3D Printing - feliyur/exercises GitHub Wiki

Printer: Creality Ender 3 v2. First glass, then PEI flexible magnetic surface.

Under- or over-adhesion

Using high nozzle and / or bed temperature makes the filament easier stick but may cause difficulties to remove the part later - it's a tradeoff. To make removing easier use painter's tape or glue stick.

This is particularly severe for extremely thin prints - e.g. bed level test. The PLA can practically fuse with the surface. Use lower temperatures for bed level test.

Useful software and websites

Name Function
Cura slicer
onshape online 3d design
OctoPrint printer remote control with a web gui interface. Note that for being able to resume a paused print on ender need to adjust settings. Consider running in a docker container.
Thingyverse public 3d models

Clogged Extruder

Symptom: stringy, uneven extrusion - filament comes out as a thin string with periodic slightly thicker bumps. This often happens if the filament has spent too long in a humid environment.

Troubleshooting: "Cold pull" procedure to remove the blockage

Note: Should always make sure that the filament is in good condition. If it caused clogging better to switch to a new(ly opened) roll or dry it before attempting the below procedure.

  1. Preheat the extruder.
  2. Push the filament in such that it starts coming out from the other side
  3. Cool the nozzle down to room temperature
  4. Heat the nozzle back up to 70-90 deg celsius (PLA/PLA+).
  5. Pull the filament out. If it doesn't come out, heat the nozzle up by 10 degrees and repeat, until it comes out.
  6. Repeat, until the symptoms resolved.

Printing Tips

  • Use precise measurement tools when fitting parts, e.g. a digital caliper.
  • Allow tolerances in your measurements, 0.2 mm works well in Ender.
  • Print smaller test prototypes, especially for larger parts that consume a lot of filament (and time).
  • Don't allow filament to be in open air for too long or else expect problems. Dry it before use if it sits for too long (for out-of-the-box PLA filament, could be as low as 3 weeks). Filament drying devices do an excellent job.
  • Height resolution tends to be better, consider orienting finer features vertically.

Troubleshooting / diagnostics

Symptom Cause
Parts of print missing - filament doesn't stick Bed leveling - gap too large
Filament layer appears thin, extruder seems to scratch off some filament Bed leveling - gap too small
Filament doesn't stick Bed leveling, or greasy surface, or raise bed level temperature (don't overdo, can cause especially thin prints to be difficult to remove).
Filament comes out extremely thin, print completely stringy Clogged extruder? Possibly old / faulty filament - see above.