The default nozzle diameter for most of today’s printers is 0.4 mm, and the nozzles used in Original Prusa i3 MK3S+ and the MINI printers are no exception. Changing the nozzle takes just a few minutes and it can bring a number of benefits. According to our survey, only approximately 20 % of users tried replacing their printer’s nozzle at some point, which is quite a low number. Let’s look at how changing the nozzle can improve your experience.
A smaller nozzle is great for detailed (but slower) prints, while larger nozzles print faster, but the quality suffers – or does it? In reality, it’s a bit more complicated. In our article, we will demonstrate the benefits of smaller and larger nozzles in real situations. But first, we need to clarify something users often get wrong – the correlation between layer height and nozzle diameter.
Layer height vs nozzle diameter
Layer height should not exceed 80 % of the nozzle diameter. If you are using the standard 0.4mm nozzle, the maximal layer height is about 0.32 mm. However, with a 0.6mm nozzle, it’s possible to achieve up to a 0.48 mm layer height.
Apart from these limitations, the two parameters are independent of each other. Tweaking their settings separately will bring completely different results. The nozzle diameter affects the overall level of detail almost exclusively in the horizontal plane (parallel to the print surface). What does this mean? With a smaller nozzle, you will be able to print a more detailed text – assuming it’s placed on the top side of the printed object. Contrary to that, the layer height affects the level of detail on vertical and slanted sides of an object. You have a much greater chance of seeing individual layers on organic-looking objects. The lower you set the layer height, the better the overall result. On the other hand, it makes little sense to print rectangular-shaped objects with very low layer height. There will be little to no difference in the end result, plus the printing time will be unnecessarily long.
Print up to 4 times faster!
3D printing is not exactly a fast process. Even a print that is just a few inches tall can take several hours to complete. So it’s quite puzzling how overlooked large-diameter nozzle printing is, despite the fact that it can lead to a dramatic improvement of the printing speed.
STL download link – Chibi Grim by Tanya Wiesner
A larger-diameter nozzle lays down wider perimeters, which means that it uses fewer perimeters than a smaller-diameter nozzle to print a wall of the same thickness. A nozzle with a larger diameter also allows for printing with increased layer height. Combining these two effects leads to a noticeably shorter print time. There’s a catch, though: if you keep the same layer height to print something with just one perimeter, like a vase, you won’t notice any improvement in speed. Because the nozzle has to go through exactly the same sequence of moves, independent of diameter. Yes, the vase will have a slightly thicker wall, but the print time will be almost the same.
Effect on mechanical properties
Another advantage of using larger nozzles is the increased toughness of printed objects. An impact resistance test revealed that the objects printed with the 0.6mm nozzle absorbed up to 25.6 % energy more than those printed with a 0.4mm nozzle. And objects printed with a 0.25mm version absorbed 3.6 % less energy than those printed with a 0.4mm nozzle. This test was performed on ten different samples. We then removed the minimum and maximum values, which is why you can see values of 8 samples. To learn more about the Charpy impact strength test, please visit this link.
Supports
Supports are usually printed as a one perimeter wide polyline. If you go to slicer settings, you may often notice that the supports are deliberately underextruded, so they are easier to remove. And, of course, using a different printer nozzle directly affects the width of support walls. You can turn this into an advantage. By simply using a smaller nozzle supports will be thinner and easier to remove. Using larger nozzles has an opposite effect leading to wider and sturdier supports, which can be a bit difficult to remove.