Shortly after assembling my new Shapeoko 3, I realized that the milling
process was quite loud, and would likely disturb my neighbors. (I live in a small
apartment.) Wanting to avoid that, I decided to build a “soundproof” enclosure
for the Shapeoko.
Here I’ll document my design for the enclosure, as well as some of the thought
that went into it. I hope this effort benefits others who are looking to build
I assumed that others had already encountered and solved this problem, so I
began by researching what they had done. Generally
speaking, most of the designs I encountered seemed to be variations on this
Build a five-sided box (ie, a cube without a front face) out of a heavy
Complete the box with a transparent front face - typically made out of
Optionally line the cube’s interior with sound-deadening material like
Many of the enclosures seemed sensible, but I was uncertain how effective they
were at deadening sound. It seemed as though many people were building
enclosures simply for the sake of dust-containment, whereas my primary goal was
sound-isolation. Thus, I decided to take a slightly different approach.
My primary fear with the designs I researched was that the thin, acrylic front
panel would “leak” too much sound. To minimize sound leakage as much as
possible, I wanted to build the entire enclosure out of a heavy material -
including the front panel.
The obvious drawback to that approach, of course, is that it would prevent me
from being able to see inside the enclosure.
To mitigate that problem, I decided to shamelessly steal the solution
implemented by the Glowforge: embed a webcam (and lighting) inside the
With a general plan in mind, I was nearly ready to begin modelling the
enclosure in Sketchup - my preferred CAD program for simple projects like
this. (It’s really easy to use.) Before I began, though, I wanted to educate
myself more on the topic of sound-isolation, which I knew little about.
Sound-isolation is a complicated subject, but from my research, I gathered a
few key points:
The enclosure must be “airtight”.
The thicker and heavier its walls, the better.
The more compact it was, the better. (Cavernous spaces resonate more.)
Lining the enclosure’s interior with acoustic foam would help to mute
With those design criteria in mind, I modelled the enclosure in Sketchup:
I also laid out a cut pattern for the panels:
The Sketchup file is available for download here. Note that I
did not bother to model every detail, like where the feet, hinges, and latches
were to be installed. Those details are relatively unimportant, though, and can
easily be inferred from the upcoming photographs.
With a Sketchup model worked out, I was ready to begin the physical build.
I chose to build the box entirely out of 3/4” MDF, because:
I’ve worked with it in the past and understand its properties
It’s a good source of “cheap mass”, making it suited for soundproofing
I started by cutting the MDF panels to size per the Sketchup model, and then
assembled four sides of a cube:
I glued the panels together using Elmer’s wood glue. I’m generally not a fan of
glues because they make “disassembly” into a destructive process, but in this
case, I used glue because it was the easiest solution. Had I more workspace,
more patience, and larger clamps, I would otherwise have preferred to use
After the glue dried, I caulked the glued seams inside and out in order to help
make the box “airtight”. (I put “airtight” in quotes because, of course, the
box is not literally airtight.)
Once the caulk dried, I installed some threaded leveling-guides near each
corner of the enclosure’s bottom face:
With the leveling-guides in place, I then applied speaker-box gasket-tape to
the panel edges. This would help to keep the enclosure airtight when assembled:
(Ignore the orange straps in these photos - they aren’t a permanent part of the
design. I just used them to apply clamping pressure while the glue and caulk
With the gaskets in place, I then attached the front panel to the enclosure
using a continuous hinge:
Then I installed a pair of latches that would allow the front panel to be
sealed tightly against the gaskets:
I then used a heavy-duty stapler to attach acoustic foam tiles to the
enclosure’s interior walls:
I then mounted a pair of battery-powered LED light-strips to the inside surface
of the front panel. The LEDs could be rotated in their housing, so I rotated
them downward toward the spoilboard:
I then used a magnetic mount to mount a small webcam between the light-strips,
and likewise aimed it down at the spoilboard:
This shows the completed interior surface of the front panel:
I then placed the entire enclosure atop four short cinder blocks, and leveled
it using the leveling-guides. (Of course, it would have been better to seat
this on a slab, but I live in a second-story apartment.)
Lastly, I rigged up a some electrical controls on the enclosure’s exterior. The
power-strip provides me with an “emergency” switch that I can use to cut power
to everything if something goes wrong. The individual switch (that juts out of
the power-strip) powers the router, allowing me to turn it on and off while the
enclosure is closed. (I consider this a safety feature.)
The enclosure, so far, appears to have been very successful. It
dramatically lessens the noise emitted while milling.
My one regret regarding this project is that I did not quantify the
before/after sound emitted in decibels. Subjectively, however, I’ll say that it
cuts the noise down from “very loud” to “barely audible”. Again, subjectively,
the noise emitted by the enclosure while cutting is now perhaps only twice as
loud as a typical PC fan.
So, I happily consider this project a success. I don’t have comments on this
blog, but if you’d like to comment or ask me a question, feel free to tweet to
me at @chrisallenlane.