One of the factors that affects print speed - the nozzle, as the last part in contact with the filament, has a significant impact on print time and quality.
The nozzle is the mechanical part of the 3D printer that extrudes the filament, and it conducts the heat provided by the heated cartridge and block to the filament, melting it. Three main features of the nozzle design are essential: size, material and internal diameter, all of the three nozzle features have an impact on the time that it requires to print the part and the quality of the final object.
Nozzles are classified as standard, volcanic, and super volcanic based on size. Standard is sized to fit V6 hot ends and MK8 extruders with a total length of 12 to 13 mm from the tip to the end of the M6x1 thread; Volcano hot ends are designed for higher speeds and higher temperatures and handle at least three times the filament of a normal V6 hot end, which has a longer nozzle, typically 21 mm from one end to the other, to promote a better heat transfer; and Super Volcano is a longer version of Volcano with a length that is nearly an almost absurd 50 mm of length.
The longer the length, the faster the melt rate, which means the faster print speed.
Nozzles are classified by material as brass, stainless steel, and hardened steel. Brass offers excellent heat transfer efficiency at a lower cost and can withstand temperatures up to 300°C, but it is not the most durable material and is highly susceptible to wear and tear. Although stainless steel and hardened steel can withstand temperatures up to 500°C, unfortunately, their heat transfer efficiency is not as high as that of brass. Therefore, brass is the most commonly used metal for 3D printer nozzles up to now.
The inner diameter of the nozzle affects the filament volume extruded per second, a characteristic called flow rate, which also determines the maximum extrusion speed. Nozzle diameters typically range from 0.1 mm up to 1.0 mm. The absolute standard for today's 3D printers is the 0.4 mm nozzle, which is available on almost all popular machines, and this diameter provides a good balance between speed and accuracy.
The recommended range of layer heights depends on the nozzle diameter to some extent. As a general rule, the maximum layer height value should not be more than 80% of the nozzle diameter. For example, the recommended maximum layer height for a 0.4 mm nozzle is 0.32 mm.
Larger nozzles usually reduce print time with higher extrusion flow, but sometimes it can also reduce print quality with problems such as stringing, scars on top surface, etc. Smaller nozzles can produce very detailed prints with almost invisible layer markings, unfortunately, it comes with reduced print speed and increased risk of clogging due to the small aperture size.
The different methods of consumable melting will also affect the filament melting rate and thus the printing speed to some extent.
As you can see, nozzle length, heat transfer efficiency of the nozzle material, and internal diameter are all closely related to print speed! If you want to print at high speed, the nozzle length should be at least 21 mm and the nozzle material should preferably be brass.within the right range,A larger inner diameter means higher print speed, but the print quality may not be as perfect, which will depend on your needs for quality and speed.