Oh, safely! Nobody wants safe things, don't want to be safe.
It's Tod from Tod's Workshop and Tod Cutler here and we are back with the trebuchet
and bowling balls and this time today, tracers. So we're gonna fit them with smoke grenades and that
should make them easy to spot, but the main thing is thankfully we still have a trebuchet because
look at this footage here of this bucket jiggling about. It's going crazy. The problem with that is
that the geometry of this machine was meant to do one thing and I'm now trying to make it do
something else, so I have to make the arm longer and that is why we are here today.
The reason that it is important is this ball is going 130,140 meters, but the energy that I'm
taking and and putting in that counterweight is not getting transferred to the ball and that is
the problem. So the ball doesn't go as far and the counterweight energy has to get dissipated
through the machine and that is what the danger is because it might just break itself apart.
So we're going to that by just extending the arm and I'll talk you through that process,
but before we carry on, help the trebuchet, help the channel keep going, check out my website,
check out the t-shirts. All right let's get down to it. I now have to fit an extension onto the
end of this arm so the first question is why am I doing it? Well the geometry of this machine now
for the weight of the counterweight and the weight of the thing I want to throw, is now wrong and you
could see that from the buckets the inability for it to transfer the energy into the ball and
the dissipation of the energy through the frame which is really dangerous, so I have to solve
that problem and that's important because in three weeks time I'm renting this out to a TV company
and the last thing I want is for it to break. So I'm going to put the extension on of about 1.2/1.3
meters that should make it work much better. Now handily I've got this big steel bracket
arrangement here that I put for an adjustable pin, so I can use this as the foundation, but I have
to be careful to not replace one problem with another problem because actually the effective
weight of that ball as it's being whipped around on a four and a half meter/five meter arm, the
effective weight of that ball is going to increase massively from the seven kilos it is to maybe two
or three hundred kilos. I don't really know, so this has to resist any buckling and any bending
otherwise I'm just going to break the thing in a different way. Anyway, see you in a bit.
I'm back with a nice big chunky arm extension so I'm just going to whack it into place, bolt it up.
It's back for hopefully the last round of changes now, so I've put a four foot a 1.2 meter extension
on the arm, repositioned the trigger and then the other big change is that the two foot wide, the
60 centimeter wide gutter that the projectiles would slide down; I needed that before,
now I don't, so I've narrowed it down to a V and that'll hopefully improve accuracy. Ready to go.
Here we go
Hey so this is the look of a disappointed Tod. It didn't go that far, the pin angle was too
far forward, it held the ball too long. It's an easy fix, we'll just bend it and go again,
but for the first shot I really wanted it to fly. Not today. Let's try again. So here's the
big news after the first shot; it stayed in one piece, the arm worked, it didn't break.
Rock solid. Good number two, the basket, absolutely much calmer, much gentler
and that's exactly what you want, so the force is now going into the shot not into the frame
okay so that is really good news and you can see that by just contrasting now with before.
Third thing, it didn't go very far but I've actually replayed it now on my laptop and I can
see that it comes up way past the 45 degree point before it releases and it's actually at 22 degrees
of vertical give or take a little bit so actually we've got to pull the pin right back so that again
that is brilliant news because it didn't shoot very far but there's a good reason for that.
Number four, the smoke a little bit Hmmmm, but anyway hopefully it'll improve things
here we go again. Nice!
I like it! Ah that was so much better, that was really good, but what I'm going to do before
I conclude, I'm going to review the release angles on it, I'm just going to see if we can
make any more tweaks, get anything any better than it is, but at the moment really pleased.
My machine is once more alive and ready to rock and roll. Back for the traditional conclusion.
I only did two shots today but the trebuchet held onto the second one for too long as well,
so it didn't release it really till it was about 50/55 degrees so the shot could go further than
it did today just got to bend the pin back a bit more. All the things about trebuchets,
it didn't go very far, bit disappointing about 120/130 meters so about what it was doing before,
but now the basket is calmer everything is better, energy transfer is better, so the potential of
the machine is better and it's going to stay in one piece and that's all I could ever ask for,
so I'm gonna be back next time, I'm going to re-tune it again, I'll have a chat with Daniel
over in the States. I think probably the sling needs to be a bit shorter try and work out what's
going on and we're gonna come back for more of this stuff. I'm still learning, I learn every
time I touch this machine but hopefully that'll be the end of the fixing now. See you again