Nozzle Size: 0.4 versus 0.6

Just watched a YT video by Thomas Sanlander that recommends using a 0.6mm nozzle rather than the “standard” 0.4mm, especially with the new Cura Arachne slicer software. I’m somewhat of a newbie so any help with this question appreciated. My question: How does the slicer know what size nozzle is in the printer, or does it not need to know? I can’t find anywhere in Cura 4.11 or Luban that allows the user to specify nozzle size. Help please; thanks!

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There is a setting in Cura for it, although I don’t remember exactly where it is. Luban expects a 0.4mm nozzle and lacks the setting as of the last version I checked.

And yes, the slicer does need to know. The diameter of the nozzle opening affects how much plastic is pushed out (and therefore the width of each line laid down) and how small the smallest feature the machine can print is. Moving to a 0.6mm nozzle will allow you to print a bit faster, but slightly reduce the level of detail in the resulting models.

This is basically the main point of the Thomas Sanladerer Video: With the Arachne slicing library you achieve nearly the detail of a .4 mm nozzle (“old” slicing method), but with a .6 mm nozzle, while still harvesting the speed advantage. That said, a .4 mm nozzle with Arachne will be able to get better in detail than a .6 mm nozzle still. Tom’s point is: usually the “old” .4 mm slicing/printing results were good enough for most use cases - so why not have faster prints?

Thomas Sanladerer researches his stuff thoroughly, so I tend to believe him here, and the video is listing some facts that make the claim very much credible.

I seem to remember that in Cura the nozzle diameter is defined under “manage printers” and there under the extruder settings. may be wrong here however.

Fun fact: A SM2 A250 has a very short guest appearance in the video :slight_smile:

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You are correct. Settings > Printers > Machine Settings > Extruder.

I’ve also seen something on the Forum that indicates that Luban will get support for 0.6mm nozzles. IIRC, it was a drop down, only allowing 0.4mm and 0.6mm. I don’t remember where I saw it though.

Thanks for the link @Hauke !

Edit to add: The Artisan product page mentions 0.2, 0.4, 0.6, and 0.8mm nozzles. So I expect Luban will support them all eventually. With the dual extruder supports in Artisan, it might even support them at the same time.

I was in the livestream when he was testing the laser and CNC, I felt special when he gave me a shoutout during them. :smiley: Also I’ve been testing the Arachne engine in Prusaslicer, though not on my snapmakers. My Prusa machines are my main printers.

Although a lot of people claim so, I still am not convinced that a 0,6mm nozzle has any benefit on a Snapmaker. Line width and layer height can go up to 200% and 80% of the nozzle size respectively. So for a 0,4mm nozzle, that’s 0,8mm line width and 0,32mm layer height. The 2.0 print head has a maximum volumetric flow of about 9 cubic mm/s which yields a maximum print speed of 9/(0,8 * 0,32) = 35mm/s. I print with those settings without quality issues, so it’s not clear to me why a 0,6mm nozzle would be beneficial.
On the other hand, the new dual nozzle reportedly has a volumetric flow of 20 cubic mm/s, so for that one a 0,6mm nozzle does make sense.

At 200%, excess filament will be extruded in all directions around the nozzle. At this time, the filament may not be evenly distributed. It will cause dimensional errors and a reduction in shape.

I adjust the dimensions of what I make by 0.1 mm or less. When printing larger items, a 0.6mm nozzle is very useful.
The required accuracy varies depending on who prints and what they make.

If printing speed is important, printing at 0.8mm 100% is better than printing at 0.4mm 200%.

I think it would be a mistake to multiply the nozzle diameter by the height.

Is that an assumption, or your actual experience? I only print functional parts, and I have no quality or dimensional issues printing at 0,8mm line width and 0,32mm layer height with the stock 0,4mm nozzle. Then again, I consider +/- 0,1 mm accuracy reasonable for 3D printed parts.

I think for a lot of parts, printing at 200% is an overlooked possibility. It’s very easy to try, just by changing a few slicer parameters. Whereas changing the nozzle is more involved and also requires to change those parameters.

The formula is Volumetric flow [mm³/s] = line width [mm] x layer height [mm] x print speed [mm/s]

Hence: Print speed [mm/s] = Volumetric flow [mm³/s] / ( line width [mm] x layer height [mm] )

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Personally I’m skeptical of your analysis and claimed results, but post some pics… proof is in the pudding.

Well, the nice thing is that no one needs to believe anything, as everyone can just try it on a test part and see if the results suit their purpose or not.

Cura profile:
Volumetric flow 9mm³ per (766 Bytes)

Also: I’m not saying this is the best option for everyone and every case, but imo it is for sure worthwhile to give this a try before going through the trouble of swapping the nozzle.

I’d be very interested in someone actually posting a side-by-side comparison of a part printed with 0,8mm line width and 0,32mm layer height at 35 mm/s, one time with the stock 0,4 mm nozzle, and one time with a 0,6mm nozzle.

Anyway, the pics:

Below two examples, both in eSun PLA+. First example does not have a nice top surface, yet this is printed with just two top layers (as I’m optimizing for speed).
Second example has a better top surface: this is still printed with only two top surfaces but with the topmost skin layer printed at 0,4mm line width and 60 mm/s (so also close to 9 mm³/s). It yields a lot better result than the first example. Of course this could be further ameliorated by printing slower and/or with more top layers.

First example: bracket, about 15 cm long:

As said, the top side is not nice, but just two top layers:

Bottom side, imo. really nice :

Layers, imo also really nice:

Second example: side frame for a small conveyor belt, about 30 cm x 5 cm:

Top side, better, not perfect, but also just two layers of which topmost layer at line width 0,4mm@60mm/s:

Bottom side (imo acceptable, but bed calibration or z offset was a little bit off this time):


And this stepper motor holder plate is an example of PETG (3DJake). The mating surface between stepper and plate was sanded a bit to make it flat:

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That’s something I hadn’t considered. I have printed something with a 0.4mm layer height for prototyping. It’s not terribly strong, but it printed, was dimensionally accurate, and the layers didn’t separate.

Your method sounds even faster. I’ll give it a try next time I want something quick.

Cura 5.0+ uses the Arachne slicer by default now. It makes some questionable head movement at times, but it does render lines smaller than 0.4mm now.

The first time I printed Test your 3D printer! v3 by ctrlV - Thingiverse, it did not show the 0.1mm, 0.2mm, and 0.3mm walls in the preview, and didn’t print them. This time it shows them all in the preview. The preview also shows the narrow spire getting taller, but still not all the way to the point in the model. My guess is the slicer doesn’t try anything smaller than 0.1mm.

It printed… odd. The preview shows the distinct walls, but the actual print has a single continuous wall. I could hear a motor changing was the line was printed, but I don’t have digital calipers to see how accurately the print is. It seems like there’s some oozing that needs to be accounted for when printing narrower than nozzle features.

CHEP has a counter argument to Sanlander. Both make good points. I’m curious if anyone has made the optimizations Chuck discusses for the SM 2.

Chep missed the main point of Tom’s video, I think. Tom targets a broader range of users, aiming at the ‘general’ populace and is easy for beginners. He’s saying that the 0.6, with general/stock settings can now give equal if not better and faster than 0.4 for any user. Chep, on the other hand, is targeting the more advanced users, with advanced tuning of profiles you can achieve faster with 0.4, which is beyond the scope of a lot of beginners and even moderately savvy users. Feels like a “well just use what I made” kinda gloat.

Don’t take this as bashing Chep, not at all. They’re both excellent makers and provide a lot of valuable info to the community. It’s just different approaches. Tom aiming at a “this works for everyone” (since arachne is becoming default, the only onus is on the user to change their nozzle) and Chep is aiming at “but with tweaks and tuning you can get further” (well, seems to just be pushing his own profiles, but still the same point).


I have an 0.6 in my MK3S+ and printed some shelving at 0.48mm layers and they’re quite robust. As a fun check, this print took 5.5 hours, which with the 0.4 at 0.3mm layer would have taken 9 hours, and 0.4 @ 0.2 layer would have been 14 hours. I will say this, at the 350 level of snapmaker, that’s getting a biiiit big for an 0.4 nozzle, if you do something that fills most of the build volume, you’re gonna be spending days, if not a week. It should have come standard with an 0.6, or at least included one in the extra hotend to swap out.