Good starting PLA retraction settings for Bowden tube printers are 5 mm of retraction at 40–60 mm/s, a slower 30–40 mm/s prime, wipe enabled, and Z-hop at 0.2 mm or off. From there, print a retraction tower from 1 to 6 mm in 0.2 mm steps and keep the shortest distance that prints clean.
Those numbers come straight from the stock profiles. OrcaSlicer’s shared Creality machine profile, which its Bowden Ender-3 V2 preset inherits, ships 5 mm at 60 mm/s with 40 mm/s deretraction. Cura’s base printer definition defaults to 6.5 mm at 25 mm/s. Prusa’s Bowden-fed MINI and MINI+ presets default to 3.2 mm. Your machine’s answer sits somewhere in that 3–6.5 mm band, and tube length, tube bore, the extruder and pressure advance decide where. Direct-drive numbers do not transfer: the Ender-3 V3’s stock PLA profile retracts just 0.6 mm.
Why does a Bowden tube need so much more retraction?
A Bowden extruder pulls from the far end of a tube, so the first few millimetres of every retraction only take up slack. The 1.75 mm filament snakes inside a bore nominally 2 mm wide, the strand compresses under feed load, and the push-fit couplers have play. Only once that slack is gone does the filament at the hotend move back and relieve melt-zone pressure.
That is why the clean distance on a Bowden machine is several times the direct-drive figure for the same PLA. Anything that removes slack shortens the distance you need:
- Tube bore. Capricorn XS tubing is specified at 1.9 ± 0.05 mm inside diameter. Around 1.75 mm filament, that cuts radial clearance from 0.125 mm in a true 2 mm bore to 0.05–0.1 mm. The vendor says lower retraction follows but publishes no figure, so retune after the swap.
- Tube length. Longer tubes add compliance, so a new tube or a relocated extruder makes the old value stale.
- E-steps. Retraction is commanded in millimetres of filament, so an extruder that under-feeds by 5% turns a 5 mm retraction into 4.75 mm. Fix that first with the e-steps procedure.
What should each retraction setting be?
For PLA on a Bowden printer: 5 mm distance, 40–60 mm/s retract, 30–40 mm/s prime, no extra prime, wipe on, Z-hop 0–0.2 mm and combing on. Change only distance until the tower says otherwise. Reference defaults are quoted from OrcaSlicer’s Creality profile, Cura’s base and Creality definitions, and the Prusa knowledge base.
| Setting | PLA starting value | Reference defaults | Notes |
|---|---|---|---|
| Retraction distance | 5 mm | Orca Creality 5 mm; Cura base 6.5 mm; Prusa MINI 3.2 mm | The only value the tower tunes |
| Retraction speed | 40–60 mm/s | Orca Creality 60 mm/s; Cura base 25 mm/s | Too high and the extruder skips steps |
| Deretraction (prime) speed | 30–40 mm/s | Orca Creality 40 mm/s | A slower prime keeps seam starts tidy |
| Extra prime on restart | 0 mm | Orca Creality 0 mm | Raise in tiny steps only if line starts are starved |
| Minimum travel before retracting | 1.5–2 mm | Cura 1.5 mm; Orca Creality 2 mm | Short hops don’t need a retract |
| Wipe while retracting | On, 70% retracted before wipe | Orca Creality on, 70% | Revisit once pressure advance is tuned |
| Z-hop | 0–0.2 mm | Cura Creality 0.2 mm when enabled; Orca Creality 0.4 mm | Lower lift strings less |
| Combing / avoid crossing walls | On | Cura Creality “Not in Skin” | Keeps travel inside the part |
| Max retraction count (Cura) | Keep default | Cura base 90 per 4.5 mm | Stops one stretch of filament being chewed |
| Nozzle temperature | Low-middle of the spool’s range | None | Prusa: drop 5–10 °C if strings persist |
Two traps hide in that list. Cura’s Creality definition switches combing off whenever Z Hop When Retracted is enabled, so turning on Z-hop to stop nozzle strikes quietly sends travel moves across open air and can add strings. Prusa’s warning about speed is real too: on a single-gear extruder, skipped steps show up as a click and a flattened, chewed section of filament.
PrusaSlicer keeps retraction under Printer Settings > Extruder 1 and Cura under Travel. In OrcaSlicer, put the PLA value in the filament profile’s Setting Overrides tab so a PETG profile on the same printer keeps its own.
How do you tune it with a retraction tower?
Run OrcaSlicer’s retraction test with a 1 mm start, 6 mm end and 0.2 mm step, the Bowden values in the OrcaSlicer wiki. That gives 26 levels. Hold speed, temperature and travel fixed, print it in the spool you will actually use, and take the shortest length whose section prints without strings.
- Finish the prerequisites. Retraction comes after filament condition, temperature, flow and pressure advance in the 3D printer calibration order, because each one changes how much ooze retraction has to cover. Dry the spool per the drying protocol, set temperature with a temperature tower, then calibrate flow.
- Generate the test. Calibration > Retraction test, start 1, end 6, step 0.2. OrcaSlicer’s default 0–2 mm range is built for direct drive and may never reach a Bowden machine’s clean band.
- Read it correctly. Find the cleanest section, measure its height, then search the G-code preview for the
Calib_Retraction_towercomment to get the length at that height. The wiki warns that the; retractlines may not show the full retraction length. - Pick the shortest clean value. The wiki defines the optimum as the shortest length that produces the cleanest tower. Extra millimetres beyond that buy nothing and add jam risk.
- Then tune speed. With distance fixed, Teaching Tech’s calibration generator varies retraction speed in a separate print, then extra restart distance, then Z-hop, one variable per print. It works without OrcaSlicer.
- Save it as a PLA filament override.
If every section strings, the wiki’s advice is to dry the filament and check that the nozzle is installed without leaks. Drop the nozzle 5–10 °C before extending the range past 6 mm. The travel-speed and temperature side of the problem is covered in how to fix stringing on 3D prints.
How much does pressure advance change the number?
A lot, and downward. Marlin’s Linear Advance documentation says retraction distance “may even be as low as 0” once the K-factor is right, because nozzle pressure at the end of a line drops to nearly zero. Klipper’s pressure advance guide suggests a small slicer retract, such as 0.75 mm, may still help.
Bowden machines are where this matters most. Klipper puts typical pressure advance values between 0.050 and 1.000, “the high end usually only with bowden extruders,” and its tuning tower uses FACTOR=.020 for long Bowden setups against .005 for direct drive.
The two firmware docs disagree on wipe. Klipper recommends wipe-on-retract and disabling z-lift. Marlin says to disable wipe while retract and combing, and to turn off slicer pressure features such as coasting and extra restart length because they interfere with Linear Advance. Settle it on the tower: after the pressure advance calibration, rerun the retraction test, once with wipe on and once with it off, and drop the range to 0–3 mm if the first pass landed low.
Which hardware faults look like bad retraction?
Four faults routinely get misread as a retraction problem: a PTFE tube not butted against the nozzle, a coupler that lets the tube shuffle, wet filament, and over-retraction itself. Rule them out before pushing distance past 6 mm, because no retraction value fixes them.
- Tube gap at the nozzle. On hotends where the PTFE runs down to the nozzle, a gap fills with molten PLA that oozes regardless of retraction and eventually jams. Cut the tube end square, reseat it hard against the nozzle and lock the coupler.
- Coupler play. A worn collet lets the tube slide a fraction of a millimetre with every retraction, and that motion is subtracted from the retraction. A collet clip or a new coupler stops it.
- Moisture. Prusa lists wet filament as a cause of heavy stringing and suggests trying another spool. Dry it and reprint the same tower before blaming the brand; if the clean band moves, it was moisture.
- Over-retraction. Pulling too far drags softened filament up into the cooler part of the hotend, where it can solidify and jam. On an all-metal heatbreak fed by a Bowden tube, this is the classic mid-print clog.
How do you verify the setting?
Print two things: a two-tower stringing test and a real part with plenty of travel between islands, at least two hours long. The setting passes when strings are gone, line starts after travel are neither gapped nor blobbed, and the extruder never clicks.
- Strings: none, or wisps that brush off with a fingernail.
- Seam starts: a small gap where a wall resumes after travel means under-priming, so slow the prime or shorten retraction. A zit means the opposite.
- Extruder: no clicking across the long print, and no flattened, chewed sections when you unload the filament afterwards.
- No mid-print jam: clogs from long retractions tend to appear late in a long job, so a tower alone is not proof.
FAQ
what retraction distance should i use on an ender 3 v2 with pla
Use 5 mm at 60 mm/s with 40 mm/s deretraction as the starting point, because that is what OrcaSlicer’s stock Creality machine profile ships and the Ender-3 V2 preset inherits it. Tune from there with a 1–6 mm retraction tower, and expect the result to drop once Linear Advance is calibrated in Marlin.
is 7mm retraction too much for a bowden printer
Usually yes for PLA. Seven millimetres is beyond Cura’s 6.5 mm base default and past the top of OrcaSlicer’s suggested 1–6 mm Bowden tower, so needing it points to a fault elsewhere: a gap where the PTFE meets the nozzle, a loose coupler, wet filament, or a nozzle temperature set too high.
does a capricorn tube reduce retraction distance
Yes, a tighter-bore tube usually lets you retract less, because the filament has less slack to take up before the hotend end moves. Capricorn XS is specified at 1.9 ± 0.05 mm inside diameter against the nominal 2 mm of generic PTFE, but the vendor publishes no retraction figure, so rerun the tower after fitting it.
should i use z hop for pla on a bowden printer
Use Z-hop only if the nozzle is striking the part. Prusa’s knowledge base says a lower Lift Z improves stringing, and Klipper’s pressure advance guide recommends disabling z-lift on retract. If you need it, start at Cura’s Creality value of 0.2 mm rather than OrcaSlicer’s 0.4 mm, and keep combing enabled.
