Hi. I'm Edd China and I love technology. Now, you may have seen me messing around
with old cars or strange vehicles but today I'm in beautiful Trondheim
in Norway to find out what this clever machining tool has in common with this huge building
in Taipei. Well, to find out we need to learn a bit more
about vibration, so check this out. Vibration is an oscillation around an
equilibrium point in a mechanical system. That might sound complicated but a stringed instrument can demonstrate
what that's all about. Energy is built up by stretching the string. When we release it,
what we get is an oscillation. A vibration that decreases
if no more energy is added. We measure the frequency
in the unit of Hertz. One Hertz is one event or wave per second. There are good vibrations and bad ones. A speaker, for example, would work
really badly without vibration. The same is true of an opera singer
or an echo sounder. But usually vibrations are undesirable. They consume energy, generate noise and
damage both equipment and people, which is why we use a variety of methods
in an attempt to dampen them. Everything from sound dampening all the way up to seismic base isolation
systems in large buildings. All objects have what's known
as natural frequency, which is the frequency at which the object
tends to oscillate when affected by forces like impacts, winds,
tremors or imbalance, for example. If the frequency is strong enough,
and within our hearing range, we'll hear a sound or a noise. In cars, which of course
is my specialist field, there are hundreds of different
solutions designed to dampen every possible kind of
unwanted vibration. When it comes to machining,
it's particularly important that vibrations are kept under control so I've come here to Sandvik Coromant, the leading company in vibration-reducing
technology for machining, to see how they do it. And for an engineer and tech nerd like myself this is nothing less than Shangri-La. So, Tormod, can you tell me what are
the challenges with vibration when it comes to machining? If you have a cylindrical tool,
approximately three times the diameter, that's the maximum length you can go
with a solid tool. - OK.
- And... If you have a damped tool,
you go much further. The steel has a certain stiffness,
approximately ten times the diameter. Steel has the end so you cannot go
especially further with steel. - So even with a damped tool...
- Even with a damper. Because the stiffness of steel
isn't high enough. And then you have to go with carbides. You have to reinforce it to get it stiffer. Wow! So carbide is actually the same material
that you'll be making the cutting tip out of. - Cutting tip, yes.
- So how on earth do you machine that? That is a big, big challenge. Because it's a really hard material and can
only be grinded with something harder. And that is diamond. Where is the damping bit? Is it all the way
through or is it just at one end? Of course the vibration is in the front so actually you'd like to put the damper
at the insert that would be more efficient. So it's placed as far to the front
as possible. OK, so then the damping magic, if you like,
is inside here. I can see some O-rings. Yeah, you have to work with three things. That is the mass, which is a damping mass,
because it's a tuned mass damper, - and then you have some springs.
- Yeah. Because you need to tune it
to the right frequency. OK. And then you have something to add damping,
which is oil. Oil? So it's very much like a car suspension
where you would have your spring obviously to keep your wheel going up
and down, whatever. But then also you'd have the oil in,
the damper itself - to absorb that vibration.
- Yeah. Silent Tools uses a damping technique
known as tuned mass damping where a relatively light counterweight
inside the tool absorbs kinetic energy of vibrations and uses a compensating frequency to
eliminate them mechanically rather than converting them
into noise and heat. Hence the name Silent Tools. Now, Dan, these tools come in all shapes
and sizes, I guess, so is this the smallest that you manufacture? Yeah, this one is the smallest. It's 10mm in diameter
and 10xD in length. Wow, OK, so that is actually going quite long and you've got all the damping technology
in the tip of this, as before? - Yeah.
- That's amazing! That is really crazy. So that is one extreme. So what would be the longest tool
that you could do? - Measured in xD.
- Yeah. That's the longest tool we make. Right, and what is that? - 18 times the diameter.
- 18xD?! And 100mm in diameter. Wow! That is amazing!
That really is pretty extreme. Would you say that was the most extreme tool
that you do? Not really because it's still quite stiff. - Because it's...
- Because it's 100mm diameter. Exactly. This one is more extreme
and harder to make to work. Oh, I see. Because it's less diameter and 14xD. Obviously in this world of computers and
stuff, is an active tool where you're headed? So you'd know exactly what's going on
all the time. Yeah. The tool over there
that we looked at before. - Oh, that's it?
- That's it. Wow! OK, so that's obviously connected up
to this machine. So that's what the screen is. So can I try and deflect it?
See what happens? Yeah. You can try and push it. It sounds like a challenge, but... Oh, wow! Look at that. So what am I managing? That's 0.4mm. 0.4mm. That sounds... I mean, you know, I'm giving it some. - Can we see it actually operate?
- Yeah, sure. Is it like a normal lathe?
You'd actually have to set the tool up to make sure it's the right height
and the right orientation? Yeah. That is what the operator
will start with, to look at the tool set-up. That's a digital level. So it knows where it is in space as well? Yeah, and we have
the live viewer screen here. - So you've got temperature as well?
- Yeah. It shows us the deflection
and the load of the bar. - The load is very important to know.
- Of course. And then we also measure the vibration level
of the tool which is very related to the surface
you actually get in there. So these are also two very important features
that we measure. Yeah. Fire her up, please. Remember the skyscraper at the beginning? Well, it's called Taipei 101
and it's located in Taiwan. And what's interesting is despite
its enormous size difference it actually uses the same system
as Silent Tools, tuned mass damping, to counteract vibrations and oscillations
brought on by hurricanes and earthquakes. Their counterbalance, however,
is slightly bigger, measuring 5.5 metres in diameter and
weighing in at 660 tonnes. It even comes with its own mascot,
the damper baby. Wouldn't it be cool to make a model to see
exactly how tuned mass damping works? Well, I thought so, so I got my friends here
at Sandvik Coromant to build one. - Hi, Grethe.
- Hello, Edd. How's the machining going? - It's going very well. Want to see?
- Yes, please. - Get your glasses on.
- Absolutely. Look at that! That's fantastic. Yeah. Gorgeous, right? Thank you, Grethe, that is wonderful. - There you go.
- Thank you. Look at that! I have Grethe's part, which is great so just maybe sand off the edge here? Yeah. So, Carin, shall we start attaching this? There we go. Any good? Yeah. One more to go. Nice! So that's pretty good. Right, so now obviously we have our tower
so there's a small hurricane. - Yeah.
- Or maybe an earthquake. So it would be really good to actually
maybe measure the frequency to see what it is at the moment because
it's going to take a long time - to die down on its own, isn't it?
- Yeah, it's a good idea. So now we have the laser spot here. OK, for testing. And this is a Doppler laser so this one
measures the velocity. Oh, that's clever, OK. - So now we can give it a small push.
- OK. And then we just wait. Yes, obviously that's where Carin caused
an earthquake or a little hurricane. And it's coming all the way down and down
and down and down. It's taken so long the machine has got bored
and just stopped measuring it. So in the same way with a Silent Tool obviously we need to have a tuned mass
and then we need to damp it. So what we need now is our little ball. So our 660,000kg ball down into
a little tiny thing and then we can put that into position and then once it's in position
we need to tune it, presumably just to get it so it vibrates
in relation to the tower. Yes. Now we want the frequency of this one
and the frequency of the pendulum... - Yes, OK.
- ...to be quite similar. OK, so let's have a look at our pendulum. What is this weight made of? This is wolfram or tungsten. Tungsten?
So it actually is very heavy for its size. Yes, a very high density. - Thread it through here.
- Yeah. Just put that down there for a start so let's just get it so that it locks
the right way. - There, do you think?
- Yeah. Now you can see it. - OK, so it's got quite a fast return.
- Yeah. So now if we lower that down. I can change the frequency of the ball. So now if we rock it again. - That's a much more relaxed frequency.
- Pendulum. So now it's more in tune with the building so this is exactly effectively
what you're doing inside the tools. You're having to change, or tune that mass
so that it actually does this transfer. - I think that's quite OK.
- Yeah. That's really interesting. So you can see
the energy from the tower being transferred into the pendulum but
then actually transferred back out again. - Yeah.
- Excellent. So the next thing is we need
to damp this somehow. So obviously in the Silent Tools you use a special liquid
like a viscous liquid to do that so presumably we can do this
the same sort of way? - So here's...
- Our magic fluid. ...some oil we can use to get some damping
into the system. Probably completely top secret. The magic ingredient. It will be really interesting to see
how this will work. Give it another push maybe. Please, yes. One of your finest earthquakes. - Oh, wow! Do that again.
- Look at that. So in a car obviously the trick
with the suspension is basically one and a half bounces and just do that again,
you've got one and a half bounces. - Yeah.
- Look at that. That's amazing! That is incredible. So our model tower is
now completely resistant to hurricanes and earthquakes
thanks to tuned mass damping. And so clearly the physics works whether
your tower is nearly 500 metres tall, whether it's a metre tall
or whether it's in a tiny tool. I think we deserve a little round
of applause. So now you know the similarities between
this Silent Tool and Taipei 101. They're both subject to the same
laws of physics and both damp vibrations with the same method
tuned mass damping. Until next time.
I miss Wheeler Dealers
Mike couldn’t stand his fame