Young Engineers: Class 3 Catapult - Sturdy and Fun DIY Engineering Activity for Kids
Summary
TLDRIn this video, Lance demonstrates how to construct a class 3 catapult using craft sticks, cubes, and rubber bands. He explains the lever principle behind it, detailing each step from assembling the base to attaching the arm and rubber bands. Lance also shares tips for optimizing the catapult's performance by experimenting with different projectiles and adjusting the arm's length, emphasizing the impact of projectile characteristics and the arm's potential speed due to its distance from the fulcrum.
Takeaways
- đš The class 3 catapult is a demonstration of a class 3 lever, utilizing a fulcrum, load, and effort.
- âïž Start by cutting or breaking three craft sticks in half using pliers or wire cutters.
- đ Connect two regular craft sticks with one half stick piece and glue additional sticks to form the base structure.
- đ© Build triangular supports on the sides of the base and add half stick pieces to the top of the triangles.
- đïž Create a catapult arm by gluing two craft sticks together with a third one in the middle.
- đ Attach the arm to the base using a thin dowel as a hinge, ensuring the arm can move freely.
- đ Loop rubber bands around the catapult arm to provide the necessary tension for launching.
- đŻ Attach a plastic cup to the end of the catapult arm using both glue and tape for stability.
- đ Experiment with different projectiles to find the optimal density, weight, shape, and size for distance.
- âïž Adjust the length of the catapult arm to increase speed and performance, considering the trade-off with inertia.
Q & A
What is the main concept demonstrated in the video?
-The video demonstrates how a class 3 lever works using a catapult as an example.
What materials are needed to build the catapult as described in the script?
-The materials needed include craft sticks, hot glue, a pair of pliers or wire cutters, a thin dowel, rubber bands, and a plastic cup.
How many craft sticks are cut in half at the beginning of the project?
-Three craft sticks are cut in half at the beginning of the project.
What is the purpose of the gap between the two cubes with holes on the base of the catapult?
-The gap between the two cubes with holes is left open to accommodate the dowel that will act as the hinge for the catapult arm.
How is the catapult arm constructed?
-The catapult arm is constructed by creating a beam that's two craft sticks long, connected in the middle with a third craft stick, and repeating the process once more.
What role does the thin dowel play in the catapult's mechanism?
-The thin dowel acts as a hinge, allowing the catapult arm to move up and down.
How are the rubber bands attached to the catapult arm?
-The rubber bands are looped around the catapult arm, pulled under the stop bar at the top, stretched out, and looped back over the arm again.
What is recommended for the catapult's projectile, and why?
-Foam cubes are recommended as projectiles because they are dense enough to go far but not likely to break anything, making them suitable for indoor use.
What factors can affect the performance of the catapult when launching projectiles?
-The density, weight, shape, and size of the projectile can significantly affect the catapult's performance.
How can the length of the catapult arm impact the catapult's effectiveness?
-A longer catapult arm can allow for faster movement due to greater distance from the fulcrum, but it may also require more energy to move and might need additional or different rubber bands for optimal performance.
What are two things viewers can experiment with to improve their catapult's performance?
-Viewers can experiment with different projectiles and the length of the catapult arm to improve performance.
Outlines
đš Building a Class 3 Catapult Model
In this video, Lance demonstrates how to construct a class 3 catapult using craft sticks and other simple materials. The process begins by cutting craft sticks, connecting them with hot glue to form the base, and ensuring the alignment of holes for the pivotal movement. Lance then constructs the catapult arm, which is a beam made of craft sticks, and attaches it to the base using a thin dowel as a hinge. Rubber bands are used to provide the necessary tension and power for launching projectiles. Lance suggests experimenting with different projectiles and adjusting the length of the catapult arm to optimize performance. The video concludes with a demonstration of the completed catapult launching foam cubes.
Mindmap
Keywords
đĄCatapult
đĄClass 3 Lever
đĄFulcrum
đĄEffort
đĄLoad
đĄRubber Band
đĄProjectile
đĄDowel
đĄInertia
đĄEnergy Transfer
Highlights
Introduction to the Class 3 catapult as an example of a Class 3 lever
Instructions to cut or break three craft sticks in half
Connecting two regular craft sticks with hot glue
Gluing two regular cubes at the corners above the half stick piece
Creating a base with cubes and ensuring the holes line up
Building the triangular supports on the sides of the base
Gluing half stick pieces onto the sides of the cubes
Building the catapult arm with two craft sticks connected in the middle
Gluing a regular cube and a cube with holes onto the catapult arm
Installing the arm onto the catapult using a thin dowel
Securing the arm's movement with the dowel as a hinge
Adding rubber bands to the catapult arm for launching
Attaching a plastic cup to the catapult with both glue and tape
Launching the catapult with a foam cube as a projectile
Experimenting with different projectiles for distance and performance
Exploring the impact of catapult arm length on performance
Considering the trade-off between arm length and required energy
Conclusion and invitation to watch more videos
Transcripts
[Music]
hey my name is lance
the class 3 catapult is a great example
of how a class 3 lever works where
there's a fulcrum on one end
the load on the other and the effort is
somewhere in the middle
so let's get started first cut or break
three craft sticks in half you can do
this with a pair of pliers
or by cutting with a pair of wire
cutters first connect two regular craft
sticks together using hot glue
and one of the half stick pieces flip it
over
then glue two regular cubes at the
corners that are above
the half stick piece and then glue two
cubes with holes onto the other end
making sure that the holes line up then
glue more sticks all along the sides of
the base
and on the top
make sure not to glue any sticks in this
gap between the two cubes with holes
next build the triangular supports on
the sides
of the base
and glue two regular cubes to the top of
each of those triangles
then glue the remaining half stick
pieces onto all four sides of these
cubes
[Music]
okay now we need to build the catapult
arm create a beam that's two craft
sticks long and connected in the middle
with a third craft stick repeat one more
time
[Music]
then on one of the beams on the side
that has the two craft sticks lined up
with each other
glue on a regular cube in the center and
on one of the ends
[Music]
then glue a cube with holes onto the
other end making sure that the holes are
pointing off to the sides of the beam
like this then glue the other beam on
top of all three of those cubes
okay to install the arm onto the rest of
the catapult we first need to get
a thin dowel and cut or break it to size
so
it's the same width as the base
now put the catapult arm through the
middle of the base with the cube
on this side put the dowel piece through
the cube with holes
then put one end of the dowel through
one of the cubes with holes on the base
and carefully pry the base apart so it's
wide enough
for the dowel to fit into both of those
cubes
[Music]
the arm should be able to move up and
down on this hinge
okay next we're going to add the rubber
bands loop it around
the catapult arm then pull it under
this stop bar at the top stretch it out
and loop it back over the catapult arm
again
now when the arm is pulled back the
rubber band gets stretched out
and when released you'll snap the arm
forward the last step
is to both glue and tape a plastic cup
on
if you use just glue or just tape then
the cup will break off
when the catapult is launched to launch
the catapult load your projectile of
choice
i like using these foam cubes because
they're dense enough to go far but
they're not going to break anything
then use one hand to hold down the base
while the other hand
grabs the cube at the very end of the
catapult arm pull all the way back
and then just let go okay so that's how
to build it
now there are two things that you can
experiment with to make your catapult
work even better
the first thing are the projectiles i
use these foam cubes because i can shoot
them indoors without breaking things but
they are not the best
thing to fire from the catapult if
you're trying to go for distance
try shooting different things out of the
catapult to see what can go the farthest
the density weight shape and size of the
projectile makes a huge difference in
how well the catapult can perform
and the other thing that you can tinker
with is the length of the catapult arm
so right now when i pull the capital arm
back and then let go
the energy from the rubber bands is
accelerating this cup up
and forward but if the catapult arm was
longer
then it could go faster because when
things are farther away from the axis of
rotation
or in this case the fulcrum they will
move at a faster speed
however a longer catapult arm is going
to be heavier and it's going to have
more inertia or it's going to take
more energy to get it moving so you may
need to add more rubber bands or
different kinds of rubber bands
to best take advantage of that added
length okay that's all for this video
thanks
so much for watching and i'll see you
next time
um
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