[Music]
if you've watched some of my recent
videos then you've probably seen that i
built a water cooled raspberry pi 4 a
couple of weeks ago
it came out looking better than i
expected and the cooling system
performed really well too
this was obviously a crazy overkill for
a single raspberry pi
but it isn't actually why i bought the
water cooling kit i bought it along with
seven other raspberry pis so that i
could try building my own water cooled
park cluster
while water cooling a single raspberry
pi doesn't make too much sense
water cooling a whole cluster is a bit
more practical the water cooling system
is much quieter than having eight small
fans all screaming in unison
it works really well to keep the past
cool and actually cost a bit less than
some other cooling solutions given that
i'd have to buy eight of them for those
of you who don't know what a park
cluster is
it's essentially a set of two or more
raspberry pi's which are connected
together on a local network
and work together to perform computing
tasks by sharing the load
there's usually one power which is
designated as the host or master node
and is in charge of breaking up the task
into smaller tasks and sending these out
to all the other nodes to work on
the master node then compiles all the
completed tasks back into a final result
to build my cluster i got together 8
raspberry pis a network switch
a usb power supply and then the water
cooling kits cooling blocks and a bunch
of network cables
usb c cables standoffs and screws to put
it all together
i started off by making eight acrylic
brackets to hold the cooling blocks in
position over each part cpu
these are the same design as the ones
used in my previous video but are now
ready to suit the cables and fan
[Music]
do
each bracket consists of two parts which
are glued together to hold the cooling
block in place
[Music]
i also have to include a spacer to lift
the cooling block a bit higher off the
cpu
so that it clears the surrounding
components otherwise i'd have to remove
the display connector from all 8
raspberry pi's
the cooling block mounts onto the part
by securing the power between some red
standoffs which will screw into the base
and some nylon standoffs with a cooling
block to screw into
the bracket picks up on the holes on the
standoffs and clamps the cooling block
down onto the pi cpu
[Music]
i then repeated this seven more times
for the other parts
the traditional way to build a power
cluster is to place standoffs on each
part and then mount them on top of each
other to form a stack
this is the easiest and most compact way
to assemble them but doesn't really work
that well with my cooling block bracket
and isn't all that eye-catching this got
me thinking of a way to better lay out
the cluster so the cooling water circuit
was clearly visible
and the cluster was both functional and
eye-catching
even better would be if it could be
mounted onto a wall i played around with
a couple of layout options
considering the placement of the
components to minimize cable and tube
links
and trying to maintain some symmetry to
keep it looking neat
i settled for having four parts on each
side of the radiator keeping the large
fan as the focal point of the design
i'd be connecting the parts to the
switch using some red patch leads
and i bought a half power usb charging
hub and some short usb c cables to power
the parts
[Music]
once i had my layout in mind i started
marking out my backboard
i positioned all of the major components
onto a piece of mdf
and then marked out where they'd be
placed and the holes needed to mount
them
i checked the clearances required for
the cables and then planned the cooling
water tube layout
it was at this point that i realized
that having four powers arranged in a
square would result in an unnecessarily
complex water cooling loop
so i switched to having the four parts
in a straight line on each side
i also had to make a decision on how
best to run the cooling water loop
if i put each pie in series then the
first will be the coolest in the loop
and each will get progressively warmer
with the last one running the warmest
if i put the pars in parallel then i'll
all receive the same temperature water
but balancing the flow rate becomes a
problem it's quite likely that one or
two each other furthers the wave would
receive little to no flow through them
i decided that warm water was better
than no water and i didn't want about
eight valves to try and balance the flow
rate between them
so i set out connecting them in series
i also had a gap at the top where
there's a lot of free space so i decided
to pull out an old touch panel which i'd
use on a previous project
having a display for the master node
meant that i'd have a way to monitor the
system
and even display stats graphs or
diagnostics directly on the cluster
i finished marking out the layout and
then cut the board to size using a
[Music]
dremel
to mount the raspberry pi's i decided to
design and laser cut a small acrylic
base
this would add a red accent and guide
the power cable through to the back
i also designed a couple of cable and
tube management stands
[Music]
i then marked out the positions for all
the mounting holes and drilled them out
i decided to add some wooden sections to
the back of the board to stiffen it and
to create an area behind the board for
the cable management
and power supply
[Music]
i also made holes underneath the acrylic
bases for the usb cables to run through
[Music]
i then sprayed the front and the back of
the board black
[Music]
i mounted the parts to the network
switch in the cooling water components
[Music]
do
[Music]
the last thing to add was the display
which i mounted onto an acrylic face
panel with some acrylic side supports to
hold it
you'll notice that i had to mount the
master node a bit lower than the others
so that i could get the hdmi cable in
without clashing with the pi next to it
i tied up all of the cables at the back
of the cluster using some cable ties and
cable holders which i cut out of the
acrylic and glued into place
as a final touch i added an rgb led
strip onto the back
to create some accent lighting on the
wall behind it
with that all done i just needed to fill
the cooling water circuit with water
and hope that i didn't drown one of the
parts
luckily there were no major leagues
there was one slow leak on the inlet to
the first cooling block
probably because of the twist and
pressure on the tube to get to the
radiator
i clamped the tube with a small cable
tie and the leak stopped
all the cooling water loop needed now
with some colour
[Music]
i prepared a copy of raspberry pi os lut
on seven micro sd cards and a copy of
raspberry pi os on the eighth for the
master node
i could then power up the cluster and
check that they're all booted up
the system was initially quite noisy as
the air bubbles worked they were out of
the cooling water loop
but it eventually settled down
[Music]
the display is a nice way to visualize
stats for the cluster here i'm just
running the script i used previously to
display the cpu temperature of the
master node
i'm not going to get into the software
side of the cluster in this video
as there are a number of options
depending on what you'd like to do with
it and how experienced you are with
network computing
but i'll be sure to cover that in a
future video so make sure that you
subscribe to follow my future projects
i hope you've enjoyed following this
build with me please leave a like if you
did
and turn on notifications to follow my
future projects