so 1/2HP is approximately 350 watts. (this is the lowest, reported, supported load)
To the best of my recollection, the Prusa power supply is rated at 240 watts (OUTPUT) (input requirements will be higher)
if the power supply was :
hugely inductive and
had a conversion factor worse than 70% efficiency and
Running at full load,
then you would be risking damage to the power switch.
However switch mode power supplies are not usually highly inductive. and usually have a better performance than 70%, your planned switching times, are before beginning a print (Switch on) when the power output will be minimum, and mid print, when your power output will be moderate.
so on the balance of probabilities, your remote switch will be adequate.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Remote Power
Many people are controlling their printers (turning on/off) with TP Link smart plugs or with Domoticz switches or with Belkin Wemo switches or with Tasmota switches or your own relay (and use PSU Control plugin). All of them are supported in OctoPrint with their corresponding plugin so you can turn it on/off remote or automatically turn off after X time once print is done.
You can complete the combo with OctoPod that is an open source OctoPrint client for iOS. You can control any of those plugins in your iPhone, iPad or iPod. We are now beta testing the Apple Watch app!
Re: Remote Power
I use a Sonoff switch (modified with ESPEasy), just a few bucks off ebay.
Re: Remote Power
If you just switch the power off with a hot extruder, does that not invite heat creep? I understand that sometimes a clogged extruder is preferred to a mangled print/plastic ball of death on the extruder. Is there another way to stop the print remotely without a full shutdown?
Re: Remote Power
That sounds like an "emergency" shutdown. The OctoPrint plugins that I mentioned support a "planned" shutdown. They can turn off the printer (if configured to do so) after print is done and temp has reached desired temp or after X number of minutes after print is done. You can also do an emergency shutdown if needed (from your phone, for instance using OctoPod) but as you said that is not ideal but better than letting the printer keep running. You could also do an "emergency" stop rather than a shutdown if that is what you need. Probably a better choice.
Re: Remote Power
Any other suggestions?
Hi Steve. I think you only need Octoprint. There is no need to power off the whole printer. Using Octoprint you can always stop the print remote. It will work with MK2/3 or with any MMU device as you are using the regular STOP PRINT function on the printer.
This is the way I'm doing right now while I'm at work. Just watch your preferred IP-cam and click STOP, if needed.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
Re: Remote Power
Hi Steve. I think you only need Octoprint. There is no need to power off the whole printer. Using Octoprint you can always stop the print remote. It will work with MK2/3 or with any MMU device as you are using the regular STOP PRINT function on the printer.
This is the way I'm doing right now while I'm at work. Just watch your preferred IP-cam and click STOP, if needed.
Well this is assuming that software and firmware are still working... I'm a bit wary of relying on them for safety. I feel better with a nice switch that cuts off the power!
Re: Remote Power
Well this is assuming that software and firmware are still working... I'm a bit wary of relying on them for safety. I feel better with a nice switch that cuts off the power!
In my two years 3D printing with my MK2 and MK3 I've never seen the printer firmware crashing. Even if it would crash, USB connect/disconnect through Octoprint forces a hard printer reset.
You're also relying on your internet connection to home (router), the network switch and the IP/power switch. I don't see a difference here.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram