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Designing and Building Trebuchets Created by: Dale Roy droy@mansd.org |
Introduction /
Task / Process / Evaluation / Conclusion /
Introduction
Imagine! It’s medieval
times and you are about to do battle with your sworn enemy. You have heard about the latest and
greatest invention in weaponry, a TREBUCHET!
To help protect your
lord and fellow villagers you decide to build your own version of the best
thing since the wheel.
In
reality, you are an engineer and it is your dream to build a working replica of
trebuchet. You search for ways to
fulfill your dream when you come upon…
Task
You are an engineering team
of two who has been hired by an eccentric family
who would like you to build a trebuchet for them. They have a large budget for you to do as you will and would
like you to complete everything by a very firm and specific timeline.
Of course they have requirements for you to follow
before you get to spend their life savings!
1.
Must keep a journal of your build process.
2. They want to see the plans drawn with a
scale before you start
building.
3.
Trebuchet needs to be built with in a
certain height and width
restrictions and must be made
completely of wood.
* you are not to use
nails to hold your trebuchet together
4. Physical science concepts need to determined and calculated as they apply to your trebuchet.
Process:
TEAM:
You need to pick a partner with in your own class. You will be able to choose your own partner however; I would recommend thinking to the past.
Have you worked with this person before? If so, how were they as a partner?
Did you end up doing all the work and they still got the grade?
Did you end up spending most of your time talking, laughing, and playing games rather then keep on task?
JOURNAL:
You will need to keep a
daily build journal for the duration of the project. For this journal you must include the following
requirements.
1. You must keep track of dates and
time!
Tuesday 6/28/05 started @
12:00pm ended @
3:30pm
2.
Your
first entry is to tell me about what it means to be
an engineer. Once you find what it means to be an
engineer record what kind of engineer your
team would
be considered.
LINKS:
Discover Engineering: Engineers
3.
Your
second entry is to give a history on the trebuchet.
* Follow the Five W’s. (who, what, when, where, and why)
LINKS:
Trebuchet a NOVA History A Brief History
4. Keep track and document what everyone is
doing and
project progress. Try to be detailed, write down things
you tried, successful experiments, failed
experiments,
modifications as a result, frustrations
anything that
relates to the build and the build only.
5.
Follow the Journal writing sections of the Rubric
to
ensure that things are being done
correctly.
PLANS
Everyone
in the Engineering business from electrical engineers to civil engineers all
use a well organized plans of some type to help guide them. Your team should draw a well thought
out design for your trebuchet that can be easily followed by anyone in your
team!
1.
Plans
of your trebuchet need to be drawn on graph paper
2.
All parts of your trebuchet need to be labeled by name,
measurement, and units. All should be done in metric.
Ex: Throwing arm length
Fulcrum Height
3.
You
must provide a scale for your drawing and a key where it will easily be found.
Ex.
One small graph square = one centimeter
4.
Plans
need to be done and approved before you start
building your trebuchet.
5.
Follow
the Plan section of the Rubric to ensure that
things are done correctly.
LINKS:
Ripcord DETAILED Plans
( this does the individual pieces, you do not have
too do this)
Trebuchet Plans
( This is for example
only, you are to be more adventurous and come up with your
own.)
TREBUCHET
Now
it has come to the time where you much build your trebuchet. Remember to follow the plans your team
drew to the best of your ability.
These when built
incorrectly or correctly can hurt someone or something. You are under no circumstances to use
this on siblings, creatures and critters of any kind, vehicles, and anything
else that may come across your mind.
This is for class use and if used at home is to be aimed at inanimate
targets only!! It is assumed you
will follow all safety rules and precautions that apply to these types of
experiments.
1.
Trebuchet
Fulcrum Height: No Taller then 26
centimeters
2.
Trebuchet
Base: Longer then 32 centimeters.
3.
Trebuchet
Throwing arm: you will find the
height of the fulcrum will determine the length of the throwing arm.
4.
Sling
Length: Experiment to find the
best length.
5. Counter weight: Plan on using minimum of .5 kg. You of
course
may need to
experiment with this to find the proper amount
of weight.
6. Follow the Construction
sections of the Rubric to ensure that
things are done correctly.
PHYSICAL SCIENCE CONCEPTS:
It is time to talk about how the trebuchet works. Here you should be looking into what type of forces and energy that we covered apply to the trebuchet. These topics may or may not include the following: Newton’s first, second, third laws, friction, momentum, kinetic energy, potential energy, gravity, etc. You are not limited to this list, this is just simply to help guide you where to look.
Once you determine what applies to your project you must do the following:
1. Explain how a trebuchet works by talking about the forces and they types of energy that apply to the project.
2. Explain how each type of force and energy apply.
3. Calculate the amount of each force applied and energy being
used.
4. Follow the Scientific Knowledge section of the Rubric to
ensure that things are being done correctly.
Here are some links to help you determine what could apply.
Evaluation
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Teacher Name: Mrs. Roy |
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Student Name: ________________________________________ |
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CATEGORY |
A |
B |
C |
D |
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Journal/Log – Content 20pts total: - 5 pts engineering - 5 pts history 10pts other entries |
Journal provides a complete record of planning, construction, testing, modifications, reasons for modifications, and some reflection about the strategies used and the results. Engineering entry is fully explained and specific aspects of what they do are provided. History of the trebuchet is factual and accurate. All sources are cited for both entries. |
Journal provides a complete record of planning, construction, testing, modifications, and reasons for modifications. Engineering entry is fully explained and some aspects of what they do are provided. History of the trebuchet is some facts and is accurate. All sources are cited for both entries. |
Journal provides quite a bit of detail about planning, construction, testing, modifications, and reasons for modifications. History of the trebuchet is short with some facts and inaccurate. All sources are cited for both entries. |
Journal provides very little detail about several aspects of the planning, construction, and testing process. Engineering entry is a definition from the dictionary. Reader and student have no understanding of what an engineer really is. History of the trebuchet is short with some facts and inaccurate. Sources? What Sources? |
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Journal/Log – Appearance 5pts. |
Several entries made and all are dated and neatly. |
Several entries are made and most of the entries are dated and neatly entered. |
Several entries are made and most of the entries are dated and legible. |
Few entries are made AND/OR many entries are not dated or very difficult to read. |
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Plan 10pts |
Plan is neat with clear measurements and labeling for all components. A Key is provided with the defined scale. |
Plan is neat with clear measurements and labeling for most components. No key, but a clearly defined scale is provided |
Plan provides clear measurements and labeling for most components. No key and the scale are not clear, leads to some guessing. |
Plan does not show measurements clearly or is otherwise inadequately labeled. No key and no way to tell what the measurements are suppose to be. |
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Construction –Materials 30 pts |
Appropriate materials were selected and No metal at all was used except with the counter weight. The Requirements on height and base length were followed exactly. |
Appropriate materials were selected metal was used for the hook and to hold the string on the throwing arm. Requirements for base length and height were followed exactly. |
Appropriate materials were selected metal was used to for the hook, tying the string to the throwing are and a nail or two to hold pieces or tape is being used to hold a few places. The requirements of height and base length are off by half an inch. |
Inappropriate materials were selected, metal was used liberally or tape was applied liberally to hold the trebuchet together and the string to the throwing arm. Height and base length requirements are off by an inch or more. |
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Construction - Care Taken 10pts |
Great care taken in construction process so that the structure is neat, attractive and follows plans accurately. |
Construction was careful and accurate for the most part, but 1-2 details could have been refined for a more attractive product. |
Construction accurately followed the plans, but 3-4 details could have been refined for a more attractive product. |
Construction appears careless or haphazard. Many details need refinement for a strong or attractive product. |
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Scientific Knowledge 25pts |
Explanations by all group members indicate a clear and accurate understanding of all the physical science concepts. All concepts as to how they apply to the project are fully explained leaving out no detail. Math was worked out fully and 100% - 90% Correct with proper units. |
Explanations by all group members indicate a relatively accurate understanding of the physical science concepts. The concepts as to how they apply to the project are explained leaving the reader with one or two questions. Math was worked out fully with minimum of 80% accuracy no missing units. |
Explanations by all group members indicate relatively accurate understanding of the physical science concepts that are mentioned. Ones not understood are left out completely. If all are listed the reader has 2 or more questions to ask. Math was worked out but not well and missing some of the units. |
Explanations by all members of the group do not illustrate much understanding of physical science concepts. Ones not understood are left out completely. The ones that are understood are explained but reader is left with 2 or more questions. No math was even attempted. |
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Date Created: Jun 28, 2005 05:58 pm (CDT) |
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Conclusion
SUCCESS! You have built the greatest invention
of medieval times. You have saved
your lord and fellow villagers who are extremely grateful. Your lord has handed you a parchment
praising you of your achievement…
Reality
again, they may not be lords but the family is grateful for all your extremely
hard work. To thank you they hand
your team a certificate of achievement and pay you all handsomely.
