All About Catapults

Welcome

Welcome to our Blog! Here, you can learn many things about catapults. Look around and be amazed!

Leonardo Da Vinci invented several catapults, but in our experiment we tested the most commonly known one. The catapult is powered by a large wooden leaf spring, which serves as an accumulator. Though no record of this catapult being built during Leonardo's lifetime exist, lifesize replicas have been constructed by contemporary enthusiasts.

The Da Vinci model is loaded by turning a winding mechanism that turns a drum. That drum is connected to the catapult armature and pulls on the springs connected to the bow of the leaf spring, where tension builds up. When the winding mechanism is disengaged from the drum, the tension on the bowstrings is released, causing them to pull back to their original placement, and pulling the gear and armature with them.

The Da Vinci Model was one of Leonardo Da Vinci's various inventions in his notebook that were never made during his lifetime. Da Vinci designed his catapult to be able to launch projectiles over great distances with great speed. But it did not have a usual trajectory such as that of the trebuchet and mangonel. The Da Vinci Model was not made to launch projectiles low and fast, or high and powerful. Because it was loaded by winding the crank, one person can launch the Da Vinci Model alone.

Conclusion

There is no catapult that is the best at everything. Each catapult has its own advantages and disadvantages. Hundreds of years ago, generals chose which catapult to use based on their current situation.
To tear down a stone wall of a castle, the mangonel would be the most suitable choice. To haul sick cows and burning wood inside of a castle, the trebuchet would be the best choice.
Because there were so many situations in which catapults were deployed, engineers built many different varieties of catapults to use. Catapults played a vital role in sieges and battles because they could bring down structures and cause havoc in the opposing army. For this reason, almost every culture developed some kind of a catapult over the years.
Eventually, cannons replaced catapults, but their long-lasting legacy will never fade away...

Projectile Analysis

It is impossible for us to pick the best projectile in terms of the amount of damage it caused, because you have to factor in the speed of the projectile, the mass, the density (hardness), surface area, force it hits the target, and etc. We simply had no equipment to measure this.

However, it is quite simple just to measure the distance and the height each projectile flew.

The lightest object, the plastic hollow ball, flew the farthest. Newton's third law of motion was thus proven, since the lightest object flew the farthest and the heaviest object (the large marble) flew the least when the same force was applied to them. For height, it was similar between the plastic hollow ball, small marble, and die.

But it must be noted that these ranges of each projectile isn't everything, because a ping pong ball that flies 5,000 light-years through space isn't going to do that much damage unless the velocity is way over 1,000 mph.

Catapult Analysis

The mangonel established itself as the catapult with the most range, as it surpassed both the Da Vinci model and the trebuchet when it came to distance. The Da Vinci model did not do too much worse, it still performed considerably better than the trebuchet. The trebuchet did come in last, for it sacrificed distance for height. When it comes to height, the trebuchet did show the highest reaching trajectory, with the Da Vinci model and the mangonel not performing nearly as well. As for launching force, the mangonel did surprisingly worse than its counterparts, who had similar launching forces, with the Da Vinci model a little bit ahead of the trebuchet. The consistencies of the mangonel and Da Vinci model were pretty similar, but the trebuchet's consistency in distance, height, and launching force was considerably worse. The mangonel did outperform the Da Vinci model by a bit, making it the most consistent catapult. Rather than looking at the individual performance of each catapult for each test, we looked at the overall performance of each catapult, and decided that the trebuchet's performance in the average distance, height, and launching force earned the top spot.

Testing Out the Models-2 (Directions and Procedures)

Our experiment consists of two parts: a) the testing of the catapults and b) the testing of the projectiles. After testing each catapult's performance, we tested different projectiles on the Trebuchet model.
To test the catapults, we used a small standard, cheap, made-in-china marble.

The Experiment

Materials: Scale models of the mangonel, trebuchet, and Da Vinci catapults, small hollow plastic ball, small marble, large marble bouncy ball, cubic die, scale, spring scale, ruler, tape measure, and calculator.

Procedure(for both parts of the experiment):

Determine the volumes of the different projectiles by measuring their diameter and using the following equation: For the die, use LxWxH=V. Record your data in in cm3 in Data Table A (Projectile Volume).

Determine the masses of the different projectiles by placing them on the scale and recording their mass to the nearest tenth in grams in Data Table B (Projectile Mass).

Line up all three catapults at one line. Fire them all using the small marble. Using the tape measure, measure the distance the projectile travels before hitting the ground. Do this three times. Calculate the average of the three times. Record all this data in Data Table C (Catapult Data).

Keeping the catapults in the same position, fire them all with the small marble, using the tape measure to measure the height of the highest point of the projectile's trajectory. Do this three times. Then calculate the average projectile height for each catapult. Record all data in Data Table C (Catapult Data).

Fire each catapult, but while restraining the arm or beam using the spring scale. Do this three times, then calculate the average for each catapult. This is the launching Force. Record all data in newtons in Data Table C (Catapult Data).

Calculate the range for each set of trials for each catapult from each of the trials, and that is the Consistency/Accuracy of each catapult variable. Record this data in Data Table C (Catapult Data)

After determining the best catapult, use that catapult to measure the distance of the different projectiles. Do this three times and calculate the average. Record all data in Data Table D (Projectile Data).

Record this data in Data Table D (Projectile Data).

Testing Out the Models-1

After we researched about different types of catapult models, we wanted to test them. So we bought three kits of catapults: the trebuchet model, the mangonel model, and the Da Vinci model.
We had a question: Which catapult will have the best performance considering the distance and height that projectiles are thrown, the consistency of the catapults, and the launching force of each catapult? Which Projectile will have the best performance considering the same variables?
After coming up with the question,we hypothesized that the trebuchet would have the greatest projectile height and accuracy/consistency, the mangonel would have the greatest distance, and the Da Vinci model would have the greatest potential energy.
I will talk about the detailed procedures of our experiment in our next post, Testing Out the Models-2.

The Da Vinci Model

The Da Vinci Model was one of many inventions sketched by Leonardo Da Vinci in his various notebooks. A life-size model of the Model was not constructed until today, by contempory enthusiasts with the necessary materials. Da Vinci designed his catapult to be able to launch projectiles over great distances with great speed. But it did not have a usual trajectory such as that of the trebuchet and mangonel. The Da Vinci Model was not made to launch projectiles low and fast, or high and powerful. Because it was loaded by winding the crank, one person can launch the Da Vinci Model alone.

Welcome

Tuesday, June 5, 2012