Hi I'm Jonathan and this is rad-head
Today I'm building this spinning water tank
that demonstrates the effects of the centrifugal force by creating this cool convex shape.
Let's start building
I started by making the tank itself.
I've cut some 4mm clear acrylic into two rectangles and four thin strips
that will make the edges of the tank.
I assembled the tank and held it together with spring clamps
once pleased with how everything aligned I fused the sides together with acrylic solvent.
Ideally I would have used a thinner solvent that will actually wick into the seam
but this is all I had.
I mixed a cup of water with a few drops of green food coloring for extra contrast
Once the tank has fully cured, I started filling it up.
First I marked the desired water level, which is half way up the tank
and used a syringe to fill it up to that line.
Now it's time to add the last piece of acrylic and seal this water tank for good.
There's no going back from this point.
This thin water tank needs to spin freely, but it has such a low moment of inertia
it won't hold a spin very well.
So I decided to make the tank holder from a heavy chunk of steel
that will make it spin much longer.
I milled a 12mm slot in the middle of the steel blank for the water tank to securely sit in.
machining steel always makes me think how crazy it is to cut a piece of steel
with just another piece of steel that is slightly harder.
The harder material always wins
I flipped the piece around and drilled an 8mm hole part way through.
Instead of using all the fancy gauges on the machine
I just marked the depth with a piece of blue tape.
I then gave it a couple of coats of white spray paint.
I've cut a piece of 8mm shaft to length with my angle grinder.
By the way I ended up using a 15cm long shaft and not 10 as you see me cut here.
Now it's time to make the base for this whole contraption.
I wanted something heavy that will easily support the rotating mass
so I decided to cast it out of concrete.
I still needed to somehow attach a couple of bearings to it in order for the tank to spin freely
and I decided to embed this 3d printed bearing holder in the concrete mold
which is just a plastic cereal bowl.
I prepped my work area before starting the messy part of the casting.
Giving it the final touch and let's mix some concrete.
I mixed the concrete following my grandma's famous recipe.
One part white cement.
Two parts sand.
One part plaster, which makes the concrete cure faster.
And grandma's secret ingredient
diluted PVA glue
I mixed the dry ingredients thoroughly and added the glue and some water
until I got to the consistency of gluten free oatmeal.
I carefully filled the mold using the stirring stick to push the concrete into every nook and cranny
I then used a power sander to vibrate out any air bubbles.
I noticed that the mold started rotating counterclockwise when vibrated.
It seems that no matter what I try, I can't seem to make it rotate clockwise.
I'll have to look deeper into this one.
If you have any ideas, feel free to comment.
I leveled the top part with a straight edge and now this needs to cure for 24 hours .
If you're impatient like me you can simply put it in the oven on high heat for 10 minutes.
I'm kidding of course.
Or am I?
Demolding the base reveals a very smooth surface
although I still had some bubbles on one side.
I was very pleased by how the bearing holder was integrated into the concrete.
I intentionally made the holes a little tight, so I lightly heated the part to get a really snug fit.
I assembled everything together, by first inserting the water tank into the steel holder
then I slipped a small piece of tube on the shaft to act as a stopper.
Now I can finally place the tank on top and give it a spin.
The tank spins freely and takes quite a long time to come to a rest
thanks to the extra mass of the steel holder
I played with different ways of spinning it, and found that I can reach very high speeds
by wrapping a string over the shaft and pulling it quickly.
You could calculate the RPM of the water tank by examining the obtained curve.
I plan to do exactly that including a pseudo rigorous analysis of the physics behind this demonstration
on my next video, so stay tuned.
Off camera I made two more water tanks.
The water level in these tanks reveal the full 3d surface created by the rotating liquid.
The cylinder gives a very clear view of this surface.
My original tank simply displays a cross section of it.
The cube however lacks the continuous rotational symmetry
and the edges are further apart than the faces
this gives it its unique look, however this is of course still the same surface
as with the other tanks.
That's all for this one, feel free to comment below
I'd love to know what you think about this project
As always, I have plans and 3d printable models over on my website
the link is in the description.
If you like my projects, and want to help me make more of them
consider supporting me on patreon
Until next time
Bye
For more infomation >> Building a Spinning Water Demo - Duration: 5:20.-------------------------------------------
Aesthetic Training Tips | How to Build a Shredded Chest - Duration: 5:03.
what's up everybody this is IFBB Pro Santi Aragon and I'm here with muscle
and strength and I'm gonna take you through my three favorite aesthetic
chest building exercises so for the first chest exercise to build an
aesthetic big ole barrel chest first step of this exercise is to pick an
appropriate weight you want to start a little bit lighter before you get into
your heavier movements just so that you can get used to this style of press I
pick a incline bench for this movement and when I roll back with the dumbbells
you're gonna see that I'm gonna start in a normal fly movement but as I'm
pressing the weight up you're gonna see that my pinkies are gonna start coming
inward to squeeze the chest and as I'm coming back down I'm gonna be rotating
them back again in a fly movement here we are in the fly movement I'm gonna
press up and I'm gonna rotate my pinkies what this is gonna do is this is gonna
squeeze the chest and as I'm rotating back down I'm in another I give them in
a press movement right here and this is stretching out my pecs so I'm coming up
rotating squeezing opening up opening up and I'm stretching
so not only can you press some pretty heavy weight because this is a hybrid
press movement but you're also utilizing the squeeze if it was a fly movement too
so you're kind of getting best of both worlds on this movement exercise number
two for anesthetic chest is gonna be a fly movement the difference between this
fly movement and any other fly movement that we do is going to be the way that
we're gonna be doing each rep it's gonna be a holding a pause at the top of the
movement and then it's gonna be descending slowly back to the bottom
keeping constant tension on the muscle group and then coming back and again
pausing at the very top another difference between this and any other
fly movement is that I'm gonna concentrate on bringing the bar much
higher on my chest versus right in the middle part of my chest the reason why I
do this is because if you look at any of the classic guys back in the 80s and 90s
you can see how crazy their upper chest was and I really do believe that any
type of upper chest movement is going to hit the mid and the bottom part of your
chest and the hardest part to build is the upper part of the chest so I'm gonna
go ahead and demonstrate this movement for you standing very comfortable I'm
gonna come up top and you can see how I'm squeezing up I'm just gonna see on
squeezing upwards I'm not down my elbows not down it's
actually kind of up so that I can put more stress on the top part of my chest
chest is up so here we go we're gonna pause at the top boom one two three come
down one two three up one two down one two
I'll do this for about 12 to 15 reps and at the very end when I can't do any more
I blast out about five regular sets this is gonna be something that's going to be
focusing on the lower part of the chest and I choose this as the final exercise
because we're gonna be doing a finishing type set here which is gonna be
extremely high reps so what I usually do is I'll pick a weight that I think I
could handle and I'll just feel it I'll touch the weight if I'm ready and I
think I could handle it the goal is to go to 50 so it's very basic
this machine pretty much tells you where you need to go and the key is that at
the top of the movement you're making sure that you're squeezing
it's like any other chest movement this particular movement at the end of your
chest routine is not going to require three or four sets like a standard
movement this is gonna be a touching so you're gonna see if you can handle the
weight and then it's gonna be one all-out set of 50 repetitions and there
you have it those are my three favorite chest exercises thanks for watching
please comment and subscribe below
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