A 3D printer Bowden tube is a flexible tube that connects the extruder to the hot end. It allows the filament to be pushed and pulled by the extruder motor without bending or breaking. However, sometimes the Bowden tube can get clogged and cause printing problems. Here are some possible causes and solutions for a clogged Bowden tube:
- The filament is too soft or flexible. Some filaments, such as TPU or TPE, are very flexible and can bend inside the Bowden tube, creating friction and resistance. This can prevent the filament from feeding smoothly and cause clogging. To avoid this, use a stiffer filament or a direct drive extruder that eliminates the need for a Bowden tube.
- The filament diameter is too large or inconsistent. If the filament diameter is larger than the inner diameter of the Bowden tube, it can get stuck or jammed inside the tube. This can also happen if the filament diameter varies along its length, creating bulges or knots. To avoid this, use a high-quality filament that has a consistent diameter and matches the size of your Bowden tube.
- The Bowden tube is too long or bent. A longer Bowden tube means more friction and resistance for the filament to overcome. This can reduce the extrusion force and cause under-extrusion or clogging. A bent Bowden tube can also create kinks or pinch points that obstruct the filament flow. To avoid this, use a shorter Bowden tube that is as straight as possible and avoid sharp bends or twists.
- The Bowden tube is worn out or damaged. Over time, the Bowden tube can wear out due to friction, heat, or abrasion from the filament. This can create rough or uneven surfaces inside the tube that can snag or scrape the filament. A damaged Bowden tube can also have cracks or holes that can leak molten filament or allow dust and debris to enter. To avoid this, replace your Bowden tube regularly and inspect it for signs of wear or damage.