[firmware_retraction]
retract_length: 0.8
retract_speed: 35
unretract_extra_len: 0.0
unretract_speed: 30


That's it. Once this section is in your `printer.cfg`, Klipper responds to `G10` (retract) and `G11` (un-retract) using these parameters.

---

## Full Configuration Reference

### Available Parameters

| Parameter | Default | Range | Description |
|-----------|---------|-------|-------------|
| `retract_length` | 0 | 0–10 mm | Distance filament retracts on G10 |
| `retract_speed` | 20 | 1–200 mm/s | Speed of retraction |
| `unretract_extra_len` | 0 | -5–5 mm | Extra filament pushed on un-retract (compensate for ooze) |
| `unretract_speed` | 20 | 1–200 mm/s | Speed of un-retraction |
| `z_lift` | 0 | 0–10 mm | Z-axis lift height on retract |
| `z_speed` | 5 | 1–100 mm/s | Speed of Z-lift (Voron fast Z available) |

### Full Example with Z-Lift


[firmware_retraction]
retract_length: 0.8
retract_speed: 40
unretract_extra_len: 0.0
unretract_speed: 30
z_lift: 0.3
z_speed: 15


When G10 is called, the printer will:
1. Lift Z by 0.3mm at 15mm/s
2. Retract filament 0.8mm at 40mm/s

On G11:
1. Un-retract 0.8mm at 30mm/s
2. Lower Z back to original position

---

## Slicer Configuration for Firmware Retraction

**The key rule: set slicer retraction to 0 and use firmware retraction.**

### OrcaSlicer / Bambu Studio

1. Go to **Printer Settings > Extruder**
2. Set **Retraction Length** to **0**
3. Set **Retraction Speed** to **0** (or any value — it's ignored)
4. Enable **Use firmware retraction** checkbox
5. (Optional) Enable **Z hop when retract** only if you want slicer Z-hop too

### PrusaSlicer / SuperSlicer

1. Go to **Printer Settings > Extruder 1**
2. Set **Retraction Length** to **0**
3. Set **Lift Z** to **0** (if using firmware Z-lift)
4. Check **Use firmware retraction**
5. In **Print Settings > Extruder 1**, uncheck any retraction settings

### Cura

1. Go to **Extensions > Post Processing > Modify G-Code**
2. Add a script: **Replace** or **Search and Replace**
3. Replace `G1 E... F...` retraction commands with `G10` / `G11`
4. Or better, use a custom start g-code that sets `M207` and disable Cura retraction

---

## G-Code Commands Reference

### G10 — Firmware Retract

Initiates retraction using current firmware settings. No parameters needed (unless overriding):


G10        ; Retract using configured values


### G11 — Firmware Un-Retract

Initiates un-retraction:


G11        ; Un-retract using configured values


### M207 — Set Firmware Retraction Parameters

Dynamically change retraction at runtime (equivalent to `SET_RETRACTION`):


M207 S0.8 R35 F2000 Z0.3    ; Set retract params


Parameters:
- `S` — retract length (mm)
- `R` — retract speed (mm/min, note: mm/min!)
- `F` — un-retract speed (mm/min)
- `Z` — Z-lift height (mm)

**Important:** M207 speeds are in **mm/min**, while config parameters are mm/s. Divide by 60 to convert.

### M208 — Set Firmware Un-Retraction

Sets un-retraction with extra length:


M208 S0.05 F1800             ; Set un-retract extra length and speed


Parameters:
- `S` — extra length on un-retract (mm)
- `F` — un-retract speed (mm/min)

### M200 — Set Filament Diameter

Not retraction-specific, but relevant for proper extrusion math:


M200 D1.75                   ; Set filament diameter


### SET_RETRACTION — Klipper Native Command

Modern alternative to M207/M208, supports more features:


SET_RETRACTION RETRACT_LENGTH=0.8 RETRACT_SPEED=40 UNRETRACT_SPEED=30 Z_LIFT=0.3


### GET_RETRACTION — Query Current Settings


GET_RETRACTION


Returns current firmware retraction parameters.

---

## Firmware vs Slicer Retraction — Detailed Comparison

| Aspect | Slicer Retraction | Firmware Retraction |
|--------|------------------|-------------------|
| Control location | Slicer profile | printer.cfg |
| Change filament? | Edit and re-slice | Change profile at print start |
| Z-hop integration | Slicer must calculate | Firmware handles automatically |
| G-code size | Larger (inline E values) | Smaller (G10/G11 only) |
| Testing | Must re-slice to test | Change at runtime with M207 |
| Multi-extruder | Per-extruder in config | Per-tool in g-code |
| Ooze compensation | Manual in slicer | unretract_extra_len parameter |

**When to use firmware retraction:**

- You have a direct drive extruder (Clockwork, Galileo, Sherpa, Stealthburner, etc.)
- You switch filaments frequently
- You want one slicer profile for all materials
- You use pressure advance (they work well together)

**When slicer retraction might be better:**

- You're troubleshooting a specific g-code path
- You need different retractions within the same print (uncommon)
- You're using an exotic filament that needs very unique retraction behavior

---

## Per-Filament Retraction Profiles

Combine firmware retraction with `save_variables` for instant profile switching:


[firmware_retraction]
retract_length: 0.8
retract_speed: 40
unretract_extra_len: 0.0
unretract_speed: 30

[gcode_macro SET_FILAMENT_RETRACTION]
description: Apply retraction profile for filament type
gcode:
    {% set filament = params.FILAMENT|default("PLA") %}
    {% set fl = printer.save_variables.variables["retract_" ~ filament] | default(0.8) %}
    {% set fs = printer.save_variables.variables["retract_speed_" ~ filament] | default(40) %}
    {% set us = printer.save_variables.variables["unretract_speed_" ~ filament] | default(30) %}
    SET_RETRACTION RETRACT_LENGTH={fl} RETRACT_SPEED={fs} UNRETRACT_SPEED={us}
    M117 Retraction set for {filament}

[gcode_macro SAVE_FILAMENT_RETRACTION]
description: Save current retraction settings for filament type
gcode:
    {% set filament = params.FILAMENT|default("PLA") %}
    {% set fl = params.LENGTH|default(0.8) %}
    {% set fs = params.RETRACT_SPEED|default(40) %}
    {% set us = params.UNRETRACT_SPEED|default(30) %}
    SAVE_VARIABLE VARIABLE=retract_{filament} VALUE={fl}
    SAVE_VARIABLE VARIABLE=retract_speed_{filament} VALUE={fs}
    SAVE_VARIABLE VARIABLE=unretract_speed_{filament} VALUE={us}
    SET_RETRACTION RETRACT_LENGTH={fl} RETRACT_SPEED={fs} UNRETRACT_SPEED={us}
    M117 Retraction saved for {filament}


**Usage:**

SAVE_FILAMENT_RETRACTION FILAMENT=PLA LENGTH=0.6 RETRACT_SPEED=40 UNRETRACT_SPEED=30
SET_FILAMENT_RETRACTION FILAMENT=ABS


---

## Calibrating Firmware Retraction

### The Retraction Tower Method

1. **Slice a 20mm cube** with 5mm height segments, firmware retraction enabled
2. **Add M207/M208 changes** at each segment in the slicer's post-processing
3. **Print and observe** — look for stringing at each segment

**Better approach — Klipper-based calibration:**

Use the `TUNING_TOWER` macro with retraction changes:


[gcode_macro RETRACTION_CALIBRATE]
description: Run a retraction calibration tower
gcode:
    SAVE_GCODE_STATE NAME=retraction_cal_state
    M117 Retraction calibration starting...
    
    {% for i in range(5) %}
        {% set rl = 0.4 + (i * 0.2) %}  # 0.4, 0.6, 0.8, 1.0, 1.2
        SET_RETRACTION RETRACT_LENGTH={rl}
        M117 Segment {i+1}: {rl}mm retract
        G4 P600000  # Wait 10 min (print segment)
    {% endfor %}
    
    RESTORE_GCODE_STATE NAME=retraction_cal_state


### Recommended Starting Values for Voron Extruders

| Extruder | Retract Length (PLA) | Retract Length (ABS) | Retract Speed | Unretract Speed |
|----------|---------------------|---------------------|---------------|-----------------|
| Clockwork 1 | 0.6–0.8 mm | 0.4–0.6 mm | 35–40 mm/s | 25–30 mm/s |
| Clockwork 2 (BMG) | 0.6–0.8 mm | 0.4–0.6 mm | 35–40 mm/s | 25–30 mm/s |
| Galileo / G2SA | 0.4–0.6 mm | 0.3–0.5 mm | 40–50 mm/s | 30–40 mm/s |
| Sherpa Mini | 0.6–0.8 mm | 0.4–0.6 mm | 35–45 mm/s | 25–35 mm/s |
| Orbiter 1.5/2.0 | 0.4–0.6 mm | 0.3–0.5 mm | 40–50 mm/s | 30–40 mm/s |
| Stealthburner CW2 | 0.6–0.8 mm | 0.4–0.6 mm | 35–40 mm/s | 25–30 mm/s |
| Revo CW2 | 0.4–0.6 mm | 0.3–0.5 mm | 40–45 mm/s | 30–35 mm/s |

**Note:** BMG-geared extruders (most Voron extruders) need less retraction than direct-drive because the gear ratio amplifies retraction distance.

---

## Firmware Retraction and Pressure Advance

Firmware retraction and pressure advance (PA) work together but interact:

### How They Interact

1. **PA on retract:** Klipper applies PA in reverse during retraction — it slightly over-retracts to relieve nozzle pressure
2. **PA on un-retract:** PA adds a small extra extrusion at the start of un-retract to re-pressurize the nozzle
3. **Result:** With PA enabled, you may need slightly less firmware retraction length

### Best Practices


# Start with PA calibrated first, then tune retraction
[firmware_retraction]
retract_length: 0.6       # May need 0.1–0.2mm less with PA enabled
retract_speed: 40
unretract_extra_len: 0.0
unretract_speed: 30

[extruder]
pressure_advance: 0.045   # Calibrate this first!


**Calibration order:**
1. Calibrate pressure advance (use the built-in tuning tower)
2. Tune firmware retraction
3. Fine-tune together on a retraction tower

### Warning: Don't Double-Compensate

If you set `unretract_extra_len` to compensate for PA, you'll over-extrude on un-retracts. In general, leave `unretract_extra_len` at 0.0 when using PA.

---

## Advanced Techniques

### Dynamic Retraction Based on Feature Type

Use conditional macros to vary retraction:


[gcode_macro DYNAMIC_RETRACT]
description: Adjust retraction based on travel length
gcode:
    {% set travel = params.TRAVEL|default(10) %}
    {% if travel < 10 %}
        SET_RETRACTION RETRACT_LENGTH=0.0  # Tiny moves, no retract
    {% elif travel < 50 %}
        SET_RETRACTION RETRACT_LENGTH=0.4  # Short moves
    {% else %}
        SET_RETRACTION RETRACT_LENGTH=0.8  # Long moves
    {% endif %}


### Temperature-Compensated Retraction

As nozzle temperature increases, filament oozes more. Compensate:


[gcode_macro TEMP_RETRACT]
description: Adjust retraction based on nozzle temp
gcode:
    {% set temp = printer.extruder.temperature %}
    {% if temp >= 260 %}
        SET_RETRACTION RETRACT_LENGTH=1.0  # High-temp filament
    {% elif temp >= 230 %}
        SET_RETRACTION RETRACT_LENGTH=0.8  # ABS/Nylon range
    {% else %}
        SET_RETRACTION RETRACT_LENGTH=0.6  # PLA range
    {% endif %}


### Z-Lift Only on Certain Moves

Some slicers can't handle fine-grained Z-hop control. Use firmware Z-lift and conditionally enable it:


[gcode_macro ENABLE_Z_LIFT]
description: Enable firmware Z-lift
gcode:
    SET_RETRACTION Z_LIFT=0.3
    M117 Z-lift enabled

[gcode_macro DISABLE_Z_LIFT]
description: Disable firmware Z-lift (for bridging/overhangs)
gcode:
    SET_RETRACTION Z_LIFT=0.0
    M117 Z-lift disabled


---

## Troubleshooting Common Issues

### Strings Between Parts

**Cause:** Retraction too short or speed too slow.

**Fix:**
- Increase `retract_length` by 0.1mm increments
- Increase `retract_speed` to 40–50 mm/s
- Check filament is dry (wet filament strings regardless of retraction)

### Blobs at Layer Start

**Cause:** Too much retraction or un-retract extra length.

**Fix:**
- Decrease `retract_length`
- Set `unretract_extra_len` to 0 or negative
- Ensure pressure advance is calibrated

### Clogged Nozzle / Under-Extrusion

**Cause:** Excessive retraction pulling molten filament into the cold zone.

**Fix:**
- Decrease `retract_length` (common for direct-drive — try 0.3mm!)
- Decrease `retract_speed` (too fast pulls filament up too far)
- Increase nozzle temperature slightly

### Z-Lift Leaving Marks

**Cause:** Z-lift speed too slow, causing ooze on vertical moves.

**Fix:**
- Increase `z_speed` to 15–20 mm/s
- Decrease `z_lift` to 0.2mm or less
- Ensure Z motors can handle the speed (Voron Z is capable)

### G10/G11 Not Working

**Cause:** Slicer not configured for firmware retraction, or missing `[firmware_retraction]` section.

**Fix:**
1. Verify `[firmware_retraction]` is in `printer.cfg`
2. Send `RESTART` to reload config
3. In console, send `GET_RETRACTION` to verify settings
4. Check slicer's "use firmware retraction" checkbox

---

## Complete Setup Example

### printer.cfg Section


[firmware_retraction]
retract_length: 0.8
retract_speed: 40
unretract_extra_len: 0.0
unretract_speed: 30


### Slicer Profile (OrcaSlicer)

- Printer Settings > Extruder:
  - Retraction Length: 0
  - Retraction Speed: 0
  - Use Firmware Retraction: Enabled
- Printer Settings > Basic Info:
  - G-code flavor: Klipper

### PRINT_START Macro Integration


[gcode_macro PRINT_START]
gcode:
    # ... homing, heating ...
    
    # Set retraction based on filament
    {% set ftype = params.FILAMENT_TYPE|default("PLA") %}
    {% if ftype == "ABS" %}
        SET_RETRACTION RETRACT_LENGTH=0.6
    {% elif ftype == "PETG" %}
        SET_RETRACTION RETRACT_LENGTH=0.7
    {% else %}
        SET_RETRACTION RETRACT_LENGTH=0.8
    {% endif %}
    
    # Apply saved PA for this filament
    {% set pa = printer.save_variables.variables["pa_" ~ ftype] | default(0.045) %}
    SET_PRESSURE_ADVANCE ADVANCE={pa}
    
    M117 Starting print with {ftype}
    # ... rest of start gcode ...


---

## Summary

Firmware retraction with `M207`/`M208` (or `SET_RETRACTION`) simplifies your Voron's retraction setup while giving you more control: