Extrusion width determines how wide the line
of material is that your 3D printer extrudes through it’s nozzle and that’s a parameter
that I rarely touched until now. For todays video, I’ve investigated the
interesting influence of this setting on print quality and layer adhesion and oh boy, if
you want to have a strong print fast then this might be interesting for you! Guten Tag everybody, I’m Stefan and welcome
to CNC Kitchen. This video is sponsored by Squarespace. Squarespace is an all-in-one platform that
I recently started using to easily provide write-ups and the results of my research. Create your own website by browsing squarespace.com/cnckitchen. More on Squarespace at the end of this video! Most of us probably change the layer height
we print with quite a bit and adjust it depending on if we want something fast or nice. A parameter that I don’t see many adjust
is the extrusion width the slicer uses. And at this point I’d be really interested
if you ever touched it and why. Let me know in the comments! The extrusion width is how wide the line of
material that is printed is. Please don’t mix that up with the extrusion
multiplier! The extrusion multiplier only adjusts the
flow of material but keeps the distance between tracks the same, extrusion width sets the
distance between extruded lines and adjusts material flow accordingly. Most of us probably use a 0.4mm nozzle on
our machines and the width of the filament line doesn’t necessarily need to be exactly
that value. Going smaller might seem a bit counterintuitive
but is actually possible and can even be beneficial for quality. Most slicers use a standard value of 100 to
120% of the nozzle diameter. This means the material extrusion is as wide
as nozzle orifice or just a bit wider. Since the nozzle tips have a bit of flat area
around the hole the layer height will be kept and the material will not be squeezed upwards. Also, if I later talk about extrusion width,
I will usually use the percent value which means what percentage of my 0.4mm nozzle diameter. Some slicers like Cura hide extrusion width
by default and let you define the wall thickness which doesn’t necessarily need to be a multiple
of the extrusion width. For full control over that value I used PrusaSlicer
2.1 for all prints. With higher extrusion widths the pressure
inside of the nozzle needs to be higher as well to squeeze the material to the sides
after it leaves the nozzle. This additional pressure does not only squeeze
the material to the side, it will also press the individual layers together more which
poses the question if that also helps with the layers bond together better? This is exactly the task of todays video. In order to investigate that question I printed
3DBenchys for quality assessment and layer adhesion samples as well as my test hooks
for strength testing. I thought it would be interesting to even
start from extrusion widths smaller than the nozzle bore up to really high values. I printed all parts with a 0.4mm nozzle and
started at 90% extrusion width and went all the way up to 250%. That’s 0.36mm to 1mm and the latter is the
diameter of the nozzle tip of a standard E3D nozzle. Pay attention if you use different nozzles
for example the MK8s of the CR-10 and all its variants and clones because their nozzle
tip looks different which has advantages and disadvantages. The parts were printed on my Original Prusa
i3 MK2S in SpoolWorks PLA at a nozzle temperature of 210°C, 50% fan and 0.16mm thick layers. In order to have ambient temperatures as constant
as possible I had the printer in my basement where I have a quite consistent temperature
of 20°C. Each printjob for one extrusion width consisted of one 3DBenchy and a pair
of 3 layer adhesion specimens. The 3DBenchy and the test samples were printed
sequentially so that the layer times were consistent and didn’t jump. At first, let’s take a look at the print
quality. It was very interesting to see how all 3DBenchys
looked basically the same up to 140% extrusion width. Even the model with 90% width didn’t look
differently. At 160% I was slowly able to spot artefacts
in the overhanging regions probably because the material is squeezed out that much. At 250% the whole surface was even strangely
textured. At 200% and higher the flag pole base just
vanished not because of printing problems but because the part just had too thin walls
to be printed with a 0.8mm extruded line. At higher extrusion widths some areas looked
as if they were a bit underextruded though I think was only the overlapping areas with
the perimeter that needed tuning. All in all, the printable range is way bigger
than I initially thought and 150% width still seems reasonable. You have to keep in mind that especially thin
areas might suffer faster in quality, because the additional extrusion pressure will create
a downward-force on the part, squishing it together. Also, the additional material will add drag
between the nozzle and the part and therefore might deform it due to the shear forces or
cause other issues. Another thing that you have to keep in mind
is that with thicker extrusions you also pump out more material in the same amount of time
that needs sufficient cooling. In the worst case you might even get to the
limit of your hotend where it’s not able anymore to melt the material properly causing
even more issues. In such a case it might be a good idea to
take a look at hotends like E3Ds Volcano or just bump the temperature up a little. Let’s now continue with the layer adhesion
tests. The samples that I printed were measured and
then mounted in my DIY universal test machine where they were are all loaded at a constant
speed until failure. This should give us very comparable values
because it removes the human factor. Here again, the samples up to 140% extrusion
width looked very similar and only at wider extrusions some problems seem to occur. For statistics I tested 3 samples for each
setting and I didn’t test them in order to avoid any systematic error. The results are very interesting because we
can clearly see that the layer adhesion slowly rises from 90% to the maximum probably at
150%. After that it falls again but the reason for
this behavior might also just be that the samples got really rough and the stress risers
on the surface caused premature failure. Just for a reference, the pure material strength
is at around 60MPa so even though the layers seem to adhere better we are still a bit away
from perfect fusing of the layers but again, a bit closer. As I already mentioned in the last video this
is actually a video series where I analyze the influence on strength of different printing
parameters and then ultimately want to combine them to get the maximum strength out of our
3D printed parts. Design of Experiements if you know what I
mean. If you don’t want to miss that, make sure
that you’re subscribed and have also selected the notification bell! At the lower extrusion widths, the crack planes
are only over one or two layers and they become more un-uniformly the more material is squished
out. Another indication that we’re on the right
track. Next, in order to apply that to a real problem
I also printed a couple of my test hooks to see if our findings on the simple layer adhesion
samples also hold true here. All in all I printed 12 parts, all standing. 3 had 2 perimeters and 100% extrusion width. 3 had the same number of perimeters but at
200% width, doubling the wall thickness. 3 were printed with 4 perimeters and 100%
width resulting in the same wall thickness. 3 were right in-between with 3 perimeters
and 133% extrusion width. Of course, the parts with thicker walls will
be stronger, but is it better to use more perimeters or thicker extrusions. By the way, I did a whole video on why you
should make your parts stronger by adjusting perimeters instead of infill ratio. Card up here! Besides strength I also noted down printing
time and weight. I, for my part work in aerospace and am impatient. That means that for once, I want the most
strength per weight and the strongest print in the shortest amount of time. Some might argue that print time doesn’t
play a role for them so by just using more perimeters and infill they make their parts
stronger. But still if you’re someone like this then
having even stronger parts with wider extrusions might be a bonus on top. The quality of the hooks wasn’t as different
as with the 3DBenchies and the layer adhesion coupons. Even the 200% sample still looked okay. Since I only used 20% infill there always
was a bit of space left the push the surplus of material. So as suspected, the hooks with only two perimeters
failed at first at around 20kg of load. Next were the hooks with 4 perimeters and
100% extrusion width at 33kg but with quite some scatter. Second came the parts with 3 perimeters and
133% extrusion width at 37kg of failure load and the strongest ones were actually the ones
with only 2 perimeters and double the normal extrusion width at 39kg on average. This is almost double the strength with the
same printing time when we compare it to the first sample. The printing time was even lower because the
infill is thicker so less lines need to be extruded. So, if you are as impatient as I am, then
thicker extrusions will give you stronger parts in the same amount of time. If you are looking for parts that use the
given material as efficiently as possible, thicker extrusions will help you in this regard
as well because layer bonding will be better. Pretty cool, huh! So, what’s the verdict? We have once again learnt that the strength
of our 3D prints is not only a result of the materials we use but also the settings. Using wider extrusion seems to help layer
adhesion because the material is squished more into the previous layer. At some point you run into quality problems
but to be honest, that’s usually not the biggest concern with mechanical parts. If you need a strong part quickly then upping
the extrusion width is almost directly proportional to the gain in strength, which is really cool! You might have the same advantage with a bigger
nozzle, but this method saves you the hassle to switch all of the time. Just keep in mind that you will extrude more
amount of material in the same timeframe so make sure your hotend and cooling setup is
able to handle that. The detailed test results are available for
my Patron supporters but if you only want to take a second look at the graphs than make
sure to check out my new website where I’ll be posting write-ups of all of my videos. This is thanks to todays videos sponsor Squarespace. Squarespace is a is THE all-in-one platform
to build a beautifully looking online presence. Not only do they have a ton of professional
templates for you to start with and free stock photos for quick customization their online
editor is so intuitive to use and helps me create and maintain my website with no hassle
at all. If you also have a business or just want to
share your latest hacks and prints or even create a shop in a professional manner than
start your free Squarespace trial today at squarespace.com/cnckitchen and use code CNCKITCHEN
to get 10% off your first purchase. If you’re ever stuck and need assistance,
they have a great help center and 24/7 customer support. Try out Squarespace 2 weeks for free by browsing
squarespace.com/cnckitchen and let them know who send you by using code CNCKITCHEN for
10% off upon checkout. Thank you Squarespace for supporting this
channel! Thank you for watching! I hope you learnt something new today. If you did, then please leave a like and make
sure that you’re subscribed for future investigations. If you want to support my videos and research
than consider becoming a Patron or help me out in other ways. Also check the rest of my video library, because
I’m just about to reach 100 videos and there is a ton more for you to watch and enjoy. I hope to see you in the next one, auf wiedersehen
and goodbye!
I have always read people touting the merits of a wider extrusion width or larger nozzle diameter and the strength of adhesion between layers.
Is it possible that a hybrid mode could be made and utilized where the interior of the print could benefit from greater strength and reduced print time of a wider extrusion width, and the external shells from the surface quality of normal extrusion width?
I know there is time and development into concepts like this, but I would like to see more optimizations like this that save print time while simultaneously increasing the mechanical properties of prints! Win Win for the user!
Another concept I have seen is to print perimeters at “half height” for resolution, and the infill at full or double the height of the perimeters.
The perimeters would be printed at a multiple of infill height, say 3 layers at 0.1mm deep, then the machine would proceed to the infill with 1 layer at 0.3mm with no clearance issues during extrusion.