All-metal hotend retraction settings

Set 0.5 to 1 mm of retraction at 30 to 35 mm/s on a direct-drive printer and 2 to 3.5 mm at 35 mm/s on a Bowden printer, then tune with a retraction tower. That is well under the 4 to 6.5 mm in stock profiles for a plastic-lined Bowden hotend such as the Creality Ender 3’s. E3D warns that retractions of 5 mm or more “pull hot filament up into the cold areas of the hotend where they can freeze, adhere and jam.”

What retraction settings should you use with an all-metal hotend?

For an all-metal hotend, start at 0.5 to 1 mm of retraction on a direct-drive extruder and 2 to 3.5 mm on a Bowden setup, at 30 to 35 mm/s. E3D, Micro Swiss and Slice Engineering publish figures in or near those ranges, and Prusa Research and Bambu Lab ship 0.7 to 0.8 mm in their slicer profiles.

Why an all-metal hotend needs less retraction

A PTFE-lined hotend runs a slippery PTFE (polytetrafluoroethylene) liner down into the hot zone. In an all-metal hotend, the filament touches bare metal through the heat break, as the hotend guide for engineering filaments explains. Slice Engineering says aggressive retraction can pull filament “too far into the transitional, cooler areas of the hotend,” where heat creep softens the plastic early. That raises the risk of clogs.

Maker-published starting values

E3D’s figures come from its former V6 wiki, archived in 2023. Its current V6 support page lists misconfigured retraction as a common issue but gives no number, and its Revo support pages publish none.

Slicer defaults on printers with all-metal hotends

Bambu Lab lists the hotend on the Bambu Lab A1 and P1S as all-metal. Prusa Research says the Nextruder on its MK4-generation printers has an all-metal filament path with “no PTFE tubes anywhere.” Their stock profiles, sorted by distance:

Prusa’s knowledge base caps retraction on the Original Prusa i3 MK3S and MK3S+ at 2 mm. PrusaSlicer’s Creality bundle keeps a separate Bowden all-metal hotend template at 3 mm, used by the Creality CR-5 Pro H, against 5 mm for a standard Bowden printer.

How much retraction does an all-metal hotend need on a Bowden printer?

An all-metal hotend on a Bowden printer typically needs 2 to 3.5 mm of retraction, against 4 to 6.5 mm in stock PTFE-lined Bowden profiles. Micro Swiss sets 3.5 mm at 35 mm/s with a 4 mm maximum, E3D suggests starting near 2 mm, and Slice Engineering advises halving your previous setting as a starting point.

Halving gives about 3.3 mm from Cura’s 6.5 mm default, or 2.5 mm from PrusaSlicer’s 5 mm Ender 3 profile. The tube decides where in that range you land. Slice says “the length of the Bowden tube heavily influences necessary retraction lengths,” and E3D adds that slack in the tube couplings has to be taken up by extra retraction.

• Capricorn or other tight-bore tubing. E3D’s Capricorn tube has a 1.9 mm bore against 2 mm for standard tube, so the filament has less room to flex. E3D says that gives “reduced oozing during travel, all achieved with lower retraction distances.” PrusaSlicer’s Creality profiles use 4 mm instead of 5 mm on printers they class as Capricorn-equipped (Creality Ender-5 Pro and CR-20 Pro).
• Locked couplings. E3D says to push the tube fully in while pulling up on the collet, at both ends, so it cannot move during retraction. Its collet clips hold that preload.
• Tube length. PrusaSlicer’s Creality profiles use 6 mm for long-tube printers such as the Creality Ender-3 Max, against 4 mm for short ones.

Ender 3 all-metal hotend retraction settings

On a stock Bowden Creality Ender 3, Ender 3 Pro or Ender 3 V2, drop retraction from the stock profile’s 4 to 6.5 mm to about 3.5 mm at 35 mm/s after an all-metal swap. Keep it at 4 mm or less. Those are Micro Swiss’s figures for its Bowden all-metal setups. Stock slicer profiles for the original PTFE-lined hotend:

Micro Swiss all-metal hotend retraction settings

Micro Swiss’s All Metal Hotend Kit for the Creality CR-10 and Ender 2, 3 and 5 links only an installation video, with no written retraction figure. Its other instructions fill the gap:

• Bowden Dual Gear Extruder for the Ender 3, 5 and 6 and CR-10: about 3.5 mm with an all-metal hotend (4.0 mm maximum) against about 5.0 mm with a stock PTFE-lined hotend. The extruder ships with a Capricorn liner.
• All-metal hotend for the Creality CR-6 SE, a Bowden printer: 3.5 mm at 35 mm/s, 4 mm maximum.
• Temperature: Micro Swiss says the nozzle temperature might need to rise 5 to 10 °C with an all-metal hotend.

After a direct drive conversion

Retraction drops again once the extruder sits on the print head. Micro Swiss gives 1.0 mm for its NG Direct Drive Extruder and at most 1.5 mm at 35 mm/s for its original Direct Drive Extruder. The Ender 3 direct drive guide covers the conversion, and the Ender 3 upgrade comparison shows where a hotend fits among the other upgrades.

How to tune retraction after an all-metal swap

1. Calibrate the rest first. Finish the hotend install, then run temperature, flow and pressure advance calibration. OrcaSlicer’s calibration guide puts retraction after pressure advance and flow ratio, “as both change the pressure in the nozzle.”
2. Enter a starting value. Use the figures above for your extruder type. In PrusaSlicer, retraction sits under Printer Settings > Extruder 1.
3. Print a retraction tower. OrcaSlicer’s built-in retraction test prints a tower whose sections each use a different length. Its defaults of 0 to 2 mm in 0.1 mm steps suit direct drive. For Bowden, the wiki suggests 1 to 6 mm in 0.2 mm steps; an end value of 4 mm stays within Micro Swiss’s maximum. In Cura, the Calibration Shapes plugin by 5axes adds a Retract Tower that steps 0.25 to 1 mm for direct drive and 1 to 5 mm for Bowden.
4. Pick the shortest clean section. OrcaSlicer says “the optimal retraction length is the shortest one that produces the cleanest tower.” Measure that section’s height and find its value from the Calib_Retraction_tower comment in the G-code preview.
5. Change distance before speed. Makers publish distances, and OrcaSlicer’s test varies only length. Hold speed at Micro Swiss’s 35 mm/s, or the 30 to 35 mm/s of the stock direct-drive profiles, while you tune. If strings remain at the shortest clean length, raise speed in small steps. Prusa says a higher speed reduces stringing, but too high “may skip steps in the motor.” The Cura plugin tests speed first, so change one variable at a time.
6. Save it per filament. OrcaSlicer lets you override the printer’s retraction for each filament, since PETG and TPU (flexible thermoplastic polyurethane) may need more than PLA.

Too much or too little retraction: the signs

If a tower still strings at its top, OrcaSlicer suggests drying the filament and checking the nozzle for leaks before adding retraction.

Settings that reduce stringing without more retraction

• Temperature. Prusa suggests lowering the nozzle temperature by 5 to 10 °C to cut stringing. Micro Swiss says an all-metal hotend may need 5 to 10 °C more, or 10 to 15 °C more for PLA in its MK10 kit. Settle it with a temperature tower before you tune retraction.
• Combing and avoid crossing walls. Cura’s Combing Mode keeps travel moves inside printed areas, which Cura says “reduces the need for retractions.” Its Creality base profile retracts only on combing moves longer than 30 mm. PrusaSlicer’s Avoid crossing perimeters (Print Settings > Layers and perimeters > Quality) and OrcaSlicer’s Avoid crossing walls route travel around walls instead of across them.
• Wipe. Prusa recommends leaving Wipe while retracting on, and OrcaSlicer says the wipe “can minimize blobs.” Bambu Studio’s stock profiles wipe 2 mm.
• Minimum travel before retracting. PrusaSlicer’s preset is 1 mm; Prusa notes a higher value saves time but adds stringing. Cura’s Creality base profile uses 1.5 mm.
• Retraction count limit. Cura’s Maximum Retraction Count caps repeat retractions on one stretch of filament, which “can flatten the filament and cause grinding issues.” Its Creality base profile allows 100 within a 10 mm window.
• Long retraction on filament cut. Slice Engineering says to turn off “Long Retraction When Cut” for PLA on its Mako hotend for Bambu Lab printers. The OrcaSlicer wiki says this experimental setting “may also raise the risk of nozzle clogs.”

Retraction for PLA, PETG and TPU in an all-metal hotend