Increase volumetric flow rate using a longer nozzle

Question

I'm looking to increase the printing speed, through increasing the volumetric flow rate, which is currently at 5 mm³/s. Larger amounts cause the feeding mechanism to skip steps.

I'm running at 190 °C, which helps with easier bridging less stringing and personally see no reason to increase the temperature to the popular 205 °C.

So, my thought process is the following: since I run at lesser temperature, there is still potential for the heating block to provide more heat and I need a longer nozzle to accumulate more heat and provide more surface area for transfer to the fillament (PLA), to speed up the melting of the plastic inside the nozzle (which seems to be the bottleneck).

That's similar to using larger tips for soldring iron, when faced with heating up large surfaces in order to desolder something large, since we need to stay at precise temperature, and need to increase the heat supply as well.

The suggested solution is to switch to the E3D's Volcano "everything included" kit. Which is nice and cool, but I don't think it's that necessary.

• Is it possible to just switch to a volcano nozzle? (Manufacturer#: VOLCANO-NOZZLE-175-0400)
• Would it actually noticeably help to increase the extrusion speed?

Current setup:

• Ender 3 Pro, no mods
• Classic 0.4 mm nozzle

Answer 1

This is opinion-based, but the volcano has drawbacks that affect print quality, mine is oozier and sloppier than a V6 with the shorter, more precise melt zone. It isn’t a slam dunk upgrade, more of a special applications part. I think there is no point to using a Volcano unless you’re running big nozzles fast, like .8 mm.

Your 5 mm³/s throughput is low, the V6 is generally known as a ~13 mm³/s volumetric throughput, vs the Volcano at 25 mm³/s. This is due to the low temperature you favor, possibly something not ideal with your extruder. I could see...

• just living with the slow speed. I realize I vastly prefer print quality over print speed because one takes no human interaction and the other does.

• do what everyone else does. go hotter, plastic viscosity goes way down even with a 5-10 degree increase

• increase extruder torque. If you can increase stepper current safely (know the limit for your driver and motor!) with a trim pot on the stepper driver, you may be able to get more torque before the motor skips steps. This can increase motor temperature. If you get more torque, at some point the filament will slip and get carved up by the extruder’s hobbed gear. Double geared extruder designs like Bondtech can grip the filament from both sides and get more traction on the filament if you want to get diabolical shoving the filament.

• use a larger nozzle for faster printing at your preferred temp. I’m loving the .6 mm nozzle for bigger prints. It has most of the detail of the .4 mm but double the plastic comes out. A larger nozzle hole means less pressure in the nozzle at a given temp and extruder feed rate

If you think the extruder might not be all it can be, try heating up the nozzle hotter than usual, and get the extruder going slow and steady, and pull a little on the filament by hand, see if it skips steps easily with a little resistance. It should pull pretty strong. I had a failing wire to my extruder that manifested in wimpy extrusion.

Answer 2

Yes, the Volcano or the Super Volcano allow for larger flow rate (typically when using larger nozzles), that is where they were designed for. Just the nozzle will not help you, you need this larger nozzle shaft to be inside a Volcano heater block, else you cannot transfer the heat.

According to measurements from Metaform, the volumetric flow of a Volcano hotend is larger than the regular E3D V6 hotend.