Glossary · Design

3D printing

Direct drive

The drive for the plastic filament sits directly on the print head. This also lets soft, rubbery materials print well.

Explained in more detail

Short filament path between drive gear and nozzle. Advantages: precise retractions with short retraction (0.5 to 2 mm) and reliable feeding of flexible filaments such as TPU. Disadvantage: more moving mass on the print head. This used to limit speed, but light extruders and input shaping now largely compensate for it. Standard on almost all new printers.

Where does the term come from?

The name says it: the extruder drives the filament directly at the hotend, without a long tube in between.

In practice

• Typical retraction: 0.5 to 2 mm at 30 to 45 mm/s. More retraction rarely helps and can clog the nozzle.
• You can tell whether your printer has direct drive by the fact that the motor for the filament sits on the print head and moves with it.
• Print TPU slowly: the base profiles of OrcaSlicer set only about 3 mm³/s volumetric flow for TPU.
• Because the head is heavier, input shaping is worthwhile on fast printers to reduce ghosting caused by vibrations.

Not to be confused

Direct drive describes only the filament drive, not the axes. A direct drive printer can also have a PTFE tube that guides the filament from the spool to the head.

Frequently asked questions

Can a Bowden printer be converted to direct drive?

Conversion kits exist for many common models. Afterwards you have to readjust retraction as well as E-steps or rotation distance and adapt the slicer profile.

Do you need direct drive for TPU?

Not necessarily, but it makes TPU much easier. With Bowden, harder grades at very low speed are more likely to work, while soft TPU buckles in the tube.