What should retraction distance be?

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What should retraction distance be?

Set retraction distance to 0.7 to 0.8 mm on a direct-drive extruder: that is what Bambu Studio, PrusaSlicer and UltiMaker Cura ship for direct-drive printers with a 0.4 mm nozzle. On a Bowden extruder, start at 2.5 to 6.5 mm: Prusa’s MINI ships 2.5 or 3.2 mm, Cura’s UltiMaker S5 profile 6.5 mm. Then tune with a retraction test.

The number

Printer Extruder Slicer Retraction length Retraction speed
Bambu Lab X1 Carbon, P1S, P1P Direct drive Bambu Studio 0.8 mm 30 mm/s, 30 mm/s deretraction
Bambu Lab A1, A1 mini Direct drive Bambu Studio 0.8 mm, inherited from Bambu’s base profile 30 mm/s, 30 mm/s deretraction
Prusa MK4S Direct drive (Nextruder) PrusaSlicer 0.7 mm 35 mm/s, 25 mm/s deretraction
Prusa Core One Direct drive (Nextruder) PrusaSlicer 0.7 mm 45 mm/s, 25 mm/s deretraction
Prusa MK3S, MK3S+ Direct drive PrusaSlicer 0.8 mm 35 mm/s both ways
Creality Ender-3 S1 Direct drive UltiMaker Cura 0.8 mm 40 mm/s
Prusa MINI, MINI+ with Input Shaper firmware Bowden PrusaSlicer 2.5 mm 70 mm/s, 40 mm/s deretraction
Prusa MINI, MINI+ Bowden PrusaSlicer 3.2 mm 70 mm/s, 40 mm/s deretraction
UltiMaker S5 (2.85 mm filament, 850 mm tube) Bowden UltiMaker Cura 6.5 mm 45 mm/s, 15 mm/s prime

Every row is the 0.4 mm nozzle profile, read at a release tag and followed through its inheritance chain: Bambu Studio v02.08.02.61, the Prusa profiles bundled with PrusaSlicer 2.9.6, and UltiMaker Cura 5.13.0 (UltiMaker’s own PLA adds no override on the S5’s AA 0.4 print core). The S5’s tube length is from UltiMaker Support.

Why does a Bowden extruder need a longer retraction?

Because its drive gear sits on the frame, a whole tube away from the nozzle. The gear has to take up the give in all that filament before the tip moves. On a direct drive the gear rides on the print head just above the hotend, so only a short stretch of filament separates gear and nozzle.

Two things absorb the start of a Bowden pull-back:

  • Compression. Marlin’s Linear Advance docs model the free filament between gear and nozzle as a spring that is squeezed while printing, and list Bowden length among the things that change it. A retraction first lets that spring relax.
  • Room in the tube. Capricorn’s spec sheet puts ordinary PTFE (polytetrafluoroethylene) tubing for 1.75 mm filament at a 2.0 to 2.1 mm bore, so the strand has room to bend. Capricorn, whose XS tube has a 1.90 mm bore, says switching to it lets you reduce retraction.

Bondtech builds the tube into its recommendation for its original LGX Lite extruder: 0.4 mm for rigid filament on a direct drive, about 5 mm on a Bowden, worked out as 0.4 mm plus 0.015 mm for every millimeter of tube. Prusa gives the same reason for its MINI: the presets are “much longer” because of the Bowden extruder.

A Bowden tube cut open along its length, the filament bending inside a bore wider than itself on its way from the drive gear to the melt zoneBefore the filament tip leaves the melt zone, a Bowden extruder's gear has to take up the compression and the room to bend along the whole tube, which is why it needs a longer retraction than a direct drive.1Drive gear on the frame4Melt zone in the hotend2Bore wider than the filament3Filament bends and compresses along the tube
  1. Drive gear on the frame
  2. Bore wider than the filament
  3. Filament bends and compresses along the tube
  4. Melt zone in the hotend
Before the filament tip leaves the melt zone, a Bowden extruder's gear has to take up the compression and the room to bend along the whole tube, which is why it needs a longer retraction than a direct drive.

What is retraction distance?

The length of filament the extruder pulls back before a travel move so the nozzle does not ooze, measured on the raw filament before it enters the extruder. Set to 0, it turns retraction off. Bambu Studio labels it “Length”, PrusaSlicer “Retraction length” and UltiMaker Cura “Retraction Distance”.

How do direct drive and Bowden retraction settings differ?

A Bowden needs several times the length, and Prusa runs it faster. In Prusa’s profiles the Bowden MINI pulls back 2.5 to 3.2 mm at 70 mm/s, 3.6 to 4.6 times as far as the direct-drive MK4S and Core One at 0.7 mm and 35 to 45 mm/s.

Is my printer direct drive or Bowden?

Look for the drive gear, not for a tube. On Prusa’s MINI the extruder motor is fixed on the side of the frame and pushes filament through a Bowden tube to the print head. The Core One also feeds filament through a PTFE tube, but into the Nextruder on the moving carriage, so it is direct drive.

Does the filament change retraction distance?

Yes. A filament profile can override the printer’s length; in Bambu Studio that sits under Filament Settings, Settings Overrides. Starting values are on the PLA, PETG, TPU and ABS and ASA pages.

Is there a maximum retraction distance?

No universal one, but two makers set a line. Prusa says retraction length should be at most 2 mm on the MK2.5/S and MK3/S/+. UltiMaker Cura shows a warning once Retraction Distance passes 10 mm. Bambu Lab’s wiki gives no figure but warns that too much retraction causes under-extrusion and layer gaps, with some chance of a clog (signs it is too high).

How to check it on your own print

  1. Read what your slicer sends. Bambu Studio: Printer Settings, Extruder, “Length”, then the filament’s Settings Overrides, where a gray or N/A field means the printer value applies. PrusaSlicer: Printer Settings, Extruder 1, “Retraction length”. UltiMaker Cura: the Travel section, “Retraction Distance”.
  2. Dry the spool first. Bambu Lab says stringing from damp filament usually cannot be fixed by retraction settings alone.
  3. Print a retraction tower. OrcaSlicer’s Retraction test defaults to 0 to 2 mm in 0.1 mm steps for direct drive. For a Bowden, its wiki suggests 1 to 6 mm in 0.2 mm steps (full calibration method).
  4. Pick the shortest length that gives the cleanest section, as OrcaSlicer’s wiki advises. Keep it under your maker’s ceiling, such as 2 mm on a Prusa MK3S.
  5. Save it where it belongs: in the printer profile if it fixes every filament, or as a filament override if only one spool strings.

Sources

  1. resources/profiles/BBL/machine/Bambu Lab X1 Carbon 0.4 nozzle.json at v02.08.02.61, Bambu Studio on GitHub (accessed October 30, 2026)
  2. resources/profiles/BBL/machine/Bambu Lab P1S 0.4 nozzle.json at v02.08.02.61, Bambu Studio on GitHub (accessed October 30, 2026)
  3. resources/profiles/BBL/machine/Bambu Lab P1P 0.4 nozzle.json at v02.08.02.61, Bambu Studio on GitHub (accessed October 30, 2026)
  4. resources/profiles/BBL/machine/Bambu Lab A1 0.4 nozzle.json at v02.08.02.61, Bambu Studio on GitHub (accessed October 30, 2026)
  5. resources/profiles/BBL/machine/Bambu Lab A1 mini 0.4 nozzle.json at v02.08.02.61, Bambu Studio on GitHub (accessed October 30, 2026)
  6. resources/profiles/BBL/machine/fdm_bbl_3dp_001_common.json at v02.08.02.61 (the base profile the X1, P1 and A1 profiles inherit), Bambu Studio on GitHub (accessed October 30, 2026)
  7. src/libslic3r/PrintConfig.cpp at v02.08.02.61, Bambu Studio on GitHub (accessed October 30, 2026)
  8. Retraction, Bambu Lab Wiki (accessed October 30, 2026)
  9. resources/profiles/PrusaResearch.ini at version_2.9.6, PrusaSlicer on GitHub (accessed October 30, 2026)
  10. src/libslic3r/PrintConfig.cpp at version_2.9.6, PrusaSlicer on GitHub (accessed October 30, 2026)
  11. Stringing and oozing, Prusa Knowledge Base (accessed October 30, 2026)
  12. Extruder / Extruder motor (MINI), Prusa Knowledge Base glossary (accessed October 30, 2026)
  13. MK4S glossary, Prusa Knowledge Base (accessed October 30, 2026)
  14. CORE One glossary, Prusa Knowledge Base (accessed October 30, 2026)
  15. resources/definitions/ultimaker_s5.def.json at 5.13.0, UltiMaker Cura on GitHub (accessed October 30, 2026)
  16. resources/variants/ultimaker_s5_aa04.inst.cfg at 5.13.0, UltiMaker Cura on GitHub (accessed October 30, 2026)
  17. ultimaker_pla_black.xml.fdm_material at 5.13.0, UltiMaker fdm_materials on GitHub (accessed October 30, 2026)
  18. resources/definitions/creality_ender3s1.def.json at 5.13.0, UltiMaker Cura on GitHub (accessed October 30, 2026)
  19. resources/definitions/fdmprinter.def.json at 5.13.0, UltiMaker Cura on GitHub (accessed October 30, 2026)
  20. Creality Ender-3 S1 Review: A Direct Drive 3D Printer for DIY Enthusiast, Creality blog (accessed October 30, 2026)
  21. PTFE Bowden tube for UltiMaker TPU 95A, UltiMaker Support (accessed October 30, 2026)
  22. Linear Advance, Marlin Firmware documentation (accessed October 30, 2026)
  23. Technical Specifications, Capricorn Bowden Tubes (accessed October 30, 2026)
  24. Frequently Asked Questions, Capricorn Bowden Tubes (accessed October 30, 2026)
  25. LGX Lite eXtruder (without motor), technical specification, Bondtech (accessed October 30, 2026)
  26. Retraction test, OrcaSlicer Wiki (accessed October 30, 2026)