3D Printer Water Cooling advice?
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I have a couple 3D printers that are enclosed (Raise3D N2/N2+) and I added heat to the enclosures over the summer. The X, Y, Extruder motors, and hot-end cooling are all in the heat.
I want to add water cooling for the steppers and hot-ends to eliminate filament jams when I'm running the box hotter and enable higher enclosure temps.
I don't want to have the cooling pump and fans running full tilt all the time, especially when the machine is idle.
I'm thinking of having one pump to feed all cooling circuits. 6 separate loops that all feed into a reservoir separately with a flow control on each line so I can ensure flow in all circuits and monitor (visually) for flow issues on any one circuit.
I figure I can run the pump on the output that is currently running hot-end cooling fans. It kicks on when the hot ends exceed 40C.
Would there be any benefit to PWM control on the radiator cooling fans to maintain a constant water temperature, or is cooler always better? IOW, just run the radiator fans full whenever the machine is hot.
My printers are in the garage and ambient temp can vary between ~10C & ~30C. Does the temp on the cold side of the heat break have any impact on print quality? Would there be any benefit to a consistent water temp, or would that be wasted time/effort/money?
Any advice from those of you who have water cooled would be appreciated.
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I run my pump when the hot end or chamber temp is over 40C. I have a diode at the end of each trigger. One going from the hot end thermostatic output and one going to the chamber thermostatic output, to the relay for the pump. My fans also exhaust heat from my electronics bay, so they run when the system is powered up, with a powered intake to the electronics bay. You could probably set this up without diodes with conditional operators if you are running a compatible firmware version.
I have flow controls on the returns of all of my tools and steppers, and I adjusted the flow by watching the flow rate out of the returns and making sure that they all were flowing around the same rate.
I don't know if cold side temp will affect much in print quality, but I assume that colder is better considering the limitations of watercooling with ambient temps.
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A few things.
If you have sized things correctly (and even a single 120mm radiator is plenty for a 3D printer in my experience) the temp of the water is surprisingly uniform along the loop; so having 6 separate loops, managing a manifold and in-line valves and staying on top of flow rates is probably total overkill.
Totally worth having the pump controlled by the duet. Will extend the pump life if nothing else.
Controlling the fans is probably an ambient noise thing more than anything.The critical thing with hot-end temp is keeping the cold side below the glass transition temp of the polymer, how far below isn't important (unless you are doing really weird things). This means that for high temp materials, you don't even need to water cool the extruder (seriously, PEEK and ULTEM can be printed on a good air cooled extruder, but your fan might melt) unless you have a really serious heated enclosure.
All that said, cooler is better in that it will extend the life of the motors... but not critical enough that I would bother with anything other than radiators, no need for TEC's or anything like that.
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@theruttmeister
I agree with you, the watercooling is overkill. You can have a single line with a 120 fan easily.
I put a watercooling with a 40x40 fan on a aluminium heatexchanger for the hotend and the extruder. The temperature stays at 25 deg max. -
Thanks for the input, folks. Sounds easy enough to execute. I'm using a stand-alone temperature controller for the enclosure, but running based only on the hot-end temp should get the job done.
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Just ordered a bunch of hardware to start working on this. I'm going with 240mm radiators just because my printers are big enough - I'll have the space. Going to run 6 circuits up to the motors and hot ends and back just so I don't need to mess with fittings and splits inside the machine. Might be overkill, but is also minimizing the failure points. The lengths of the tube runs won't be a concern either, as that would impact flow rates through different circuits. Figure I'll just run a blend of automotive antifreeze and water for the coolant. I know I'm not dealing with any temperature extremes - but even distilled water would likely have stuff growing in it before too long. Suggestions on a different additive for the coolant would be welcome. How it looks under black-light is not a factor.
If I run into any revelations, I'll let you know. Thanks again for your insight.
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@zemlin
I use simple automotive antifreeze too. The materials in the circuit are aluminum, stainless steel and plastic. The ratio of additive to destilled water is about 1/10.
I have no problems with oxidation or organic growth for the last 6 months./Julien
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Curious if those running liquid cooling notice any coolant level drop?
I'm running about a 120mm radiator and the pump tank is only about the size of a small drinking glass.
I've noticed a drop in level but no indication of any leaks anywhere.
Using radiator coolant.I only cool the hotend and have been very happy with the results.
As an upside, on the titan aqua clone I have the pancake stepper runs with no apparent heat rise even at full amps rating current.The rest of the motors don't get hot enough to worry about as it's not a heated enclosure, but it certainly couldn't hurt to cool them as the coolant temp I'm getting (only a few degrees over ambient) certainly indicates the system would handle it.
