Led Air Duct Lights
Hey Everyone, I'm new to the forum and I know this topic has been beaten to death but I couldn't find any information specifically on what I was trying to do so here's to hoping I just didn't miss it.
I just got my printer and one of my first prints was the new upgraded air duct and bracket to give you visual access to the print nozzle, the one I printed has 3 holes for 3mm Led's and I would love to stick some light there so I have a better visual of my print area given its set up in a darker room. My question is where to pull power from for the Led's, My printer is a MK3s+, I can pick up some 3mm Led's from my local electronic shop for a few cents each but some forum posts I read said the power supply is maxed out during the heating procedure and therefore no extra load should be put on the system but I can't think 3 3mm Leds would draw more than a few watts if that, But then my second thought was to wire them to the print fan thinking that it really only comes on after the heat up procedure once printing had commenced and if I am not mistaken isn't that fan 5 volts already so it would save me the need to run a resister down from the 24 volt system the rest of the printer runs to my knowledge I get conflicting information if it runs 12 or 24 volt and I haven't had a chance to take my meter to it yet maybe someone on here has that answer as well. I'm in North America or Canada to be more specific if the difference is regional
RE: Led Air Duct Lights
The print fan is 5V yes. However its PWM controlled and has a sense wire on so its speed can be read.
If you wired leds in parallel then yes you could probably drive some small led's but their brightness would depend on the fan speed. You would also still need suitable value resistors for the leds. Each led should have its own individual resistor if they are run in parallel. You need to make sure nothing interferes with the sense wire otherwise you will get a print fan error.
It means the leds would be off for the first layer on a standard PLA filament profile and 3-4 layers for filament like petg (cant remember the exact layer the fan is turned on for those)
Is this new 'upgraded' air duct an official part ? I'm not familiar with it. I have my printer setup to allow easy changing of fan ducts and fans and have tested quite a few. Most didnt work as well as the standard one so I am always interested in trying new ones. Can you provide a link ?
RE: Led Air Duct Lights
This is the Duct system I am currently printing, Again new to this however it got good reviews.
https://www.printables.com/model/155387-remix-x2-delta-p-duct-v2r22-for-the-mk3s-new-flow-/comments
Yes I wasn't aware the fan was PWM so that is not ideal, Is there anywhere on the power supply I can pull power from and then resister it down without causing issues with the heat up procedure? Also do you know if it is 12v or 24v?
RE: Led Air Duct Lights
Mk3 fans are 5 volt.
mk3 power connectors are 24 volt,
it would be safer to source 24 volts direct from the power supply, and use a 'BUCK' regulator to lower the voltage, before using a dropper resistor to finally reduce current.
don't forget to include a fuse to protect your powersupply
preferably use the connections labelled A+ and A-, in the image above
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: Led Air Duct Lights
If they are not being used, perhaps the 5V and GND pins from the Raspberry Pi Zero header on the Einsy could be used (along with a resister). I don't know offhand if they have power all the time, or only if you enable the RPi port.
RE: Led Air Duct Lights
If you were going to use a fan as your power source, you'd want to use the hotend fan as it turns on whenever the extruder is warm and is not, to my knowledge, PWM controlled. It's either on or off. The cooling fan is PWM controlled, as others have noted.
The MOSFET that switches the fan is rated at about 1.5W and 2A. The latter will be the limiting factor given the rest of the specs. The fan is going to have a current draw of about 150mA. There is a red LED on the board that will draw 1-2mA. A few super bright white LEDs, each pulling 15-20mA, is not going to overload the MOSFET. Five LEDs @ 20mA each is less than the fan load an would only up the total to around 250mA.
RE: Led Air Duct Lights
The author of this remix of the delta-p with LEDs includes links to the 24v LEDs he used, as well as the wiring connectors. Worth a look.
https://www.printables.com/model/133276-remix-delta-p-for-mk3s-with-led
Cheers
RE: Led Air Duct Lights
I believe the hot end fan IS PWM controlled, there is a secret experimental menu, discussed in Prusa Knowledgebase which allows you to modify the cold end fan, to permit non Prusa fans to provide adequate cooling.
https://help.prusa3d.com/article/experimental-menu-mk3-s-_161213
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: Led Air Duct Lights
He does and it is much appreciated however being in Canada by the time I get them shipped here and exchange its almost $50 where I can go to my local electronics shop and get 3mm 5v leds for .35c a piece and worst case a 24v to 5v resister for .75c.
RE: Led Air Duct Lights
Okay, well there’s that then…
I think Patrick’s suggestion re pirating power from the hot end fan is a good one.
Good luck, let us know how you make out.
Cheers
RE: Led Air Duct Lights
Ive considered adding some LED lights, but I dont think I would take power from the printer. I'd mor elikely use a USB power back and run the LEDs completely separate! lol
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RE: Led Air Duct Lights
He’s talking about adding LEDs to a delta-p fan duct, so they will be moving with the extruder.
Tapping power from the hotend fan would save running additional wires back to the Einsy box. The nominal current draw shouldn’t be an issue.
But nothing wrong with adding a separate power supply and doing it your way!
Cheers