T R E B U C H E T

T R E B U C H E T

A Semester-Long Engineering Project

By: ANDREW ALTON

Why did I do this?

Pent up rageDestroying People/ThingsWeapons at schoolNothing better to do

on Mondays and Wednesdays anymore

RESEARCH

Only few internet sites w/ worthwhile info“How-To” Websites:

www.trebuchet.com “A Treb” computer variables data

Data-Variables

Cool Simulation

The BUILDEvery Monday and Wednesday

around 6-9 PMTools from home THE HOME DEPOTMr. Dohm reimburses me for the $200

I spent on materials

The Start

Used old trebuchet(s) from last semesterUsed about 40% old materials, 60% new materialsBasic plan: Make the old trebuchet into one that works very well and launches a projectile

Components of a Trebuchet

Long, very strong “Arm”Axles must not bendShould have wheelsCounterweight: heavy & compactSling launches projectile fartherTrigger safety first!

The ARM

Triple 2X4 Triple 2X4 constructionconstruction

Holes must be bored perfectly level, so arm is plumb.

Axles Cotter Pins Hold Arm from moving horizontally

More cotter pins so axle doesn’t come off supports

Screwing it together is easier

Axle Grease

The Counterweight

First tried concreteThen looked all around for weightsHOME-DEPOT paving bricks:

Cheap & real HEAVY30 bricks X 5 lbs. ea.

=150 lbs.!!

S l i n G

No pre-made slings; made it myselfSewing strap-strongerOne end of sling string is attached to trebuchet, the other is attached to a metal ring- slips off

TriggerLaunch trebuchet from a safe distanceHeavy duty construction meant a safe launchAbout 100 lbs. of force

1. Slip metal ring attached to the arm over the trigger rod.

2. Stick a screwdriver shaft through eyebolts

3. Pull screwdriver out with an attached string

Final ProductArm is strong and efficient

Outriggers keep trebuchet from wobbling

Swiveling wheels allow easier transportation

Center channel guides projectile

Testing

First couple tests- trebuchet fell completely apartNext tests with bricks- bricks fell out of counterweight boxAdded blue tarp on counterweight box to keep bricks in Tried different projectiles: Water Balloons, Concrete Ball, Steel Shot-Put, Then a Large Rock.

Movie Of Trebuchet Trial

Second Movie of Testing

MY FUTURE TREBUCHET

Counterweight:2 X 55 gal. Drums w/

Water = 990 lbs.Perfect for launching Underclassmen, preferably Froshes!Beware!…..