There are many parameters to take into account in order to ensure the success of your 3D printing. FDM or FFF 3D printers use nozzles for extruding filaments to manufacture your 3D parts. Here we will see the essentials of what you need to know about 3D printing nozzles.
3D printer nozzle materials
brass nozzles
Brass nozzles are the most used nozzles in 3D printing because they are inexpensive and can be used with most filaments such as PLA, ABS, ASA, PETG, nylon etc…
Brass nozzles are also ideal because brass has a very good thermal conductivity but it wears out quickly and it is therefore not recommended to use brass nozzles to print abrasive filaments such as filaments filled with carbon fibers.
Maximum temperature of brass nozzles: 300°C
Advantages of brass nozzles:
Thermal performance and low price
Disadvantages brass nozzles:
Low wear resistance and not suitable for abrasive materials
Stainless steel nozzles
Stainless steel nozzles allow the 3D printing of corrosive filaments (not to be confused with abrasives) and also the printing of parts for the food or medical field because stainless steel nozzles do not contain lead like brass nozzles. They are also suitable for abrasive filaments for small uses.
They also allow a good compromise in terms of price between brass and hardened steel.
As stainless steel has a lower thermal conductivity than brass, you will need to heat your nozzle a little more. It is also preferable to slightly lower your printing speed for optimal use.
Maximum temperature of stainless steel nozzles: 350°C
Advantages of stainless steel nozzles:
Better wear resistance than brass and can be used for food filaments
Disadvantages of stainless steel nozzles:
Lower thermal conductivity than brass nozzles and lower wear resistance than hardened steel nozzles.
Nickel plated copper nozzles
Copper is a metal with very high thermal conductivity. Compared to a brass nozzle, copper offers three times the conductivity. The copper offers better temperature stability when printing and the nickel protection reduces the sticking of the filament inside the nozzle. The nickel-plated copper nozzles also achieve printing temperatures of 500°C.
Maximum temperature of copper / nickel nozzles: 500°C
Advantages copper / nickel nozzles:
High thermal conductivity, versatility, wear resistance superior to brass nozzles.
Disadvantages copper / nickel nozzles:
Lower hardness than hardened steel and not suitable for regular use with abrasive filaments
Hardened steel nozzles
The hardened steel nozzles allow the printing of charged filaments such as filaments with glass fibers, carbon fibers or Kevlar fibers. Hardened steel nozzles have ten times the resistance of a brass nozzle.
Steel has a low thermal conductivity, you will need to increase your printing temperature.
Maximum temperature of a hardened steel nozzle: 500°C
Advantages of hardened steel nozzles:
High wear resistance and durability with abrasive filaments
Disadvantage of hardened steel nozzles:
Low thermal conductivity and print quality may decline
Ruby Nozzles
Ruby nozzles, whose tip of the nozzle is made of ruby, offer very high wear resistance and very good thermal conductivity thanks to its brass body.
The ruby nozzle with brass body is a very interesting nozzle for abrasive filaments offering a very good thermal conductivity / durability ratio.
Maximum ruby nozzle temperature: 500°C
Advantages of ruby nozzles:
Good thermal conductivity, high wear resistance and resistance to high printing temperatures.
Disadvantages of ruby nozzles:
High price
The diameters of 3D printing nozzles
3D printing nozzles exist with different diameters from 0.2mm up to 1.2mm. These differences in diameter will allow prints with different accuracies and printing speeds.
Nozzles from 0.2 to 0.4mm
The small diameter nozzles allow 3D prints with very good precision. The disadvantage is that the small diameter nozzles are used with low layer heights to increase the print quality which will increase your print time although this parameter also depends on the settings of your slicing software. .
0.5 and 0.6mm nozzles
The nozzles with a diameter of 0.5 and 0.6mm allow satisfactory results in terms of print quality and also save printing time.
Nozzles from 0.8mm
Nozzles with an exit diameter equal to or greater than 0.8mm allow faster prints but lead to a decrease in the precision of the details of your 3D prints.
These large-diameter nozzles are to be used for large-volume 3D printing and not having the objective of manufacturing aesthetic parts.
The case of Volcano and Super Volcano nozzles
Volcano or super Volcano type nozzles are longer nozzles and their design allows a larger amount of filament to be heated and therefore to be used with faster printing speeds than standard nozzles.
LLayer heights as a function of nozzle diameter
In order to make a solid part, the adhesion between the layers must be perfect.
To do this, you need to calculate the minimum or maximum layer height depending on the diameter of your nozzle.
The rule is very simple, the minimum layer height is 25% of the nozzle diameter and the maximum layer height is 80%.
Example for a 0.4mm diameter nozzle:
Maximum layer height: 0.4 x 0.8mm = 0.32mm
Minimum layer height: 0.4 x 0.25mm = 0.1mm
The shell thickness of 3D prints
The shell thickness (outline, top solid layers, and bottom solid layers) of your 3D print will necessarily be a multiple of the outlet diameter of your nozzle.
For most 3D applications, a shell thickness of 0.8mm will be sufficient, i.e. 2 contours with a standard 0.4mm diameter nozzle. But if you use a nozzle with a diameter of 0.8mm then you will save a lot of printing time because the nozzle will only need to pass once!
For mechanical applications, it is necessary to use a minimum shell thickness of 1.2mm and play on the percentage of internal filling in order to have the strongest part possible.
Real-world example of print speed as a function of nozzle diameter, layer height, and shell thickness
Example with a 50x50x50mm calibration cube
1is test: standard nozzle of 0.4mm and layer thickness of 0.2mm (shell 0.8mm) (Speed 40mm/s) filling 25%
3D printing time (Simplify 3D): 4 hours and 51 minutes
2nd test: standard nozzle of 0.8mm and maximum layer thickness of 0.64mm
3D printing time (Simplify 3D): 56 minutes
3rd test: 0.8mm volcano nozzle and maximum layer thickness of 0.64 + speed increased by 50% or 60mm/s
3D printing time (Simplify 3D): 39 minutes