The print core type DD is designed to be used with Ultrafuse® Support Layer material and is part of the Metal Expansion Kit (EU and select regions).
It is important to perform regular maintenance actions to keep the print core and print head in optimal condition. Because of some properties of the Ultrafuse® Support Layer material, the DD print core requires more frequent maintenance than other print core types.
This article details the frequency and type of maintenance that should be performed when using the DD print core.
Caution: When performing these maintenance actions, turn off the printer when possible, or ensure it is disabled in the UltiMaker Digital Factory to prevent new print jobs from starting remotely.
Clean the print core
The DD print core should be cleaned after every print, unless it will immediately be used again for the next print job. If you know the printer or the DD core is not going to be used for 24 hours or longer, or when unloading the DD print core print the print head, please clean the print core first. You should also clean the print core as corrective maintenance when you notice the nozzle is (partially) blocked or you see signs of under-extrusion.
Cleaning the print core can be done quickly and easily with the 'hot and cold pull' method. It is recommended to use UltiMaker cleaning filament, as this is the most effective material for cleaning the print cores.
In the menu on the display of the printer, open the Preferences menu (gear icon), then select Maintenance → Print head → Print core cleaning. Follow the instructions on the display, or visit this page for more information: How to perform a hot and cold pull.
Caution: It is never recommended to insert a needle into the nozzle tip to help unclog the print core. Especially do not use a needle on the DD print core. If the point of the needle touches the ruby, this can irreparably damage it.
Clean the nozzle
During printing, some material can sometimes stick to the outside of the nozzle and degrade. Although this will not damage your printer, it is recommended to keep the nozzle clean in order to achieve the best print results. Because the materials compatible with the DD core tend to stick to the nozzle more easily, cleaning the outer surface of the nozzle should be done more frequently than with the AA and BB print cores.
Before starting a new print, always clean the nozzle. The material can be removed from the outside of the nozzle by taking the following steps:
- On the printer's display, open the Configuration menu and select the print core you want to clean.
- Click on the icon in the top-right corner and select Set temperature.
- Use the controls to set the target temperature to 150 °C. Wait for the material on the outside to get soft.
- When the nozzle is hot, carefully remove the material with steel or brass wool, or a cloth.
- After cleaning, lower the temperature back to 0 °C.
Note: Do not use Scotch-Brite pads to clean the nozzle. This can cause slight wear on the outer part of the bottom of the nozzle. Do not use tweezers or anything sharp to clean the nozzle. This can damage the ruby insert.
Caution: This process requires working with a hot nozzle. Do not touch the nozzle during this procedure and be careful. Using personal protective equipment such as (thermal) gloves is advised.
Check the quality of the nozzle cover
Regularly checking the quality of the nozzle cover at the bottom of the print head is important. The nozzle cover shields the print cores from the fans' airflow and protects against backflow of material. Never start a print if the nozzle cover is missing, damaged, or worn.
The heat from the nozzles may cause the nozzle cover to wear over time. Normally, it is recommended to check the quality of the nozzle cover at least once every three months. When using the DD cores, it is recommended to check the cover at least once every month. This is equal to the recommended maintenance frequency for the CC cores, which are often used in combination with the DD core.
Examine the bottom of the print head to see if the holes where the nozzles come through are still round and not burnt, torn, or frayed. Ensure the cover still forms a good seal. Also gently open the fan bracket to check the other side of the nozzle cover. Learn more here: Check the S series nozzle cover
If the nozzle cover looks damaged, it must be replaced. Because of the increased wear when using the CC print cores, each CC print core comes with four spare nozzle covers. Learn how to replace the nozzle cover correctly on this page: Replace the S series nozzle cover
Removing broken material
If the material cannot be unloaded properly to perform all of these maintenance actions, or if you see the material is broken, the filament must be removed manually. It is possible that the material is stuck in a position that is hard to recover from.
Please read this guide for instructions on how to remove the material and proceed with the maintenance actions: How to clean the system if you can't unload material from the feeder
