Hey everyone, Jason here. Today it is shark day! LEGO recently released this
Deep-Sea Creatures Creator 3-in-1 set and as soon as I saw the shark on
it I knew I wanted to try and make this shark swim, and even though I already
built a swimming shark last fall, it was based on the Forma mechanism and for
this shark I really wanted to see what kind of mechanism I would come up with
if I were to develop it from scratch myself, and this is what I came up with.
Now, the first thing you might notice is that it is relatively un-decorated and
that is because I really just want to focus on the mechanism and keeping it as
simple as possible, because I really like the design aesthetic of the shark and
the crab in the original set, so I really didn't want to detract from them.
So, let's take a closer look at what is going on. In the front we have a main
drive shaft, which can be turned using this crank on one end and I actually
designed us so you can mount that crank on either end of the drive shaft. Or you
can connect a motor to it as you saw in the introduction. That drive shaft drives
these two crank shafts, each of which drives two pistons which are these grey
liftarms here. At the end of those pistons are these sliding bricks, and on
top of those sliding bricks are mounted two liftarms. The front two pistons
control the position and the orientation of this liftarm and the rear two
pistons control the position and orientation of this lift arm.
For cranks, I'm actually using these pulley wheel pieces, which have six holes evenly
spaced along the perimeter which means that each hole is 60 degrees offset from
the one beside it and so that I can just mount a pin in
one of the holes and use that as a crank. As a result each piston is 60 degrees
behind the one in front of it in its rotation cycle, which is large enough to
give us some nice noticeable movement in the shark, but small enough to make that
movement nice and smooth. The front section of the shark is mounted directly
on to this front liftarm using this transparent antenna and the rear section
of the shark is similarly mounted onto the rear lift arm. The center section is
unsupported from the base and it's just constrained by the front and the back
sections of the shark. I did have to replace a few pieces in the shark. In the
original model it's using these tight ball joints between the sections and so
I had to swap them out with these loose fitting ball joints, so that the shark
could move freely. I've created building instructions for this model if you'd
like to try and build it yourself, and they also include the changes that
you need to make to the shark itself. There are a couple of things to note. One
is that when you are connecting the pulleys to the crank shafts you'll want
to pay special attention that they are all oriented identically. The other thing
is that the shark segments are connected to the liftarms using a single stud so
they actually can be rotated quite a bit, and you'll just want to make sure that
they are oriented the same as the lift arm they're mounted on. And that is about
all there is to it for this model. I had a lot of fun with this one. I really do
like these Creator three-in-one sets. As always thanks for watching keep on
building and I'll see you next