Catapult/Trebuchet Build
Goal – The objective of this catapult/trebuchet build is to create an original design build and fire a
weighed piece of clay a determined distance. There will be a specified amount of materials given out
and you will be required to project the clay a certain number of feet, with the main goal being worth the
most points, shorter/further will be less as you move away from the main target.
1. Research the various types of catapults/trebuchets and determine which one you would like to
build in order to meet the criteria above.
2. You can only use the materials given out by the teachers and nothing more.
3. You will be required to complete the following items on this 2nd page
4. Concern yourself with safety – make sure you are following proper safety procedures in the
Manufacturing lab.
5. Build the machine to be adjustable. It's very hard to design a trebuchet to be optimal on paper.
Instead, you will be test firing the machine many, many times with different arm lengths, sling
lengths, etc.
6. In particular, the release pin angle must be adjustable. One line of the sling will slip off this
device to release the pumpkin at the critical point in the swing. It must be possible to adjust the
pin angle and to lock that pin down so that is will keep the adjustment. This is a safety issue. If
the pin angle slips, you could fire the pumpkin vertically and kill yourself.
7. How are you going to pull the arm back?
8. Finally, there are a lot of elegant ways to optimize the design. The main goal again is to launch
clay a determined distance and be accurate as well. So it’s not about going the furthest as it is
distance and accuracy.
http://files.solidworks.com/video/Sim_PumpkinChunkin_Video.html
http://virtualtrebuchet.com/Trebuchet.aspx
http://armorgames.com/play/3614/crush-the-castle
You will be graded on the following items:
1) Design Plan
2) Data Analysis
3) Conclusion
1.) Your Design Plan Must Include:
1) A list of materials used (should be bulleted)
2) A diagram of your catapult. The diagram should have all dimensions labeled (including units)
and should be neatly drawn. Your diagram should be drawn on plain white paper and should fill
most of a single page.
2.) Your Data Analysis Must Include:
1) Data table that includes time of flight(s), distance flown in horizontal direction, and angle of
launch. You must test at least 3 different angles using 3 replicate trials for each angle.
2) A value for the average initial velocity of the clay and an explanation of how initial velocity of
the clay was determined. (Refer to class discussion regarding determination of initial velocity)
3) How did changing the angle affect the characteristics of your trajectory? The initial velocity?
3.) Conclusion:
Your conclusion should include an overview of your findings and describe any sources of error that
might be present. Give some examples of real life projectiles whose landing spots must be carefully
predicted.