OK, not 30% upon closer inspection. More like 15%, maybe 20. That's more believable. A deeper buffer will smooth things out some, but can't compensate for 'long term throughput is still too low'.
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Replying to @xiphmont
Have you discovered monster nozzles yet? (As in, 1mm or greater.) Does a lot for throughput.
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Replying to @NYarvin
Unless paired with an equally monster heatblock, heater and melt zone, a bigger orifice can't move more plastic than the thermodynamics can melt... An e3d v6 is going to be limited to 8mm^3/s nominal with PETG (12 if you're pushing it) regardless of nozzle size.
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Replying to @xiphmont
Huh? My E3D v6 clone with a 40W heater and a 1mm nozzle puts down a 1mm wide * 0.7mm high strip of PETG at 30 mm/s just fine. That's 21 mm^3/s.
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Replying to @NYarvin
How long can it do that, and which PETG? :-) I see cold adhesion failures and texture changes up over 12mm^3/s with PETG that has a high pigment load. I don't exceed that printing masks here. 14mm^3/s produced brittle prints. e3d's official v6 rating for PETG is 8mm^3/s.
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Replying to @xiphmont
It keeps it up indefinitely, even running prints which involve nearly constant extrusion. This is Overture brand white PETG (my first whack at PETG, bought as a cheap experiment.)
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I'll do a speed-of-light calculation here. This data sheet: https://devel.lulzbot.com/filament/Rigid_Ink/PETG%20DATA%20SHEET.pdf … seems to have all the relevant numbers, including heat capacities at various temperatures up to and including melting.
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Using an eyeballed rough average of those heat capacity numbers, and plugging it into 'units', I get: You have: 1800 (J/kg/K) * 240 K * (1.27 g/cm^3) You want: watt / (mm^3/s) * 0.54864 So a bit over half a watt per mm^3/s.
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Which means a 40 watt heater tops out at maybe 70 mm^3/s. Of course that's absolute maximum speed, ignoring practicalities like heat loss to the outside. And thermal conductivity might be the real limit here, making this calculation irrelevant. But raw wattage isn't a problem.
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Replying to @NYarvin
Hm, well, my 30W heater can't even hold 265C at idle if the cooling fan is over 35%. No sock, I keep shredding them. But I think the real limit is the surface area (interface cross section) between nozzle inner bore and plastic, then heat conduction through the plastic itself.
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As for conduction, I guess that's why those "volcano" brand nozzles are unusually long.
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Replying to @NYarvin
That's the claim, yeah. Haven't tested it religiously myself, but it makes perfect sense.
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