How to Make a Gravity Puzzle (Brain Game)

here’s a little brain game you can
easily make to impress the smartest
people you know the idea has been around
forever but most people still can’t do
it the challenge is simple just balance
these 14 nails on a single nail head
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you
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for this project I started by making a
template for a platform design I want to
try if you like it you can have it for
free I’m getting ready to take this to a
piece of wood and I want these edges
flush put a little overhang on these
others
I found a 3/4 inch panel of birch wood
in a scrap pile at the home-improvement
store and my paper template goes right
in the corner a little duct tape will
hold it in place just enough to help me
cut holes for some nails a total of 15
holes for 15 nails I’ve got a 9 64’s
inch drill bit that looks about the
right size so that goes in the Chuck of
my drill press and once I’ve got it in
secure I’ll drill a test hole in some
junk wood to double-check these 3-inch
framing nails will fit I can manipulate
the nail easily and the hole is still
tight enough to support the spike firmly
in place
perfect lowering the bit next to the
edge of the board will help me gauge the
depth of the hole and I can set these
nuts to stop the press from drilling any
deeper I think I’m ready to drill some
holes I’m being careful to drill all 15
markers to the same depth and before I
move on I’ll insert a nail in each hole
and check the tops of the nail heads to
see if they’re all level looking good
let’s move on the nails come out and
it’s over to the chop saw to cut the
other two sides off the template these
cuts are good and I’m happy with it so
far but let’s go one step further and
take it to the router table for some
finishing work I’ve got a 3/8 inch
beating bit and I’m testing the profile
cut on some scrap wood it looks like
that’s going to work so I can place the
block with the nail holes facing down
and carefully router the edges this bit
is spinning at 20,000 rpm so I have to
be very careful not to lose a finger
here okay the edges are done but a
little furry so I’ll sound that off with
some 100 grit sandpaper then hit the top
as well to get it ready for some color I
like how it’s looking now so time to
grab some leftover stain and shake it up
wearing gloves of course this is a
rosewood color stain and one of my
project nails will help me get the lid
off I’ll use a rolled up paper towel to
apply the stain to the bottom top and
edges making sure every surface gets a
liberal coating this will soak for about
3 minutes then I’ll use another paper
towel to remove the excess so that it
looks like this after about 2 hours of
drying I’ll insert a nail in the center
hole and grab some wood finish that will
seal the wood and give this
somewhat glossy look when the sides are
all sprayed I’ll prop it up to dry for
another couple of hours if this looks
like more work than you want to put into
this project you could always just grab
any old piece of wood and a hammer and
nail it in just about anywhere it’s as
easy as that but maybe you don’t have a
hammer
go find a rock just a couple of taps and
you’re ready to go if you don’t have a
rock how about an attractive assistant
you can use any method you can think of
as long as your nail is straight up like
this alright it looks like the finish is
dry and we’ve got the nail set in place
now you can challenge your friends to
balance all of the outer nails on the
lone inner one all the nails have to
balance at the same time and can only
touch the center nail head I’ve seen
some pretty creative attempts at getting
this to work
I say attempts because typically it’s
fail after fail after fail when your
player is sufficiently discouraged and
claims it’s impossible this is where you
get to show off your brilliance here’s
the super simple pattern that was
discovered long long ago and works
amazingly well lay one nail on the table
and mesh the other nails over top one
after the other like this until you have
six nails laid out on either side this
last nail goes on top pointing the other
direction and the pattern is complete to
make this effective grab the bottom nail
on both ends with your middle finger
tips and while lifting slowly use your
thumbs to hold the top nail down until
all the nail heads catch at this point
you can remove your thumbs and place the
entire structure in position well that
was easy
the center of gravity of the entire unit
is lower than the balance point making
this amazingly stable I also discovered
that the nails can be compacted and even
more nails added I just added 9 more
nails for a total of 23 and it’s still
holding firm I just made another stack
of 22 nails and I’m seeing if I can get
them to balance on top a little shifting
but they’ve held I’ll take my chances
with another group of 22 and now this
structure is up to 67 nails when I try
one more stack of 22 spikes
it’s about finished but wait he had
actually stayed up well there you have
it
89 nails balanced on one nail head at
this point the center of gravity is high
and the
bass is narrow so it takes mad ninja
skills to balance anymore I even got
this to work with stacks of up to 15
matches and even when they were lit on
fire they held their place on top of
those little matchsticks amazingly well
how many nails can you get to balance
that’s it for now if you liked this
project perhaps you’ll like some of my
others check them out at the king of
random calm
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you
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