The Ultimaker 3, the Ultimaker S3, and the Ultimaker S5 make use of print cores. These come in several types and sizes. For an overview of print core and printer compatibility, please visit this page: What print cores are compatible with my printer?
Older generation print cores included a white or red nozzle ring. This ring must be removed before use with the Ultimaker S3 and S5, or with newer generation Ultimaker 3 print heads. The nozzle ring, when used in combination with the thicker, transparent nozzle cover, may prevent the print head fan bracket from closing properly. The thicker nozzle cover creates a tighter seal around the print cores with less space inside of the print head. This makes the nozzle ring redundant.
After thorough testing, Ultimaker has determined that even on older generation Ultimaker 3 print heads, the silicone nozzle rings are unnecessary.
|Old-style nozzle cover on the Ultimaker 3||New-style nozzle cover as used on the Ultimaker S3, S5, and later generation Ultimaker 3 print heads|
Caution: Using a print core that has a nozzle ring on the Ultimaker S5 may cause the fan bracket to fall open during printing, which can cause damage to your printer.
Note: It is also important that the outside surface of the nozzle is clean. Before inserting a used print core in the Ultimaker S3 or S5, ensure that there is no nozzle ring or filament residue on the print core.