Extra power to hotend with big nozzles?  

Lars Clausen
Active Member

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? 


Posted : 09/05/2020 9:30 am
Illustrious Member

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.

This post was modified 9 months ago by bobstro
My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 09/05/2020 3:44 pm

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