One of the most basic things to underamstand about 3D printing is the relationship between layer height vs nozzle size. While the two values are related, they’re not the exact same thing!
When I got my first 3D printer, I thought that a 0.4mm nozzle meant I could use a 0.4mm layer height. Boy, was I wrong! I ended up with a clogged nozzle on my first ever 3D print and that was not a fun experience!
In this post, we’ll talk about both of these values and clarify what they are, as well as how they are used together in 3D printing.
Relationship between layer height and nozzle size
As a general rule, your maximum layer height should be 75% of your nozzle size. For most consumer-grade 3D printers that ship with 0.4mm nozzles, you can use a maximum layer height of 0.3mm. The minimum layer height is between 12-25% of your nozzle size. On a 0.4mm nozzle, you can go as low as 0.1mm, but some 3D printers can manage 0.05mm as well.
Layer heights to use
So what layer heights should you use? You’ll find that there are 3 values that you bounce between for most of your 3D printing. There will be a small extreme, a high extreme, and a middle.
For everyday 3D printing, you’ll probably use the middle value. This is what you’ll need for 3D printer mods, test prints, and even functional prints that don’t require much detail.
For 3D printers that have 0.4mm nozzles, this will be a 0.2mm layer height.
Actually, you can just set your layer height to 0.2mm and just forget about ever adjusting the value again! 0.2mm works for most applications.
0.2mm layer heights will show some layer lines, but they won’t be very visible unless you look closely.
It’s only when you want to get highly detailed prints(such as miniatures) that you can go to smaller layer heights.
When to use small layer heights
It may be tempting to always use small layer heights. After all, who doesn’t want their 3D prints to look as best as can be?
When you need highly detailed prints, lower layer heights such as 0.1mm and below are ideal. Some 3D models have very minute details that may not print correctly at larger layer heights.
If you’re into tabletop games and are making miniatures, 0.1mm and lower will give you the detail and resolution that you are looking for.
The biggest drawback of small layer heights, however, is that they take VERY long to print. The time required to print a model more than doubles every time you halve the layer height.
When to use large layer heights
Large layer heights are useful for quick prototyping 3D prints. They’re also ideal for very big models that don’t require much detail.
The advantage to using large layer heights is that you can print very quickly. With a 0.4mm nozzle, you can go up to a 0.3mm layer height and complete taller prints much quicker.
Large layer heights won’t result in the prettiest prints, and the layer lines will be very visible. Still, if it’s function you’re after and not form, 3D prints done with large layer heights are just as strong.
What about extrusion width?
Another factor that comes into play(but is not discussed much) is extrusion width. While layer height determines how high each layer will be, extrusion width determines how wide each layer is.
Normally, you can leave this value at the default setting in your slicer.
If you do decide to play around with it, remember that the same rule applies: the maximum extrusion width is 75% of your nozzle diameter.
If you exceed that number, you’ll end up with a clogged nozzle, as you can’t push out thicker filament than your nozzle allows!
Most consumer-grade 3D printers ship with a 0.4mm nozzle. This is pretty standard, and a 0.4mm nozzle is suitable for a very wide range of applications.
You only really need to change the nozzle if you’re planning on printing super small or super large.
Using the 75%/25% rule above, you can calculate how much smaller or larger your layer height can be depending on the nozzle you use.
However, remember that your extruder’s stepper motor and your 3D printer’s mainboard have to be able to handle very small details if you’re going to go with tiny layer sizes.
The nozzle is just part of the equation, and the heigh of the extruder filament depends on how fast or slow the extruder pushes the filament out.
You also need to consider Z-steps. If your stepper motor can only turn a minimum of 0.1mm, then each layer will have to be that much higher than the previous one for best results. You’ll also need to factor in the leadscrew. To learn more about this, check out our post on magic numbers.
While we’re on the topic of nozzles, it’s worth talking about nozzle materials. Nozzles are commonly found in brass and stainless steel varieties.
Brass nozzles are cheaper and come stock on most 3D printers. You can also upgrade to a stainless steel nozzle if you plan on printing with abrasive or high-temperature filaments.
Brass is comparatively softer than stainless steel, so if you plan on printing a lot of abrasive filaments like carbon fiber, or metal-fill, it would be worth investing in a steel nozzle.
Otherwise, the prolonged printing will slowly eat away at the brass nozzle.
Print times with varied layer heights and nozzle sizes
For this example, I’ve used a standard XYZ calibration cube.
|Nozzle size||Layer Height||Print time(hours)|
Nozzle size and layer height are two very closely related values. Layer height is dependant on nozzle size, so depending on how much or how little detail you want, you will need to adjust these values to get the resulting 3D print you are looking for.