This slab of concrete is one of the cheapest
and most effective upgrades you can get for
your 3D printer.
Let me tell you why and let’s get more technical
and talk a bit about decoupling and why something
springy is not necessarily a damper.
We’ll take a look at printing noise and
how print quality is affected by different
printer bases.
Guten Tag everybody, I’m Stefan and welcome
to CNC Kitchen.
Raycon with their Everyday E25 wireless earbuds
sponsored part of this video.
Get 15% off your purchase by using the link
in the description!
I print a lot and this also means that many
of my prints run overnight.
Unfortunately, our bedroom is right next to
my office in which my main printers usually
are.
When I got into 3D printing it was a real
pain because the printing noises just kept
me from some good night sleep so I usually
only ran them during the day.
A couple of years ago I started putting cheap
pavers below my machines that you can get
in many different sizes from the hardware
store.
You can see them in plenty of my videos and
viewers keep asking, what they are and why
I use them.
What are your favorite cheap and effective
printer upgrades?
Let us all know in the comments?
So why do I use a heavy piece of concrete
under my printers?
Well, primarily because they reduce the noise
level of the printer significantly.
And the important thing here is that they
don’t only reduce it in the room in which
they are.
Even more important, the setup that I use
makes the printers way less hearable in the
rest of the house.
Printing noise usually has two main sources.
The first one are the stepper motors with
induce higher frequency vibrations.
As their name already suggests, they don’t
turn continuously but in discrete steps.
Most motors have a step angle of 1.8°, which
means 200 steps per revolution.
Stepper motor driver chop those full steps
down to microsteps the make the motion more
smooth, still it will never be 100% smooth
after all.
This stepping and the magneto-mechanical system
that gets excited cause the well-known printing
noise of machines that use, for example the
good old Allegro A4988 drivers.
More recent drivers eliminate that problem
very well, but there are still some vibrations
caused, especially during fast travel moves.
The other, lower frequency vibrations emerge
during direction changes, so accelerations,
that induce forces on the frame and basically
shake it.
Still, most of the sound isn’t actually
directly coming from the motors themselves,
but from other parts of the printer, like
the bed or the frame, that resonate at those
frequencies and emit sound.
You probably all know these small music boxes.
If you hold them in your hand and turn the
crank they play a song but not too loud.
As soon as you put it on a table the sound
gets highly amplified.
And this is also what happens if you have
your printer sitting on a desk.
The printer itself emits noise but the table
on which it’s sitting is basically acting
like a big loudspeaker.
Even worse, the table transmits the vibrations
into the floor and into your house, making
even the floor in your bedroom a speaker.
I put a microphone on the floor of my bedroom
and once ran the printer directly sitting
on the table, and on a paver with foam below
it.
I applied similar amplification on the audio
so that you can hear the difference.
To avoid that from happening, we need to decouple
the vibrating parts from and resonance bodies.
This could already start by using those stepper
motor dampeners that you put between the motor
and the mounting points.
What we usually do is to add a couple of rubber
feet or felt pads under our printer though
there are also other solutions around, like
these 3D printed spring feet, which can be
a good start.
As you’ve seen, I especially like to use
these cheap concrete pavers because not only
do they give me a level surface, they also
enable me to put softer materials like foam
under the machine.
They distribute the load more evenly for even
better decoupling.
You shouldn’t put your machine directly
a soft materials, because not only can they
warp the frame, they also might get ineffective
because they get totally squished.
And a big piece of foam is a potential fire
hazard.
Though also with the paver, make sure that
no wires constantly rub over the rough surface.
To find out how the different decoupling solutions
work, I set up a small test in which I placed
my old Prusa Mk2, that still has a bit louder
stepper drivers, on a table with varying media
of separation and then ran a short test GCode,
while measuring the noise level.
I’ll also talk about changes in printing
quality with these methods at the end of the
video.
I always ran the test 3 times and calculated
the average peak volume.
First, I removed the felt pieces for our baseline.
If we listen to the test pattern, the movements
in the x-direction are pretty quiet, and movements
of the bed, so when the y-axis is involved,
are significantly louder.
The bed acts as a resonator, which is excited
by the stepper motor and probably also the
linear ball bearings.
The maximum sound level is 67.7dB.
Adding the felt pads already reduces the noise
level significantly and we end up at 59.6dB.
The felt pads came delivered with my MK2,
so how can we further improve on the noise.
The next significant reduction is the use
of printed spring feet.
Here we end up with a maximum noise level
of 57.5dB.
I used them years ago, but quickly noticed
that they might not be optimal because of
their springiness, on which I’ll go into
details in a bit.
These pads consisting out of pressed together
rubber pieces are often used under washing
machines for a very similar purpose.
Putting those under the printer directly or
under the concrete paver results in pretty
much the same levels leaving us at around
57dB.
Next comes probably the visually most pleasing
solution, and this is the paver with thick
felt feet.
Here the resulting noise level was 56.5dB.
These blocks made from foam pieces are the
parts that I’ve been using for the last
two years under my main machine but are sometimes
hard to find.
Their noise level was pretty much the same
as the last one with 56.5dB.
I got the best results from this really soft
packing foam where we even got below 56dB
during the travel moves.
And here a comparison between the best, and
the worst.
So the soft materials provide a separation
layer and prevent the vibrations from traveling
from one part to the other.
Different types of materials have specific
properties and use cases.
Rubber is well known for this application
and as a rubber mat can be used even for heavy
parts like your washing machine.
For the lighter 3D printers, this type is
probably a bit too hard and prevents good
decoupling.
Rubber is on the one side springy but also
is dampening, and this is a point I really
want to talk about because spring and damper
are often mixed up.
A spring is a component that can store potential
energy due to its elasticity and release it
again.
An ideal spring leaves the energy in the system
but can cause catastrophic resonances.
A damper, on the other hand, is a device that
usually absorbs kinetic energy, so movement,
and converts it into heat and radiates it
away, so it takes energy out of the system.
In reality, there is no pure spring and no
pure damper; it’s always a combination of
both, and the ratio of spring stiffness and
damping ratio is essential for a dynamic system.
This is a quite a technical and complex topic
and in our case, it’s probably sufficient
to use trial-and-error.
Still, for our application, this means that
we, on the one hand need the spring part for
the vibration isolation and on the other hand,
if we don’t add an additional damper, the
springs can cause the whole printer to wobble
around and resonate, potentially causing problems.
For this reason, the spring feet, even though
they work, are maybe not the best idea to
use under a printer because they only damp
very little.
People have been tackling that problem by
using squash balls between the printer and
the table with great success, because they
merge springiness with dampening.
I tried to illustrate that with a small test
by dropping different types of balls and recorded
how high they bounced back.
A hop ball is the worst in terms of damping
and bounces almost all the way back, but that’s
also by design.
The golf ball lost 24% in height.
The squash ball almost didn’t bounce back
and lost 84% in height.
At last, I also found a juggling ball that
basically didn’t bounce back at all.
It’s filled with beans, and the friction
between the particles absorb most of the potential
energy.
So might this even be a better solution than
a squash ball?
Probably no, because, as I said before, we
need both the elastic behavior and the dampening
component, and the bean bag misses the springy
part.
The squash ball seems to be a good compromise
between both with some springiness but also
lots of damping.
Rubber has dampening properties due to the
internal movement of the polymer chains.
Foam, on the other hand, has also “some”
of this property but also dissipates the energy
because when it’s squised, the air inside
travels through the pores and causes viscous
damping.
Due to the internal structure, so type of
base polymer, open or closed porosity and
so on, the amount of dampening can differ.
Again I set up a small test where I dropped
the golf ball on different materials and recorded
the energy loss after the first bounce.
The reference again lost only around 20% of
energy.
The harder and quite dense foam absorbed around
50% of energy.
The rubber pad reduced the bouncing height
by 64% and the soft foam sponge almost 77%.
So how do all of these results correlate with
our noise isolation test?
Actually pretty well, because also here the
soft, open cell foam performed the best though
also the other solutions were not that much
worse.
What I want to say with that is, that putting
anything soft under your printer is usually
beneficial because the elastic behavior decouples
it from the table.
Some damping might additionally be useful
to prevent the printer from resonating.
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Another interesting point I noticed in the
past is, that adding some flexibility under
the printer, can even improve your printing
quality.
For this reason, I chose four different printing
bases and printed a 3DBenchy and also my ringing
test on each using the same GCode.
I placed the printer directly on the table
with only the felt pads.
I used the spring feet.
I placed it on the concrete paver with only
felt feet below and finally the paver on some
foam.
The difference on the Prusa was not huge,
but you can see that there are fewer ringing
marks on the parts that were on a flexible
base.
The part that were printed on a rigid surface
showed a little more.
In the past I have seen this even more exaggerated
to my CoreXY Sapphire Pro for example, where
the moving print head sits on the top and
has quite some leverage for causing vibrations.
The explanation that I have for the improvement
in quality is, that if you have a flexible
base, the forces that are generated during
the directional changes don’t cause the
frame and other motion components to deform
but will cause the printer to move as a whole
unit and therefore deform less.
The concrete paver here again has advantages
because it moves as a unit keeping the base
of the printer on one plane.
If you have flexible components under each
foot, your frame might warp.
Maybe you have different thoughts on this
topic.
If so, then let me know down in the comments!
In summary, putting a $2 slab of concrete
under your printers with some soft padding,
even only the packing foam that your printer
came with, is, in my opinion, one of the most
simple and best upgrades that you can make.
Not only have we seen that we can reduce the
noise in the room the printer is, but we also
prevent our house from becoming a big speaker.
Besides that, I have found that adding some
flexibility to your base can also improve
your print quality by reducing ringing marks.
Well, and if you came to the point that your
printer doesn’t get any quieter, give yourself
a break and try out Raycons latest earbuds,
the E25.
They got a great noise-isolating fit and sound
just as good as other premium wireless earbuds
but only cost half as much, and with the special
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I got mine a couple of weeks ago and have
been continuously using them ever since.
They come with a ton of different silicone
tips to fit basically every ear out there.
They are nice and comfortable to wear but
hold securely in place, even when I constantly
run up and down the stairs to check on prints
in my basement.
Pairing is super simple and reliable.
They last for 6 hours of playback time and
a total of 24 hours with the charging case.
Raycons Everyday E25 earbuds are small and
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I, sometimes only wear one if I still think
I should be able to communicate with the outside
world.
With my old pair, this wasn’t possible,
because the connecting cable just always pulled
them out of my ear.
Not with the Raycon and I’m still able to
answer calls, really awesome.
If you also want to get a pair yourself, check
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your order.
Thank you, Raycon, for sponsoring part of
this video!
Thanks for watching everyone, I hope you’re
all doing well!
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Go check out my other videos if you currently
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Stay healthy, auf wiedersehen and I hope to
see you in the next one!
