Problems in Tech Summary

Overall in this class I have learned a lot about new technological concepts and about working effectively as a team. I learned how to better divide work up among other people, allowing us to get a task done much quicker and more well done. I am also glad to have had Austin as a partner, as we work very well as a team and bring different ideas to the class.

I learned a lot about different forces, such as drag and lift with the aerodynamics project, and also how to get the most potential energy into usable kinetic energy with our catapult. I am now much more confident with many more power tools, and can create better projects. I am glad to have taken this class, as I have learned a lot.

Storm the Castle Project

For our second project, we were given the task of creating a catapult, ballista, tribuchet or other siege engine that had to be able to launch marshmallows 15-25 ft away. The machine had to be consistent and must be able to fit on a 8.5 x 11 sheet of paper.

The concepts we learned about for this project were mainly regarding energy and energy transfer from potential to kinetic like when the rubber band compresses and decompresses.

The learning goals for this project were to be able to build a machine that can accurately and consistently launch a marshmallow while being confined to a 8.5 x 11 in space for building.

For our design we started with a simple catapult with a 15 in lever situated between two pieces of wood on a dowel rod. Above the lever is another piece of wood where rubber bands connect to the arm. This allowed us to get a lot more power from the catapult. On the bottom a locking mechanism was added so it would not fire unless we meant it to.

Our catapult was able to shoot accurately up to 25 ft away. The catapult also held up very well through every test and was able to launch the marshmallow into a bucket every 1 out of 3 attempts.

We had to make extensive redesigns to our project to make it launch far. Originally it would only launch 8 feet. We had to change where the rubber bands were mounted to the base, and this gave us a lot of improvement. 

For this project we had no lack of resources. First, we have a lot of time to work on this project, over 2 weeks to build and perfect. We also had access to good tools including band saws, drill presses and jigsaws.

The biggest challenge was finding out how to increase our range as much as possible. We found out the maximum trajectory comes from launching the projectile at a 45 degree angle.

I learned that redesign is extremely important. For this catapult our redesign increased our final range by over 400%, going from 8 ft all the way to 25 ft.

For this project we were given the task of building a CO2 powered car, and making it run a 20 yard track as fast as possible. The car could take on just about any design we wanted, just as long as the total weight was above 5 ounces when finished.

Before we began building, we first had to understand the basic concepts of aerodynamics such as drag and lift forces. Drag refers to forces acting opposite to the relative movement of an object, and lift being a force pushing up on the object.

The main learning goal for this project was to reduce drag by as much as possible, therefore making the vehicle travel 20 yards as fast as possible.

For our design, we started with a simple triangular shape. We then began to cut down the piece to reduce weight, and make it more aerodynamic. We also sanded down the edges to allow for smoother airflow over the car.

Overall our car performed very well.  Out of all the other groups our car was the second fastest to 20 yards.

The only redesign we had to  make for this project was making it more lightweight. The original design was a bit to heavy, and we simply cut it down a bit and sanded off the edges a bit more to get as close to the target 5 ounces as possible.

For this project we had no lack of resources. First, we have a lot of time to work on this project, over 2 weeks to build and perfect. We also had access to good tools including band saws, drill presses and jigsaws.

The biggest challenge was really just finding out how to make the car as fast as possible. Getting as close to the target weight as we could while making it as aerodynamic as possible.

From this project I learned a lot about aerodynamics and the forces that act upon a moving object. I also learned how making small changed can have a huge impact on the performance of aerodynamics.