With the introduction of the Ultimaker 3, Ultimaker has shifted away from swappable nozzles in favor of interchangeable print cores. There are different print cores available, depending on what you're looking to do.
Generally speaking, the AA print cores are intended for all non-abrasive build materials, such as PLA, ABS, Nylon, etc. The BB print cores are exclusively for use with PVA water soluble support material. And the CC print cores are intended for use with abrasive build materials, such as carbon-fiber reinforced materials, glass-fiber reinforced materials, or metal-infused materials.
Each Ultimaker 3, Ultimaker 3 Extended and Ultimaker S5 includes two of the AA 0.4mm print cores and one of the BB 0.4mm print cores in the box. This allows you to print with two build materials (i.e. two colors of PLA) or to print one build material with PVA water soluble supports.
Print cores can be mix-and-matched to a certain extend to achieve your desired results. For example, you can use a AA 0.4mm print core along with a BB 0.8mm print core if you like. As long as both print cores are selected correctly in Ultimaker Cura and the layer heights are the same, it will work fine. However, the AA 0.25mm print core cannot be combined with the BB 0.8mm print core. This has to do with the layer heights. The 0.25mm print core is only supported for 0.1mm layer heights. The 0.8mm print core is only supported for 0.2mm, 0.3mm, and 0.4mm layer heights. Because they have no layer heights in common, they cannot be printed together.
The AA print cores are available with a 0.25mm nozzle, a 0.4mm nozzle, or a 0.8mm nozzle. The BB print cores are available with a 0.4mm nozzle or a 0.8mm nozzle. The CC print cores are available only with a 0.6mm nozzle.
Generally speaking, using a smaller nozzle will allow you to print finer details at the expense of reduced printing speed. Larger nozzles will allow you to print more quickly when print quality is not a top priority. With any given print core/nozzle combination, you can set the layer height to be about 75% of the nozzle diameter or less. So with a 0.8mm, you can use a layer height of up to 0.6mm. With a 0.4mm nozzle, you can use a layer height of up to 0.3mm. By using thicker layers, you can complete prints in significantly less time than would otherwise be possible, making it a good option for draft prints and initial prototypes.
The following is the full list of available Ultimaker Print Cores and their uses:
- Ultimaker Print Core AA 0.25mm: The Print Core AA 0.25mm allows for printing finer details (at the expense of reduced printing speed). This is especially helpful for parts with very thin walls or small extruded text.
- Ultimaker Print Core AA 0.4mm: The Print Core AA 0.4mm is the standard print core for build materials such as PLA, ABS, Nylon, etc. The 0.4mm nozzle offers a good balance of speed and quality.
- Ultimaker Print Core AA 0.8mm: The Print Core AA 0.8mm is a good option for high-speed printing. Using this print core, you can configure the layer height to be as much as 0.6mm, resulting in fewer layers and a significantly reduced printing speed. When using thicker layers, the layers will be more visible in the final print, so use this approach when the highest quality isn't needed.
- Ultimaker Print Core BB 0.4mm: The Print Core BB 0.4mm is intended ONLY for use with PVA water soluble support material. The internal shape of the nozzle on this print core is different, resulting in improved performance for the PVA material.
- Ultimaker Print Core BB 0.8mm: The Print Core BB 0.8mm is intended ONLY for use with PVA water soluble support material. The 0.8mm nozzle allows for faster printing by using thicker layers for printing PVA supports. Since the PVA supports will be removed after the print is completed, this is a good way to increase printing speed without sacrificing print quality for the printed object itself.
- Ultimaker Print Core BB 0.6mm: The Print Core Red CC 0.6mm is designed specifically for printing abrasive composite materials, such as carbon-fiber reinforced materials, glass-fiber reinforced materials, or metal-infused materials. This new print core contains a highly wear-resistant ruby cone tip that has a 1,000 hour life span, which equates to approximately 10 kg of carbon fiber-filled material. The new Print Core CC Red 0.6mm is specifically designed to be used with the Ultimaker S5. The feeder components in the Ultimaker S5 are fabricated from hardened steel, so it is designed to withstand more "punishment" than its earlier generation Ultimaker siblings. The Print Core CC Red 0.6mm can be used with the Ultimaker 3 or Ultimaker 3 Extended, but doing so is not officially supported by Ultimaker and may cause wear on the feeder, which would not be covered by the printer warranty. Users choosing to use the Print Core CC Red 0.6mm with an Ultimaker 3 or Ultimaker 3 Extended will receive a compatibility warning that will need to be overridden before printing will proceed.