Stop the stringing with Retraction! 3D Printing 101 Video Lecture | What is 3D Printing: Basic Knowledge - IT & Software

retraction settings could be one of the
most important factors in getting the
best prints possible off your 3d printer
but it's also one of the more mysterious
settings within your 3d printing slicer
so in this 3d printing 101 we're going
to talk all about retraction I'll
welcome back to 3d printing 101 here on
makers muse so what is retraction anyway
well first let's look at a 3d print with
retraction completely disabled and see
what results we get I put this civil
design together which requires the
printhead to travel between two columns
during the print this will help
demonstrate our issue so this is called
stringing and it's a very undesirable
effect of the extruder using plastic out
as it moves between points of the print
you see as the extruder pushes filament
into the hot end this creates pressure
and this pressure wants to equalize so
simply stopping the extruder won't
actually stop plastic losing out of the
nozzle so this can make a print look
terrible and while tweaking temperatures
can help to some degrees printing with
no retraction will always leave a subpar
result when printing complicated models
ok great Angus but how do we stop
stringing well this is cool retraction
retraction actually pulls filament back
up from the hot end a short amount after
each print move is actually a bit of a
myth around retraction that somehow
creates a suction and sucks molten
plastic back into the hot end that's not
actually the case
all retraction is doing is relieving
that pressure so when you do a travel
move the plastics not going to so easily
lose out so let's turn on basic
retraction settings within simplify 3d
and see what our results are here I'm
telling the printer to move the filament
back 10 millimeters into the hot end at
a speed of around 80 millimeters per
second after each print move let's see
how this turns out clearly there's a
huge improvement straightaway in this
print over the original the stringing is
almost completely gone but it's not
perfect that's still a few tiny wisps on
the model so even with retraction it can
take a short amount of time for the
filament to stop boozing out of a nozzle
that's why we have more advanced
retraction settings you can activate for
example we can coast the extruder which
will turn extrusion off a fraction
before the print move is completed this
helps to relieve the pressure even more
when
as a travel movement helps to eliminate
that little bit of stringing that we had
left behind we can also wipe the
extruder which moves it back into the
print a short amount to help wipe off
any additional using this is the final
result after all of our tweaks using
retraction it's pretty much perfect I
could spend a little bit more time
tweaking my retraction settings further
to get even better results but at the
stage it is now I'm confident to move on
to more complicated prints knowing that
I'm not going to get any stringing
issues it's actually pretty amazing how
much of a difference these settings make
versus our original print with no
retraction settings at all you can have
too much of a good thing however and
this is possible to have too much
retraction too much retraction in your
print becomes evident with little pock
marks of under extrusion at certain
areas of reprint when it moves between a
travel to a print move retraction also
puts a lot of force on your filament as
it sucks it back up and down quickly
into the extruder head and this can
sometimes lead to the extruder gear
chewing filament and leading to jams so
if you're having this issue maybe slow
down your attraction speeds and minimize
the amount of movement it's doing which
will help minimize this filament
grinding and chewing problem it's also
possible you may need to prime your
nozzle when it moves between areas if
you're trying to stop stringing but also
start to print without any under
extrusion issues if you are getting
under extrusion at the start of each
print move this is the setting you want
to try tweaking you're also spending a
lot of time doing these retractions so
obviously print time will increase if
you're using retraction settings but is
it really a big deal if you're getting a
better quality print and as a final pro
tip if you're trying to 3d print with
flexible materials like ninjaflex
then you'd probably want to turn
retraction completely off this is
because as you're trying to 3d print the
flexible materials retraction will tend
to stretch and compress those flexible
filaments and will probably most likely
lead to a jam in your extruder head so
if you are 3d printing with flexible
materials and you do want to manage
stringing issues is actually setting
within simplify through that you can
turn on to try to help this without
using retraction it's called avoid
crossing out lines for travel movements
and means that the string will be mostly
internalized into the print so if you're
printing with flexible materials like a
TPU and for example with my Flex non
extruder I tend to turn this on because
it avoids the stringing being on the
outside of the print
it's obviously not perfect for all
prints but it can certainly save your
bacon if you're trying to 3d print
flexible materials without too
stringing so thanks for watching next
time you're having streaming issues I
hope this video helps you nail down your
attract settings which will help you
turn a good print into a really great
one lets you move to printing very
complicated shapes like this without any
stringing issues at all if you enjoy the
story printing one I want on makers news
guys don't forget to subscribe it helps
me out a huge amount I love bringing
these 3d printing tips tricks and
reviews to you also if you wanna get a
cool t-shirt like this one you can find
a link to it in the video description I
look forward to see you again very
shortly here on makers muse catch you
later
bye