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Extra power to hotend with big nozzles?  

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Lars Clausen
(@lars-clausen)
Active Member
Extra power to hotend with big nozzles?

So this is presumably something that smarter people than I have considered at length, but I would like to understand it a little better: 

When printing with a 0.8mm nozzle, the main speed limit seems to be the volumetric flow rate, rated at 15mm^2/s by the e3dv6. When I tested increasing extrusion speed, I got up to 19mm^3/s before the extruder started clicking. But much earlier than that, the filament curled up rather than flow straight, something I take to be a sign of colder extrusion. I took out a power meter and found that while during heating the printer used ~50W, while just keeping the hotend at temperature and extruding, it used ~30W (as opposed to ~10W when doing nothing). My conclusion is that the power input to the hotend is determined solely by the PID-derived settings. 

Would it be feasible/make sense to use the known values of amount of filament needed to be heated to increase the power to the hotend when a lot of filament is going through? 

Thanks,
-Lars

Posted : 09/05/2020 8:30 am
bobstro
(@bobstro)
Illustrious Member
RE: Extra power to hotend with big nozzles?

If the hotend is maintaining temperature, is varying the power going the ultimately change anything?

I've been getting spectacular throughput results with different filament types and nozzles. With a 3D Solex Matchless 0.6mm nozzle mounted and printing PETG, I can print plastic as fast as the extruder can feed it, though print quality suffers.

11.5mm^3/s is a safe value for PLA through a 0.4mm nozzle, but results are very different with other materials and nozzle sizes.

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Posted : 09/05/2020 2:44 pm
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