How to Prevent Clogging in 3D Printers - Slice Engineering's Ultimate Guide

How to avoid clogging?

All hotends can clog at times, and all-metal hotends can be more prone to clogging with PLA. However, there are a few things to check to ensure that clogging is minimized:
  1. Airflow direction: The hotend cooling fan can be positioned on either side of the heat sink, but it must face the heat break. Meaning, airflow should be directed (“pushed”) toward the heat break, NOT pulled through it. 
  2. Retraction settings: For direct drive extruders paired with the Mosquito® series of hotends, we recommend setting your retraction to the same distance as the diameter of the nozzle you are printing with. Ex: when printing with a 0.4 mm nozzle, set the retraction distance to 0.4 mm in your slicer. For Bowden setups, the length of the Bowden tube heavily influences necessary retraction lengths and will require some tuning. We recommend halving the retraction setting used with your previous hotend (before Mosquito® installation) and tuning from there
  3. Thermistor calibration: The thermistor (temperature sensor) on your printer is dialed in with your printer’s control board. When installing any new thermistor, including Slice’s High Temperature Thermistors, you will need to ensure the proper settings are input into your firmware, and should run a PID tune on your controller. The RT tables for the Slice High Temperature Thermistors are available here. Duet3D and Marlin 2.0 and above natively support the Slice High Temperature Thermistors. For Duet3D, select the "Slice Engineering High-Temperature Thermistor" for the 450°C thermistor and select  "Semitec 104-GT2" for the 300°C thermistor.  For Marlin, select Thermistor #67 for the 450°C thermistor and Thermistor #5 for the 300°C thermistor. We are constantly working with other firmware developers to include the Slice thermistor out of the box.
If you do experience a clog, the simplest way to clear a clog in the heat break of any all-metal hotend is to perform a cold pull or atomic pull. If that doesn’t work, the Mosquito® hotend has been designed with high temperature materials in mind. Simply disassemble the Mosquito® by following the instructions here.

It's possible to incinerate the residue of most printed plastics adhered to our hot blocks, heat breaks, and nozzles in a kiln set to 500°C.  The combustion gases must safely vent to a laboratory fume hood featuring HEPA and active carbon filtration because they're likely toxic.  Discoloration of metal surfaces will occur.  Never perform this procedure in a kitchen oven or with any equipment used for food preparation.  Performing this procedure on any components besides those listed above will result in their destruction.

Place the hot block and heat break into an oven at 500 °C, and burn out the plastic. Please do not put the heat sink in the oven. It will deform. Also, please do not burn yourself!