Hi, I'm designing heated chamber printer and I'm looking for good extruder options. Hemera looks cool, but how it'd behave in 100C environment? Are there any plans for Hemera Aqua version? Or should I just design my own WC adapter?
Check the datasheet at https://e3d-online.dozuki.com/Document/UBaWiCkBAAlCkZBG/Hemera-Datasheet-(Edition-1).pdf Currently there are no plans for a watercooled version.
Great! I have'nt seen that before. So to operate under abovementioned conditions I'd need to effectively cool extruder and motor. As Radiator seems to enclose all extruder parts and motor has large contact area with extruder it should be possible. Temperature inside should not reach 50C, but I can also think about isolation and/or modification of extruder to withstand higher temperatures. All plastic parts can be also 3D printed from 316L if POM would cause any problems. High temperature bearings can be sourced (or I could just replace grease inside).
I'm currently printing in a passive but insulated enclosure that reaches 50 deg C at the tool head. No problems with the air-cooling of the Hemera so far; but I had to lower the motor current a bit to prevent it getting scalding hot. I'm currently at 6 hours into a 9 hour print at that temperature.
This is a bummer! My next machine will be for high temp and stinky filaments and this was on my wish-list.
Sadly the heatsink does have a couple of screw holes so you can't just run water straight through it. Having said that, the passageways are quite large so you could always push some thin-walled copper tubing (Squashed into an oval) in between the fins with some thermal paste to make up any gaps. A small metal plate over the top where the fan would go will keep the tubing in place. Looking at the fins, I think three tubes could be added and I'd personally run them in parallel.
I have a printer using those atop of a V6 heaterblock: https://www.aquatuning.co.uk/water-...blocks/10762/alphacool-mcx-ram-copper-edition (The small tubes are small but they seem to be just right + flexible. The water cooling is very effective. In computer systems you want to get rid of 200 Watts, but here it is like 15W.) To upgrade a Hemera I would mill some flat onto the front and solder/thermal glue/screw such a tiny cooler at the place.
Pribanic, can you please share more details? How mutch mm did you take off? How is the bearing housed at the moment?
I Will try something like this. Take off part of the cooling fins and mount the small cooling block mentioned above.
I have also been working on a water cooled conversion over the past week or so. The approach I am using is to print a block out of resin that will encapsulate the heatsink and direct water as appropriate, but without exceeding the space envelope of the stock fan. The desire to ensure the screws attaching the extruder assembly to the motor are accessible for disassembly has resulted in a few walls that are thinner than I like, but I am hopeful that the idea is workable. The "fittings" you can see are 1/4" OD aluminum gas tubing that press into interference fit holes. After several iterations I have something that fits snugly on the Hemera and the next step is deciding on a sealant to apply before screwing everything together and pressure testing. I am thinking RTV silicone is probably the best option, but something like Seal-all with a lower viscosity might be superior. The messy CAD file is here if anybody wants to mess around with it: https://cad.onshape.com/documents/9...f29980652a3b0068e0/e/4fea98f19528751ad4febaee
you could probably keep the size down with thinner tubing. The heat carrying capacity of water is huge. it only takes a trickle. If you have to carry away 20 watts (I think this is higher than realistic), 1 cm^3/s of water will result in a (20 watts/(4.2 J/calorie)) or about 5C temperature rise. 1 cm^3/s of water is 0.06 litre/minute or just about 1 gallon/hour. You could use 1/8" tubing or smaller, easily. It would also reduce the strain on the system. To keep the flow resistance down, you could bring in slightly bigger tubing and step down, but I suspect 1/8" (or metric equivalent) all the way through would work fine.
I used the same coolers you show here on another printer. The great thing is that they really can put heat away and the water tubes are very small. The can be bent and did not fail on my other printer for years. The micro cooler once solved heatcreep issues at an oldstyle hotend printer with passive peek style hotends. (Now those have been replaced by E3D V6 of course) But dont trust the connection between tube and heaterblock. Fix the tubes with cable ties so that the actual connection does not see motion.
I ended up sealing the block onto my extra Hemera with RTV silicone and tested it for a few hours last night using an old Danger Den 12V PC watercooling pump for circulation and about 4 feet of 1/4" aluminum tubing as a passive radiator (didn't feel like using my old 360mm radiator). With the nozzle temp set to 260C for 3 hours there was no leakage and the heatsink was cool to the touch. It is definitely overkill on flow rate and you could easily get away with smaller tubing and a weaker pump. I am currently printing out some mounts to attach everything on my railcore and then will do some long printing tests to further verify functionality.
I made this from an old piece of Alu. now all i need is a pump & the rest ;-) Onshape link here: https://cad.onshape.com/documents/1...771700451121bffc7e/e/2dbae6604ddca76b8f4fb2b6
