High temperature (400 degrees) hotend cooling
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I want to try new materials like PEEK but they require hight temperature up to 400 degrees....
Does someone has experience how to cool the hotend in such conditions? -
@c310 Hi!
If you want to print PEEK you also need a heated chamber and therefore I would say only a water cooling system is good enough.
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When I printed PEEK at 400+degrees, the only thing I changed on my stock E3D v6 setup was to swap the thermistor for a thermocouple. These days, I'd also use a copper heat block & nozzle. Other than that, I just use the same cooling as I did for everything else.
Your bigger problem will be getting enough heat into the process - a super hot bed and ideally a heated chamber. At the very least you'll need to put it all in a box to stop draughts.
Don't try printing PEEK just for fun though. It's expensive material and it by far the hardest material to print and get right that I've ever come across... particularly CF PEEK. There was nothing fun about it.
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Did. Have every problem you can think of. The only thing I did not have issue was hotend
(my own design, not something you can mass produce, handmade 100%, my own lathe, mill, many destroyed, no changeable nozzle, hand wound heater..). That printer was scrapped some years ago but in order to solve problems- no belts, I used 1605 ballscrews
- water cooled steppers. even with steppers outside of heated chamber they were getting hot trough the ballscrews. It would be smarter if I did not direct drive screws but linked them to motors via short closed belt but I had issues finding locally small closed loop belts so I didn't go that way. It was enough to air-cool steppers but since I was already using water for other stuff I water cooled steppers too
- water cooled hotend + water cooled extruder made 100% out of aluminium (and steel hobbed bolt)
- heated chamber (70-120C depending on the material)
the major issue unsolved was bed adhesion. Getting stuff like HDPE, PP, PEEK, PEKK to stick reliably ... the failures became too expensive so I gave up.
If you are not using chamber you have zero issues with cooling the hotend, those high temp materials have high Tg so your "throat"/"heat break" can be lot hotter than you are used to, also at higher temp differential between heat sink and surrounding air you remove heat much easier and faster so again dropping temp down is simple. Problem is that without heated chamber parts will warp (even small 20mm cube will have warped edges) so you want heated chamber, and inside heated chamber the temp differential is not big enough and cooling becomes a huge issue so - water cooling.
Also, bridging, overhangs, this don't work. To solve that I used part cooling with "outside air" trough rubber hose. That "worked" to a point.
Second reason you want chamber is toxins, at those temperatures different kind of toxins are released from plastics so you really want to vent that out of the room you are in.
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One addition, today you can get "Nano Polymer Adhesive" from visionminer. That stuff is worth every penny. If that stuff existed back in the day I'd probably be still printing high temp materials, but without something like that using different glues to make first layer work became too expensive to continue. So if you are trying out any of the high temp stuff, don't wander around, get nano polymer adhesive!!!
