Hello! How much cooling DOES the Hemera actually need? I am wondering if people have tested/tried various fans in combination with it, as I have done my own "replacement" test. Lets be real, the stock fan is loud af. I have looked up the fan used by the Hemera and got some... very weird results. According to the label of the fan, it is the following one: https://szdcfan.en.made-in-china.co...ars-Warranty-Ball-Bearing-DC-Cooling-Fan.html, specifically the XYJ12B4010M, which has specs more or less equivalent to this fan: https://www.tme.eu/hr/en/details/mf40101v2-a99-a/dc12v-fans/sunon/mf40101v2-1000u-a99/. I have bought this Sunon fan to test it. Having them blow side by side, it feels like the Hemera's fan blows much more air. This leads me to believe that the Hemera fans are mislabeled, as it is often the case with Chinese products. I have mounted this new Sunon fan on my printer, just to test things around and see if I can get away with a quieter fan, and honestly, its been fine so far. I have used a thermal probe to measure the temperature on the lower right hex screw below the fan, and the max temperature it reached at any point in time during a 220 °C 1h30m print was 33-34 °C. I don't know if there might be some future implications from this replacement however, and what is the temperature on the internal part of the heatsink. That said, I have a few questions: Has anyone tried to replace the stock fan with another one like how I did? For instance with a Noctua fan which obviously has a much lower flow rate. What is the expected temperature of the heatsink on its side during prints? Should it be warm at all or completely cool to the touch? Does the motor's heat leak into it as well (this might be the source of my measured 34°C on the hex screw)? What are the real specs of the original fan used on the Hemera? I think I will need a bit of help from E3D's engineers here as well, haha EDIT: I have ordered a way better fan now which has a similar noise level like the one I've recently replaced the stock with, but it is 2x thicker (also got the screws to go along with it): https://www.tme.eu/hr/en/details/mf40201v2-a99-a/dc12v-fans/sunon/mf40201v2-1000u-a99/
My hemera has the older Titan style clear 40mm fan (also noisy AF) as my toolchanger already had the wiring with a plug in place so wanted that style of E3D fan for quick installation and ease of dissasembly. I recetly ran a 19h print in my enclosure tha was 57-60 degrees air temperature measured about 2cm above the heatsink at all times, polymaker PC-Max PC material with no issues whatsoever. I also often print ABS in similar conditions. Perhaps peoples issues are more around printing PLA on all metal setup, though I though we got past that about 5 years ago... The heatsink fan was on 100% the whole time. I used nuctua heatsink compound on the threads of the heatbreak because it was to hand. I also tapped the heatsink with M3 machine screws instead of the nasty self tapping screws E3D provide. I use a copper heat block, PT100 and Nozzle X nozzles for what that's worth. My issue with the Hemera is more about having to very carfully extrude 20mm at 5mm/s the retract 100mm at 5mm/s to remove filament so that I get a long whisp that can escape the gears. I had ALL sorts of hassle loading and unloading filament before I sussed that; including having to dismantle the thing due to plastic detritus jamming the gears up. None since.
I also tapped M3 threads (6mm deep) in the fan mounting holes of the Hemera heatsink. Then I used M3x16 bolts to mount my 40x40x10 Sunon MagLev KDE2404PFV2 fan (24V). That fan is quiet enough even at 100% and seems to give off a more than adequate airflow (11.9m³/h at 5900rpm)
Is there a spec somewhere about how hot the heat sink and motor are allowed to get? i broke my orig fan, and 1 replacement already (don't go near with screwdriver when running I ordered some various replacements, tried to get what i thought would be enough static pressure, including a 40x40x20 to try. but it would be nice to know i am not causing damage.
Can someone suggest a good 12v fan? I only print PLA and petg, so my temperatures are max 220 or so... I see loads of Sunon 40x40mm fans, but have no idea which would work...
I have now mounted this Sunon fan and I can definitely tell it blows way more air than the previous one I've used: https://www.tme.eu/hr/en/details/mf40201v2-a99-a/dc12v-fans/sunon/mf40201v2-1000u-a99/ The fan is also quite quiet, but you need longer screws (I've used these, as they are compatible with the original ones: https://www.tme.eu/hr/en/details/b2.9x25_bn14064/screws/bossard/2097672/). So far, its been working well, and I definitely have the peace of mind that I don't have an underpowered fan. If the original fan that I have linked in OP is correct, then this is how this Sunon fan compares: Original Hemera fan: 11.92 m3/h air flow, 4.51 mm H2O static pressure Sunon fan I just linked: 13.01 m3/h air flow, 4.32 mm H2O static pressure While the new fan has a tiny bit lower static pressure, it greately makes it up with the air flow. I think it is safe to say that it is adequate.
Are you able to test what temperature your motor and feed part are running at? My motor seems to be running at 40-50c with a 80c bed temp and 240c hot end. i am looking for e3d to give a safe operating temperature range for the stepper motor.
That sounds quite okay for the motor I would say. Be sure to properly tune the current for the motor as it is probably different from the motor you had before. Refer to this: https://e3d-online.dozuki.com/Guide/05+-+E3D+Hemera+Current+Adjustments/143?lang=en
I'm having trouble finding one of those Sunon fans you recommend that ships to the UK and doesn't charge just as much for shipping as for the fan itself!
I have been using a Noctua 40x10mm fan for my Hemera on an open air railcore printer and it is more than adequate. The heatsink is barely warm to the touch during printing.
I have read the devs indicate that the noctua does not provide enough cooling, He did mention you can get away with a Noctua if you use the Titanium heatbreak when its available.
https://e3d-online.dozuki.com/Answers/View/483/Replace+stock+Cooling+Fan+with+Noctua+4010 Here's an E3d employee saying it should be fine...
I'm absolutely not claiming to be a fan expert, but I intuitively suspect that "free airflow" may not be the only important property to look at, and that "static pressure" is also important given the fact that the air must be pushed through the Hemera's heatsink channels?
https://www.reddit.com/r/3Dprinting..._their_new_extruder_hemera/f9k4cms/?context=3 Here is one saying it doesn't cool enough. doesn't matter, we all do whatever anyways.
I am sure for some situations the Noctua would be inadequate. I rarely print PLA or any layer under 0.25mm, and I only print larger structural items that don't have a ton of retracts per layer (parts for robots mainly). That would make my normal usage very tolerant of small amounts of heat creep and I am sure the high material flow rate of thick layers helps as well. I just couldn't stand the obnoxious sound of the stock fan. It was by far the loudest thing on my printer.
Don't have a dB meter so I cant say for certain, but I reversed the flow direction and it seems quieter, probably because it's not blowing toward you.
I think you're on to something. As an experiment, did the same with our vacuum cleaner, and it sounded much better!
Was this the result of random testing and/or reasoning? I can't find anything relating to this on the e3d Dozuki for the Hemera. My first attempt to unload filament has jammed the extruder and, I suspect, ground the filament, but even at temp I cannot extract the filament, it just won't pull back. I've mulled it over overnight and had arrived at the impression that I'd retracted too fast, bringing a mess into the heat break which had this jammed. Your solution seems to indicate a desire to avoid exactly that situation, slowly ejecting to allow cooling to happen slowly. I'm not too worried about this, but would have been nice to read it somewhere official. When you do have a jam like that, what was your solution?. I'm thinking I'll need to permit some heat into the heat break in order to be able to perform a cold pull at about 90 to 100.
