I purchased a 0.8mm hotend for my X1C thinking that a 0.5mm^2 opening would print considerably faster than a 0.12mm^2 opening. I use mostly bambu filaments and I don’t mess with the profiles. Has bambulabs just not bothered to tune the filament profiles for this sized nozzle or is there some other reason that makes it totally pointless to give up the resolution you get with the 0.4mm nozzle?
When I played around with larger nozzles on my X1 a couple of years ago, I found flow not to be limited by nozzle size but by the heating chamber. At the time, I speculated that the chamber was identical across nozzle sizes.
Nowadays, a HF nozzle should be better. But I am not certain about max flow differences between HF variants of different sizes…
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Did you change the layer height? Did you change the line count? A 0.8 mm nozzle standard width line can replace two 0.4 mm nozzle lines.
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The first question I would ask: Did you perform a max flow calibration?
The reason I ask that is that I did find that the Bambu predefined filament profiles for 0.8 were far off from what I calibrated manually. The max flow variable will factor into how fast the slicer moves the nozzle in G-code.
The second element is speed. There isn’t really a good calibration routine for that because there’s more to speed than just the nozzle movement. As an example, nozzle backpressure due to filament abrasiveness can influence the performance. So you have to dial that in via trial and error.
I had greatest success with HF PETG filaments. It seemed to really stand up well to both layer adhesion and minimal artifacts. Elegoo Rapid PETG outperformed Bambu HF in my tests and at the time, Bambu was still asking nearly $30/spool whereas Elegoo was offering next day delivery on their Rapid PETG for less than half that on Amazon.
An don’t forget that you have high speed settings on the printer too.
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Speed depends on a lot of factors. As one random example, on a part with quick layer times, the whole layer may be slowed down for better cooling.
Here’s an example of .6mm vs. .8mm I posted earlier, demonstrating a clear time difference based on nozzle size and line width (not same printer, I know, but the settings still apply). Should I get .08 Vortek hot ends to save time or .06 first? - #10 by MaxThreeD
-Max
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Exactly what @EnoTheThracian said!
Some more elaborate details:
The size of the orifice is not the limiting factor but the ability to melt plastic fast enough. And for the X1C in stock configuration it’s also not the power of the heating element but the ability to transfer the heat fast enough into the filament, so that it is fully melted also in the center / core.
A HF nozzle solves this by heating not only the outside but alse the core by splitting the filament into 3 smaller strands that get heated individually and join again before the orifice. In effect, a 0,4mm HF nozzle achieves much higher throughput than a 0,6 or 0,8mm standard nozzle. And you can easily print 0,8mm wide lines with a 0,4mm nozzle. So for me, the only reason to use a bigger nozzle is printing filament with particles like CF, glow in the dark or wood filled filament.
For the standard 0,4mm nozzle, the max flow setting in the bambulab filament profiles of ~ 20 mm³/s is almost a bit optimistic in my opinion. While it still prints visually fine, layer adhesion ( how much force is needed break layers apart) already takes quite a hit of 20-30% according to my measurements for PLA and PETG.
The BambuLab HF profiles on the other hand are very conservative in my opinion at I think 30 mm³/s.
The E3D HF nozzle produced parts with equal strength up to 20 mm³/s and printed visually fine at at > 40 mm³/s for PLA and PETG. I didn’t test any faster, because I didn’t see much practical use in it. You already have to tweak several parameters at once to make the printer achieve such high flow. And my layer adhesion test doesn’t work at higher flow, because the printer hardly achieves the needed speed before it has to decelerate again at the next corner.
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Another small consideration not posted yet is that when you use a 0.8mm nozzle, with less than 100% infill, generally your total material usage goes up. You lose resolution that allowed the slicer to sneakily add voids and non-printed areas. So it just throws more plastic in general which eats into the efficiency gains.
If your part is 200g+ that’s when bigger nozzles really tend to shine without messing too hard on settings. It’s just so many molecules to fill!
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