<p>Retraction is the reversal of the direction of the filament and is generally used when moving from one non-contiguous point of the print to another, in order to prevent <em>stringing</em> and <em>oozing</em> of the filament. If retraction is not employed then the filament still coming out of the nozzle, after the last point was printed (and paused), will stretch, thus creating a fine string, as the print head is moved to the next position where printing is to recommence.</p>
<p><a href="https://i.sstatic.net/hpa5g.jpg" rel="nofollow noreferrer" title="Stringing"><img src="https://i.sstatic.net/hpa5g.jpg" alt="Stringing" title="Stringing" /></a></p>
<p>The <strong>retraction speed</strong> is the speed at which the filament is retracted, or pulled back (by the extruder stepper), and the <strong>retraction length</strong> is the amount that is pulled back.</p>
<p>These settings are dealt with in the <a href="https://www.hornbach.de/data/shop/D04/001/780/491/279/983/6541035_Doc_02_DE_20171205104244.pdf" rel="nofollow noreferrer">XYZware User manual</a>, on page 43, section <strong>11.5 Retraction</strong></p>
<blockquote>
<p><strong>11.5 Retraction</strong></p>
<p><a href="https://i.sstatic.net/NCuh2.png" rel="nofollow noreferrer" title="Retraction dialog"><img src="https://i.sstatic.net/NCuh2.png" alt="Retraction dialog" title="Retraction dialog" /></a></p>
<p><strong>11.5.1 Retract Length</strong></p>
<p>In printing object, before large movement of print module, print
filament will be drawn back, such that slight negative  pressure
occurs  in  print  nozzle,  preventing  material  from  adhering  to
the  object  while  moving, improving surface quality of print object</p>
<p><strong>11.5.2 Activate Threshold</strong></p>
<p>Such  setting  will  allow  users  to  set  up  retraction  mechanism
activation  style.  For  setup  mode,  users  usually specify the
minimal print module movement distance for retraction mechanism
activation</p>
<p><strong>11.5.3 Lifting height for extruder withdrawal</strong></p>
<p>After retraction, the print module will be elevated slightly with such
setup value. Such action prevents material from adhering to the
object, and makes a more orderly final print stop point. However, it
should be noted that excessively large elevation will extend print
preparation time for the next print layer, and portions of angles may
results cooling and difficult to bond conditions between layers</p>
<p><strong>11.5.4 Add Extra Filament after Travel &lt; Retraction</strong></p>
<p>Material  compensation  may  be  used  to  improve  upon  holes  or
poor  extrusion  due  to  excessive  extruder withdrawal</p>
</blockquote>
<p>Retraction speed isn't dealt with in the above section though. In section 3.3, of the <a href="http://wiki.xyzprinting.com/wordpress/xyzware-pro-user-manual/" rel="nofollow noreferrer">XYZware Pro. User Manual</a>, it is mentioned:</p>
<blockquote>
<p><strong>Retract Speed</strong></p>
<p>The speed for pulling filament backwards. Refer to the function introduction in the next chapter for more about retraction.</p>
<p><strong>Hint</strong>:</p>
<p>Cooperation of retraction speed and other print speeds will affect feeding stability directly in printing. A print speed slightly faster than the retraction speed would prevent material squeeze from interrupt.</p>
</blockquote>
<p>However, the manual doesn't then go on to give any setting. However, the default settings should suffice, unless you are experiencing issues with stringing and/or oozing.</p>
<p>A further explanation can be found here, <a href="http://www.flashforge.com/support/stringing-or-oozing/" rel="nofollow noreferrer">Stringing and oozing</a>:</p>
<blockquote>
<p><strong>Reason 2: Retraction Length</strong></p>
<p>The retraction function includes two setting options. One is
retraction length and the other is retraction speed. The retraction
length determines how much melted filament will be pulled out of the
nozzle. In general, the more plastic that is retracted from the
nozzle, the less likely the nozzle is to ooze while moving. As for the
issue, the default setting in the expert mode is enough for you to
solve the problem. If you encounter stringing with your print job, you
can increase the retraction length slightly to test again to see if
the performance improves.</p>
<p><strong>Reason 3: Retraction Speed</strong></p>
<p>The retraction speed determines how fast the filament is retracted
from the nozzle. If the speed is too low, it will make no difference
to your print job., the melted filament will still drop down through
the nozzle and leave on the model. On the contrary, if the speed is
too fast, the filament will be back to the nozzle and cannot be
extruded out in the next movement of printing. As for the retraction
speed setting, users can reserve the default setting which is perfect
for almost every models.</p>
</blockquote>
<h3>Testing your settings</h3>
<p>As 0scar has reminded me, there are a good number of retraction test prints available (cubes, towers, bridges), which will help you check that your settings are adequate. These prints provide models that have a lot of <em>print breaks</em> (points between which printing is paused and then resumed), which can cause stringing to be exhibited. See <a href="https://www.reprap.org/wiki/Calibration#Oozebane" rel="nofollow noreferrer">RepRap Wiki - Oozebane</a>:</p>
<blockquote>
<p><strong>Oozebane</strong></p>
<p>Objective: stop material oozing out of the nozzle during
'non-printing' moves.</p>
<p>Many extruders will emit (ooze) plastic even when the extruder motor
is not turning. To overcome this your slicing software needs to
'retract' the print medium during head movement when not printing. The
retraction creates negative pressure within the hot end heating
chamber which effectively sucks the print medium back up through the
nozzle, stopping it from oozing.</p>
<p><strong>Calibration Object: <a href="http://www.thingiverse.com/download:17661" rel="nofollow noreferrer">oozebane-test.stl</a></strong></p>
<p>The calibration object prints two towers about 30 mm apart. The head
must move between each of the towers at each layer. If your printer is
not set correctly then you will see many fine filaments (or strings)
between the two towers. You can eliminate these filaments by
eliminating ooze.</p>
<p><strong>Calibration Object 2 (Variable sized towers for testing ooze): <a href="http://www.thingiverse.com/download:20868" rel="nofollow noreferrer">variable_size_ooze_test_nobase.stl</a></strong></p>
<p>This is a simple model to help tune reversal parameters for a stepper
extruder (using much less filament before actually testing the
ooziness). It consists of a number of towers with different
thicknesses, with different spacing between each tower. A well-tuned
bot should be able to produce even the smallest towers.</p>
</blockquote>
<p>A simple google search, <a href="http://www.google.co.th/search?q=Thingiverse%20retraction" rel="nofollow noreferrer">thingiverse retraction</a>, shows up a lot of examples, such as:</p>
<ul>
<li><a href="https://www.thingiverse.com/thing:1815784" rel="nofollow noreferrer">10 Minute Mini Calibration Test for Oozing/Retraction at Different Distances</a></li>
<li><a href="https://www.thingiverse.com/thing:1159886" rel="nofollow noreferrer">4 Cube Retraction Calibration</a></li>
<li><a href="https://www.thingiverse.com/thing:2157858" rel="nofollow noreferrer">Retraction Tower Test</a> or <a href="https://www.thingiverse.com/thing:2867033" rel="nofollow noreferrer">String retraction tower test</a></li>
</ul>
<p><a href="https://cdn.thingiverse.com/renders/15/e9/df/74/a4/979ffe4e9f797626812ab0721b2c80df_preview_featured.jpg" rel="nofollow noreferrer" title="Retraction tower"><img src="https://cdn.thingiverse.com/renders/15/e9/df/74/a4/979ffe4e9f797626812ab0721b2c80df_preview_featured.jpg" alt="Retraction tower" title="Retraction tower" /></a></p>
<p>Check out the following (suspiciously similar) tags<sup>1</sup>, for even more examples:</p>
<ul>
<li><a href="https://www.thingiverse.com/tag:retraction_test" rel="nofollow noreferrer">retraction_test</a></li>
<li><a href="https://www.thingiverse.com/tag:retraction-test" rel="nofollow noreferrer">retraction-test</a></li>
<li><a href="https://www.thingiverse.com/tag:retraction" rel="nofollow noreferrer">retraction</a></li>
</ul>
<hr />
<h3>Additional note for Bowden setups</h3>
<p>As <a href="https://3dprinting.stackexchange.com/users/8884/trish">Trish</a> notes in <a href="https://3dprinting.stackexchange.com/questions/6140/what-is-retract-speed-what-is-retract-length/6141?noredirect=1#comment9754_6141">the comments</a>:</p>
<blockquote>
<p>According to my experience<sup>2</sup> it is generally a good idea to add 2 to 4 mm of retraction to a bowden setup in comparison to a direct drive when dialing in the perfect retraction. This is, because some distance is &quot;eaten&quot; by the flex of the Bowden tube.</p>
</blockquote>
<hr />
<p><sup>1</sup> It seems as if Thingiverse could benefit from tag synonyms</p>
<p><sup>2</sup> and <a href="https://toms3d.org/" rel="nofollow noreferrer">Thomas Sanladerer's</a> advice during a stream</p>

CC BY-SA 4.0
2018-06-10T09:18:21.140Z
You may consider adding (to complete the answer) a hint to printing retraction calibration tower that are readily available, e.g. from Thingiverse.
0scar
CC BY-SA 4.0
2018-06-10T09:38:38.847Z
@0scar - Ah, very good point. I'd forgotten about that. Will do so now. Cheers! :-)
Greenonline
CC BY-SA 4.0
2018-06-09T22:54:30.233Z
2018-07-18T12:53:40.377Z
2020-06-18T08:29:41.667Z
Greenonline
<p>On a 3D XYZ printer extruder, I found two terms I have no idea about:   </p>

<ul>
<li>retract speed</li>
<li>retract length</li>
</ul>

<p>What are these and why/how should they be set?</p>

CC BY-SA 4.0
2018-06-09T22:43:10.033Z
Hi KD and welcome to SE.3D Printing..! Do you mean do these terms mean, or what are the actual settings required?
Greenonline
CC BY-SA 4.0
2018-07-18T07:47:14.443Z
Hi KD, did my answer help you at all? If so, please mark your question as answered, by clicking on the accept answer icon (green tick). Doing that will also remove your question from the unanswered list. If your question is still uinanswered, then maybe you could refine your question a little, in order to get a better answer. Thanks
Greenonline
<print-quality><retraction>
What is retract speed & length?
K D
# What is retract speed & length?

(Asked by: username_0 on 2018-06-09)

On a 3D XYZ printer extruder, I found two terms I have no idea about:

* retract speed
* retract length

What are these and why/how should they be set?

**Tags:** print-quality, retraction

> **Comments:**
> **username_1**: Hi KD and welcome to SE.3D Printing..! Do you mean do these terms mean, or what are the actual settings required?  
> **username_1**: Hi KD, did my answer help you at all? If so, please mark your question as answered, by clicking on the accept answer icon (green tick). Doing that will also remove your question from the unanswered list. If your question is still uinanswered, then maybe you could refine your question a little, in order to get a better answer. Thanks  

---

## 1 answers

### Answer by username_1 on 2018-06-09. Score: 9

Retraction is the reversal of the direction of the filament and is generally used when moving from one non-contiguous point of the print to another, in order to prevent *stringing* and *oozing* of the filament. If retraction is not employed then the filament still coming out of the nozzle, after the last point was printed (and paused), will stretch, thus creating a fine string, as the print head is moved to the next position where printing is to recommence.

[![Stringing](https://i.sstatic.net/hpa5g.jpg "Stringing")](https://i.sstatic.net/hpa5g.jpg "Stringing")

The **retraction speed** is the speed at which the filament is retracted, or pulled back (by the extruder stepper), and the **retraction length** is the amount that is pulled back.

These settings are dealt with in the [XYZware User manual](https://www.hornbach.de/data/shop/D04/001/780/491/279/983/6541035_Doc_02_DE_20171205104244.pdf), on page 43, section **11.5 Retraction**

> **11.5 Retraction**
>
> [![Retraction dialog](https://i.sstatic.net/NCuh2.png "Retraction dialog")](https://i.sstatic.net/NCuh2.png "Retraction dialog")
>
> **11.5.1 Retract Length**
>
> In printing object, before large movement of print module, print
> filament will be drawn back, such that slight negative pressure
> occurs in print nozzle, preventing material from adhering to
> the object while moving, improving surface quality of print object
>
> **11.5.2 Activate Threshold**
>
> Such setting will allow users to set up retraction mechanism
> activation style. For setup mode, users usually specify the
> minimal print module movement distance for retraction mechanism
> activation
>
> **11.5.3 Lifting height for extruder withdrawal**
>
> After retraction, the print module will be elevated slightly with such
> setup value. Such action prevents material from adhering to the
> object, and makes a more orderly final print stop point. However, it
> should be noted that excessively large elevation will extend print
> preparation time for the next print layer, and portions of angles may
> results cooling and difficult to bond conditions between layers
>
> **11.5.4 Add Extra Filament after Travel < Retraction**
>
> Material compensation may be used to improve upon holes or
> poor extrusion due to excessive extruder withdrawal

Retraction speed isn't dealt with in the above section though. In section 3.3, of the [XYZware Pro. User Manual](http://wiki.xyzprinting.com/wordpress/xyzware-pro-user-manual/), it is mentioned:

> **Retract Speed**
>
> The speed for pulling filament backwards. Refer to the function introduction in the next chapter for more about retraction.
>
> **Hint**:
>
> Cooperation of retraction speed and other print speeds will affect feeding stability directly in printing. A print speed slightly faster than the retraction speed would prevent material squeeze from interrupt.

However, the manual doesn't then go on to give any setting. However, the default settings should suffice, unless you are experiencing issues with stringing and/or oozing.

A further explanation can be found here, [Stringing and oozing](http://www.flashforge.com/support/stringing-or-oozing/):

> **Reason 2: Retraction Length**
>
> The retraction function includes two setting options. One is
> retraction length and the other is retraction speed. The retraction
> length determines how much melted filament will be pulled out of the
> nozzle. In general, the more plastic that is retracted from the
> nozzle, the less likely the nozzle is to ooze while moving. As for the
> issue, the default setting in the expert mode is enough for you to
> solve the problem. If you encounter stringing with your print job, you
> can increase the retraction length slightly to test again to see if
> the performance improves.
>
> **Reason 3: Retraction Speed**
>
> The retraction speed determines how fast the filament is retracted
> from the nozzle. If the speed is too low, it will make no difference
> to your print job., the melted filament will still drop down through
> the nozzle and leave on the model. On the contrary, if the speed is
> too fast, the filament will be back to the nozzle and cannot be
> extruded out in the next movement of printing. As for the retraction
> speed setting, users can reserve the default setting which is perfect
> for almost every models.

### Testing your settings

As username_2 has reminded me, there are a good number of retraction test prints available (cubes, towers, bridges), which will help you check that your settings are adequate. These prints provide models that have a lot of *print breaks* (points between which printing is paused and then resumed), which can cause stringing to be exhibited. See [RepRap Wiki - Oozebane](https://www.reprap.org/wiki/Calibration#Oozebane):

> **Oozebane**
>
> Objective: stop material oozing out of the nozzle during
> 'non-printing' moves.
>
> Many extruders will emit (ooze) plastic even when the extruder motor
> is not turning. To overcome this your slicing software needs to
> 'retract' the print medium during head movement when not printing. The
> retraction creates negative pressure within the hot end heating
> chamber which effectively sucks the print medium back up through the
> nozzle, stopping it from oozing.
>
> **Calibration Object: [oozebane-test.stl](http://www.thingiverse.com/download:17661)**
>
> The calibration object prints two towers about 30 mm apart. The head
> must move between each of the towers at each layer. If your printer is
> not set correctly then you will see many fine filaments (or strings)
> between the two towers. You can eliminate these filaments by
> eliminating ooze.
>
> **Calibration Object 2 (Variable sized towers for testing ooze): [variable\_size\_ooze\_test\_nobase.stl](http://www.thingiverse.com/download:20868)**
>
> This is a simple model to help tune reversal parameters for a stepper
> extruder (using much less filament before actually testing the
> ooziness). It consists of a number of towers with different
> thicknesses, with different spacing between each tower. A well-tuned
> bot should be able to produce even the smallest towers.

A simple google search, [thingiverse retraction](http://www.google.co.th/search?q=Thingiverse%20retraction), shows up a lot of examples, such as:

* [10 Minute Mini Calibration Test for Oozing/Retraction at Different Distances](https://www.thingiverse.com/thing:1815784)
* [4 Cube Retraction Calibration](https://www.thingiverse.com/thing:1159886)
* [Retraction Tower Test](https://www.thingiverse.com/thing:2157858) or [String retraction tower test](https://www.thingiverse.com/thing:2867033)

[![Retraction tower](https://cdn.thingiverse.com/renders/15/e9/df/74/a4/979ffe4e9f797626812ab0721b2c80df_preview_featured.jpg "Retraction tower")](https://cdn.thingiverse.com/renders/15/e9/df/74/a4/979ffe4e9f797626812ab0721b2c80df_preview_featured.jpg "Retraction tower")

Check out the following (suspiciously similar) tags1, for even more examples:

* [retraction\_test](https://www.thingiverse.com/tag:retraction_test)
* [retraction-test](https://www.thingiverse.com/tag:retraction-test)
* [retraction](https://www.thingiverse.com/tag:retraction)

---

### Additional note for Bowden setups

As [Trish](https://3dprinting.stackexchange.com/users/8884/trish) notes in [the comments](https://3dprinting.stackexchange.com/questions/6140/what-is-retract-speed-what-is-retract-length/6141?noredirect=1#comment9754_6141):

> According to my experience2 it is generally a good idea to add 2 to 4 mm of retraction to a bowden setup in comparison to a direct drive when dialing in the perfect retraction. This is, because some distance is "eaten" by the flex of the Bowden tube.

---

1 It seems as if Thingiverse could benefit from tag synonyms

2 and [Thomas Sanladerer's](https://toms3d.org/) advice during a stream

> **Comments:**
> **username_2**: You may consider adding (to complete the answer) a hint to printing retraction calibration tower that are readily available, e.g. from Thingiverse.  
> **username_1**: @username_2 - Ah, very good point. I'd forgotten about that. Will do so now. Cheers! :-)  

---

