Trebuchets

The Medieval Cruise Missile

Information

Specs

Work list

Research

Grading

 

 

Info

 Your team has elected to study and build a simple marshmallow throwing catapult. Known as a Trebuchet, (treb boo shay) this engineering wonder helped armies defeat castles during Medieval times long ago.

        The trebuchet is a collection of simple machines that rely on physics to accomplish their one goal:

  • to throw something far and accurate

        Trebuchets were able to throw a 200 lb. stone or a  "disease-ridden cow" over or through a castle wall,. This was accomplished from outside the range of the opposing archers. Eventually, the wall comes down, and the castle was defeated.  The trebuchet  was the atom bomb of it's time!

You will compete against other teams in class to knock down a "castle" wall made from soda cans. 

All info will be recorded on the Design Process Problem Worksheet.   Save it electronically into a team folder in the STUFF Folder on the computer desktop.  Fill out as necessary to record your work. Your research will be recorded on "Inspiration"  outline software.

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Specifications
  1. Use the links found in the Work list to look at smaller size trebuchets.  You may build ""almost" any size, but you are limited to time (approx.16 days) and  the size of the counterweight.
  2. The rule of thumb for the counterweight is that it should be 100 times the weight of your "bullet".  For example- if you wish to throw a marshmallow, the counterweight should be 100 times the weight of a marshmallow.
  3. You may use rubber bands to provide the power for the throw. 
  4. You may use a sling to hold your projectile, or a cup-like device. There are many differences, you must decide what you wish to build. 
  5. The competition involves 10 throws from at least 15 feet.  you will attempt to hit a wall of soda cans. The best % of hits will win.

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Work list:
  1. Select a team, brainstorm a name.
  2. Read and understand the Design Brief.
  3. Read and understand the DPPW. 
  4. Make a team folder in the Stuff folder.  copy (save as) the DPPW on the desktop and place in your folder. fill out the top area and step 1- Problem.
  5. Start your Research- step 2.   This involves understanding Trebuchets and medieval life.  Pass in your outline.
  6. Step 3- Solutions- Try these sites:

    Grey Company

    Siege Engine.com

    These sites have many small trebuchets that can be made in a short time.  Pick one or two out and ask Mr. G if they can be done. Each team will draw 6 thumbnail sketches,  these should include trebuchet shape, type of counterweight, and type of throwing arm.  Record the ideas you come up with for these design areas in your DPPW.  Pass in your thumbnails.

  7. Include these good design parts in your step 4- Best Solution drawing.  Use graph paper and draw an accurate scale drawing.  Include the design areas.  Be neat, your Trebuchet should look very similar to your drawing. Pass in your rough sketch.

  8. Build your Prototype- step 5.  Make sure it conforms to the activity specs.

  9. Once your prototype is built, test it.   Fill out step 6- Testing & Modifications, list any changes you made to your final solution. When satisfied with your design, test out your Trebuchet with marshmallows. . Record your %  for 10 throws at the can wall. 

  10. Lastly, record any changes you would make for the better, or figure     out     why your design did not work.  List these in step 8- Re-Design.

  11. skip step 7- communicate.  Take the end of activity Quiz. You may use your "Inspiration" outline for help in answering the questions.

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Research

Start your Research- step 2.  This involves understanding life in Medieval times.  Simply go to :

 Life in a Castle

Read this link, and research the info to create an "Inspiration" web outline.  This can be used during your end of activity Trebuchet quiz. Print and pass in your "Research".

The "Inspiration" program is found in Start/ Programs/ Inspiration k-12.  Be sure to save in your stuff folder.

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The competition will give each army 10 attempts to knock down the castle wall. Using a marshmallow, each "hurl" will be from a minimum distance determined at testing.  The wall will be a soda can wall 3 courses high.

 

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Trebuchet Model completed & tested built, not tested not completed
Research completed, good content lacks good content on topic not completed
DPPW complete missing no more than 2 sections missing more than 2 sections
Competition first or second competed did not enter
Cooperation helps team in all ways works 70% of time works less than 70%
Quiz 85% or above 70-84% less than 70%

A  24-30    B 18-23  C 13-17   D 13-16   F 0-12

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Extra rubric for Hovercrafts & Blimps:

replace the competition row above with:

H/C, Blimps

 neat messy not finished

 

 

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