Need help connecting 12v e3d coolant pump to 24v system Duet 3
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I'm Using Duet 3 with 24v vin. The liquid coolant pump from e3d has no documentation besides that it's 12v and brushless. Current draw is not specified.
What pins I can use to connect the pump to Duet 3 board so it can still be temperature controlled?
My setup is: Duet 3, Tool Distribution Board, 1 Tool board and RPi.
400W 24v power supply.I searched everywhere and could not find straight answer.
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It says right on E3D's website that you need a dc to dc converter to use it on a 24v system. The other option I can think of is get a separate 12volt power supply to power the pump and wire it up using a DC to DC solid state relay. Control the SSR using a fan output from the Duet board similar to how you control an AC heated bed but just using a fan output instead. This way you can still set up the fan output to be thermostatically controlled so the pump operates at whatever temperature you set.
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@JamesM said in Need help connecting 12v e3d coolant pump to 24v system Duet 3:
The other option I can think of is get a separate 12volt power supply to power the pump and wire it up using a DC to DC solid state relay.
you can wire a separate supply through a duet output the same way as a dc/dc converter. (just make sure Vin or Voutl is higher than the voltage you use externally, and they have a common ground)
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@evomotors I'm in the process of converting to a water cooled hot end and I intend to run the pump from a separate always on (via a switch) 12V supply. The reason being that should a print fail and you hit emergency stop or kill power to the printer, you could end up with a hot end that is hot with no cooling, which could cause a blockage in the heat break. If you run thermostatic mode and are using the RPi, it could take 30 seconds or for the pump to restart after you restore power to the printer. I'm told that these pumps are very quiet so I don't see a need to have them running in thermostatic mode.
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@deckingman said in Need help connecting 12v e3d coolant pump to 24v system Duet 3:
@evomotors I'm in the process of converting to a water cooled hot end and I intend to run the pump from a separate always on (via a switch) 12V supply. The reason being that should a print fail and you hit emergency stop or kill power to the printer, you could end up with a hot end that is hot with no cooling, which could cause a blockage in the heat break. If you run thermostatic mode and are using the RPi, it could take 30 seconds or for the pump to restart after you restore power to the printer. I'm told that these pumps are very quiet so I don't see a need to have them running in thermostatic mode.
It is valid, but what is the point to run the pump for hours after print is done?
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@evomotors said in Need help connecting 12v e3d coolant pump to 24v system Duet 3:
It is valid, but what is the point to run the pump for hours after print is done?
It's no different to leaving the printer turned on for hours after a print is done - I tend to turn mine off personally.
Those pumps typically use about 0.4 Amps which is less than 5 watts so running cost is negligible. I used to keep tropical fish so am quite accustomed to running small pumps 24/7 but of course, it's entirely up to you what you do.
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@evomotors hey, if you figure out how to get it to work that would really be helpful. My setup is pretty much identical to yours and I’m still trying to figure out exactly what pins to connect it to. I’m a visual learner so a diagram would be best and I’m sure would help others.
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@1997alex said in Need help connecting 12v e3d coolant pump to 24v system Duet 3:
@evomotors hey, if you figure out how to get it to work that would really be helpful. My setup is pretty much identical to yours and I’m still trying to figure out exactly what pins to connect it to. I’m a visual learner so a diagram would be best and I’m sure would help others.
I used DC-DC SSR
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You need a converter, sometimes called a buck converter. I have a small bag of them, they convert DC voltages, like 24v in to 12v out.
Heres one with a display:
https://www.amazon.com/LM2596s-Converter-Step-down-Regulator-Stabilizer/dp/B07CVBG8CT/ref=sr_1_3?crid=2USO7411UY29P&dchild=1&keywords=buck+converter+24v+to+12v&qid=1598055994&sprefix=buck+con%2Caps%2C160&sr=8-3Like @evomotors said, you can use an SSR to switch it on and off. Is that overkill for this though? Wouldn't a regular relay be easier/cheaper than an SSR?
