Egg Joust feat. Max by Greenlee, Martinez and Nobal

Jake Greenlee, Tom Nobal, Carlos Martinez

Period 5

Mr. Yav

Vehicle name: Max (named after how it looks like a mad max car)

Table of Contents

Introduction

Design

Materials

Construction Procedure

Operation of Mousetrap Car

Results

Conclusion/Improvements

Introduction

          The purpose of the mousetrap car project is to display knowledge of basic physics principles such as how mass and force affect the speed of the car, how longer and shorter pulley arms affect the distance and speed, and how the heavier the car is the longer it will take to stop. Our first thoughts about this project is that we wanted to rely on a short burst of speed to get us going, and then gravity would take us down the ramp. However we were not sure whether or not the short burst of speed would be powerful enough to get it moving. We also were unsure how powerful the mousetraps were so we were unsure whether going for a fully speed based car would be the best idea. We also wanted to be able to protect our egg and attack the opponent's egg. 

Design 

          When we were brainstorming we had many great ideas.  But some of them ended up hindering us instead of helping so we decided to scrap those ideas. We decided that we wanted to gear our car. Our thoughts at the time were that it would dramatically increase our speed so we would have more force when we hit the opponent's car. As seen below, the basic premise behind gearing is that a big gear which is the one being powers turns a smaller gear that spins faster due to shorter turns.

We wanted to gear it as seen above. It would be big gear to small gear, and then back to big gear then to small gear. When we tried this it did not work. Then we tried it with only 1 big gear to small gear. That one worked but it was very slow. Here is one of our prototypes below.

We ended up scrapping this idea and not gearing. We also wanted a mechanism that would be attached to the front of the car and would flip the opponent's car. This ended up being impractical because our classmates' cars were heavier than we expected and wouldn't be able to be flipped easily. 

We also wanted a defense mechanism that would flip up and cover the egg after the car started moving (Mr. Yav approved idea). This ended up being way too complex so we scrapped that as well. 

The one thing that did work was our idea to raise the egg. This would be easy and it would protect the egg from jousting sticks lower to the ground. 

Our final design ended up being this

We added foam in the front to lessen the force exerted on us by other cars and like we said before we ended up not gearing and directly powered the axle with wheels. We also raised our egg platform and added sticks on the bottom as anti tipping mechanisms.

Materials

Plywood- Free- estimated cost around $10

Wooden dowels- Free- estimated cost around $4

Foam- $2

Duct tape- Free- estimated cost around $3

Lego wheels and axles- Free- estimated cost around $10

Mousetrap- $4

Hot glue- Free- estimated around $5

Pipe cleaners- Free- estimated cost around $3

Total Cost: $6                

Total Estimate Cost: $41 

Construction Procedure

Tom I'm trusting you can do this one. (lies)

The construction procedure does not include procedures used to build prototypes.

Acceleration:

1. Acquire all materials

2. Cut the plywood roughly into this shape. This will be the chassis of the car. Make sure that there is space for the mousetrap and some extra space lengthwise. Make sure that there is enough space in between the prongs for the wheel. 

3. Cut two plywood parts in this shape:

4. Glue on the two plywood pieces to the frame so that they stick out the opposite end of the prongs. 5. They need to be far enough apart to fit the front tire without it hitting the edges. 

6. Cut the lego parts so that there are 4 lego bearings. Be careful to cut well around the hole you are planning to use, otherwise the hole will be deformed. 

7. Glue the lego bearings onto the front tire mount so that there will be space for the wheel. The lego bearings need to be accurately placed apart from each other so that an axle can be spun without difficulty. 

8. Repeat on the other side so that there are bearings on both sides. 

9. Attach the front wheel by putting the axle on with the necessary spacing.

10. For the back, make sure that the axle is designed like below and attach it and the wheels.

11. Attach the mousetrap to the top of the car with duct tape and hot glue. The activator should be pointed towards the front of the car.

12. Attach a dowel to the mousetrap’s snapper so that it reaches directly over the axle using hot glue and duct tape. 

13. Attach a wooden dowel to the end of the stick. There should be about 2 feet of string. Attach the other end of the string to the center of the axle in the back wheel through the hole. 

14. For the egg holder, fashion the pipe cleaners into a basket.

15. Then support the egg in the air using the dowels as shown. The basket should be high enough to clear the action of the mousetrap without being hit. The car should look like this:

Joust

1. Acquire about 100 grams of weight. In this instance, we used coins. Attach it to the front of the car in between the mousetrap and the front wheel. 

2. Using the pipe cleaners and foam, build towards the front of the car outwards to create a crumple space. 

3. Build a second crumple space on the basket towards the front .

4. Attach dowel holders on the frame of basket holder. They should be tight enough to hold the dowels, but the dowels should still be able to move. The car should look somewhat like this at this point: 

5. Attach a dowel across the bottom of the car perpendicular to its motion. 

Operation of Mousetrap Car

The power of the project, as previously noted on the design section, originates with the mouse trap being set off. The spring mechanism embedded in the mouse trap creates power which, through the string, is channeled to the wheels. This happens by means of the mousetrap pulling on the string which is wound around the axle attached to the wheels. The wheels, which are carefully positioned so that the bearings create as little friction as possible, spin quickly and the car moves forward at a high speed. There is also additional work on the car as their is potential energy due to the height. As it moves down the ramp, where gravity adds acceleration, that potential energy turns into kinetic energy. That helps add speed to the vehicle and ramming power that would hit the other car. Hopefully there is little friction to increase speed. 

To successfully compete with other mousetrap cars, several other design operations had to be in place. As a defensive tool, a wooden stick was applied at the bottom of the project to prevent it from tipping over. Keeping the egg safe is top priority. There was tons of crumple space added to the front of the car to lighten the impact. This would operate by, when coming to contact, compressing in front of the car, thus taken away energy from the impact. This is similar to the crumple space of a real life car which creates a safety feature for the passenger. 

As an attack design, two mounted sticks were added and kept in place with bendable pipe cleaners. The lack of grip on the two sticks allowed them to be moved forwards or back depending on the situation. This also means that the basket would not encounter any significant force to it in the event of an impact, for the sticks would hopefully impact their car. With these additions, there is a secure place for victory in competing with other mousetrap cars. 

Results

Our car did remarkably well, getting second place in the acceleration portion with a 1.02 second time to traverse 1.5 meters. We also did well in the jousting portion, getting 2nd place. 

Our acceleration was 2.89 m/s/s

G: velocity initial (Vi) = 0m/s, time (t) = 1.02 s, distance (x) = 1.5 m

U: a (acceleration

E: x= Vi*t + ½ a t^2 

S: 1.5m = 0 * 1.02s + ½ a (1.02)^2

S: a = 2.89 m/s/s

The egg did crack during our last joust, it fell out of the car and cracked upon impact with the ground. 

Conclusion/Improvements

Our mousetrap car was a massive success in competing with other designs, as we got an overall second place and were first among those who never lost. The intricate and thoughtful designs payed off in the end and led to a close victory. Our speed was also surprisingly good, especially with all the extra weight. In fact, our design reached second in class speed with 1.04 seconds to get across the track. 

In conclusion, our success leads us to believe that our design was done exceptionally well. Still, there should be improvements added. One thing that could have been improved to achieve full victory is a greater attack mechanism. The majority of our car was constructed to remain cautionary and to keep our egg from falling off. The addition of an attack tool might have allowed us to win. This could be adding more weight to increase the force of the mousetrap car or even an extending arm that would get rid of the opponent’s egg would be effective. That would have geared our path towards victory.

Design Report

1/28/16

Physics

Mr. Yav

Jake Greenlee, Tom Nobal, Carlos Martinez

Summary

In this project we are building a mousetrap powered car that will accelerate very fast. The car will also hold and egg. The mousetrap car will be put head to head against other cars. The goal will be to destroy the other cars egg. While keeping our egg safe. We plan on gearing our car for more speed. We also may later add some defenses that pop up and weaponry to the car. 

Table of Contents

Summary

Design Problem and objectives 

Design documentation

Test Plans

Bill of materials

Task Chart

Safety and ethical consideration

References 

Design Problem and objectives 

The objective is to create a mousetrap car that travels fast and maintains its speed for a short period of time. Our secondary objective is to knock the opponent's egg out of their car. Our goal is to make a very powerful car that will provide sufficient defense and will possibly have an attack mechanism. In order to create a more powerful drive base we will need to keep in mind the length of our pulley arm. Because the longer it is the more weaker it is and the shorter it is the more power it will have. But the disadvantage with shorter arms is less distance. That's why we decide on a shorter arm but we are going to gear it for extra speed. We hope that the extra speed help level out the disadvantage that comes with have a shorter pulley arm. One problem that we could have with this design though is not having enough torque to spin the gears. We also plan to add a defensive wall that will pop out a specific amount of time after moving. As to how it will activate we still are thinking on that. As well as defensive measures we might also add an offensive measure. This offensive measure will be a mousetrap that will swing up after coming in contact with another car. This will in theory flip the opponent on their back making their egg fall. We believe that if we perfect all of these thing we will have the best mousetrap car in the lab, because it will be fast, it will knock the opponent's egg out, and it will have a defensive measure to defend the egg.

Design Documentation

Mouse trap car design : 

Drivebase: 

To run the car so that it will accelerate as fast as possible, we determined that a gear box would work the best to maximize the use of the single mousetrap. The gear system will be geared for speed, with a large gear turning a small gear.

The initial gear will be turned by the pulling arm mounted on the mouse trap. Based on information from the slideshow provided by Mr. Yav, as well as previous experience, a short pulling arm will give us the torque needed to turn the gear system. Work is being put into the gearbox, which then turns the wheels. To make sure the system is secure, lego parts will be used here, but the use of legos will be limited in the rest of the project. Wide short rubber wheels will be used for maximum traction and speed. For the acceleration test, the car will be light enough so that it can accelerate quickly, but for the joust, the car will be weighted down enough to resist ramming other vehicles. 

Offensive measures:

     For the offensive measures, my group and I decided quite a couple of different solutions to combat this issue. The first and most prominent includes another mousetrap being set off by the opponent’s car. The idea is to have the second mousetrap at the front of the car as to be set off at the time of impact. Hopefully, if all goes well, the arm of the mouse trap will hook up under the enemy car and flip it over. The second will be the inclusion of more mass added to our vehicle. Because of the principle, F = ma, our inclusion of more mass would add a greater force to impact the other car with.

Defensive Measure: 

We decided that for a defensive measure we would add a barrier that pops up after starting to move. This will be powered by a mousetrap that will be triggered by the mousetrap that powers the drive base. The idea behind the activation is that the first mousetrap will have some sort of stick connected to it that when the mouse trap reaches a certain point it will activate the defensive mousetrap. One problem we have to keep in mind is the barrier hitting the egg. The barrier needs to be strong in order to defend against attacks. But it also needs to be soft in order to not damage the egg. Our heavy weight will help with defense because if we are heavier than our opponent we will take less time to stop. Because it takes less time to stop our car, the opponent will essentially act like a crumple zone.

Cost Analysis:

The total cost that will be in regards to our project will be an estimated $45

Human Factors:

     If Applied with care, our vehicle should not be of any harm to any persons, however, if one were to carelessly apply pressure to any of the mouse traps, it is expected that they may suffer in some way. (Not clear on what the human factors entails)

Test Plans

Drivebase testing:

down hill launch

ability to turn wheels

on level ground from a standing start

Gears don't lock

With weight, car must be able to move

Defensive testing:

making sure hard stop works

make sure when defensive mousetrap is activated, the egg is covered and not damaged

activates quickly so that the egg is protected

Offensive Testing 

Flips after impact 

Activates

Attack does not result in damaging the car or egg

Testing on a smaller car for effectiveness. 

Drivebase scenarios:

There could be not enough torque to move the gearing

Wheel spins too quickly and skids, causing us to lose power

Gearing system fails, gears not strong enough.

Different brands of mousetraps 

Defensive system scenarios:

mouse trap stopped fails, crushes egg

cover is not sufficient to protect mouse

may not activate

Offensive system scenarios:

Doesn’t activate on contact with other car

Doesn’t catch under other car, and fails to apply a meaningful affect.

False trigger, activates early 

Bill of materials

3 mousetraps, one powering the car, the other 2 for offensive and defensive measures 6$

lego parts (gears + wheels + supporting frames) ~$25 (taken from existing stores)

pipe cleaners ~$2

hot glue gun ~ $10

tape ~ $1

pencil/ sturdy stick ~ $0.50

small cardboard box ~ $0.50

Task Chart

-Finish design review- All members - 1/28/16

- Prototype gearbox- Tom Nobal - 1/28/16

- Testing gearbox - Tom Nobal - 1/28/16

- Test different gearing + puller length - Jake + Tom - 1/29/16

- Defensive measures prototypes - Jake - 1/31/16

- Offensive measures  prototypes - Carlos - 1/31/16

- Getting mouse traps - 1/31/16

- Getting plywood- Jake - 1/31/16

- Assorted Materials - Everybody - 1/31/16

-Testing speed runs - Everybody -2/4/16

-Day of Acceleration competition

- Modify car for joust - Everybody - 2/5/16

- Testing offense/ defense - Everybody - 2/11/16

- Day of Joust 2/12/16

-  blogger - Carlos - 2/22/16

- design report - everybody - 2/22/16

Safety and ethical consideration

The car is not meant to hurt human beings, it is only meant to damage/destroy other eggs, while protecting a egg at the same time. None of the spring loaded offensive or defensive measures will be able to severely hurt a human unless they do something unintelligent. 

When designing the car, efforts will be taken to avoid injuring those that will be using the car or watching it. 

References

Powerpoint provided by Mr. Yav

Experience provided by previous mousetrap car projects

Experience from robotics

Experience from theater tech

Tom Nobal's Rocket Launch

Introduction

For a physics experiment, we had to design and build a bottle rocket that would be able to carry an egg as its payload, with the requirement that the payload separates from the rocket and the egg survives the journey. The rocket also needed to reach a minimum height. 

Materials

The rocket had all of the components required to insure that the rocket launched and the egg placed inside the rocket would survive. Prices provided are rounded. The rocket would cost 

-2 2 Liter bottles at  $1.50 each

-Duct Tape $5 

-Posterboard $5

-Plastic Trash Bag $29 for 1000, so cost of $0.029 per unit

-String $5

-Foam $18.5 for 225'x12''x1/16'

-plastic bag $10 for 500 units, $0.02 per unit

-box knife $13

-Marker

-ruler

Procedure

1. Empty the two 2 liter bottles of soda by either drinking it or emptying it down the drain. Mark one as the fuel cell and do not make any cuts to this one. For the other one, mark the area of the bottle near the bottom before it begins to curve inwards to create the bottom. Also mark an area about halfway from the top of the bottle.

2. Decide how you want to create fins. Draw out the fin shape with a ruler, then cut it out. For this particular rocket, cut them out in the shape of a right triangle where one side is significantly longer than the other. Cut out 4 fins that are the same size and shape.

3. Cover the fins with duct tape and take care to remove any wrinkles. This improves air resistance as well as waterproofs the fins.

4. Attach the fins to the fuel cell so that the long side "points" upwards, which is towards the bottom of the bottle. They should be evenly placed around the bottle just before the bottle curves downwards towards the opening. Attach them with duct tape, taking care to make sure that the fins are firmly secured and the duct tape is flush with the rocket

5. On the second bottle, cut along the marks. In the section of cut bottle containing the original opening of the bottle, cut 4 slits 1-1.5 inches into the bottom of the cut portion. This section is the nose cone

6. Attach the section of plastic that is a ring to the top of the fuel cell using duct tape

7. Take one of the large garbage bags and expand it fully. 

8. Attach 4 pieces of string that are of equal length to the garbage bags at 4 points that are equal distances from each other. Use duct tape, but attach the string to the duct tape as shown below. This method makes sure the string will not slip.

9. Attach the strings to the rocket in 4 points that are equal distances from each other to the bottom of the nose cone below the slits using the same method of attaching string to the duct tape. 

10. Place foam inside the nosecone around it to create a hollow on the inside. Use scraps of foam and place in the center for extra padding. The foam should not interfere with the strings. 

11. Take an egg and place it in a plastic bag. In the event of a tragedy and the egg breaks, the rocket will not get dirty. Remove as much air as possible from the bag.

12. Place the egg and plastic bag inside the hollow in the nose cone.

13. Place the bottom of bottle 2 inside the nose cone and duct tape inside so that the egg and foam do not come out. The piece may need to be trimmed. 

14. To assemble the rocket, fold up the parachute and string and place inside the nosecone. It is fine if it doesn't fit, the rest of the parachute will fit inside the ring on the blast chamber. The nose cone will fit inside this ring and be seated. When the rocket is turned on its side, the two parts should separate with some ease. 

Launch Configuration

Results

Unfortunately due to the circumstances, a comparison to other rockets is unavailable (sickness). The weather was a bit windy which may have caused the rocket to start leaning to one side. The rocket failed in one major section, height. The nosecone and fuel cell separated early, meaning that the rocket didn't reach it's maximum potential height. The rocket succeeded in another area though. Even with an early separation, the parachute deployed and the egg survived.

 Some calculations reveal the height to be only 13.8 meters since the parachute deployed early. 

Based on this, the velocity was 16.44 m/s.

At the moment of launch, there were 2 forces acting on the rocket, F (applied) and F (gravity).  (air resistance negligible)

At the highest point, there was one force acting upon the rocket, F (gravity). (air resistance negligible)

Conclusion

The rocket performed well but had some flaws. In manufacturing the fins, more care could have been taken as to remove wrinkles from the fins. In addition, the nose cone separated early, which was due to the nose cone having insufficient support that kept it on the rocket. A possible solution would be to increase the length of the stopgap piece to increase how much area was used to secure the nosecone. Another possible reason for the nosecone falling off early would be lack of aerodynamics since there was no proper nose cone that would allow the rocket to cut through the air. In addition, the wind may have played a factor by pushing the nosecone off of its seating. The parachute deployed well and slowed the rocket's descent, allowing for the egg to survive. In addition, the padding was sufficient enough to withstand the forces of impact along the ground and any rolling forces caused by the nosecone rolling and bouncing along the ground after landing. In the future, I might use a bigger parachute, or several parachutes. I might use a longer launch tube with bigger fins in order to increase stability. A logical and technological step up from this rocket would be a 2 stage rocket, with 3 bottles used for the first stage in order to get the rocket up to a certain height and another bottle that would launch for the second stage in order to reach even greater heights. 

Test Post

Today it rained. This is surprising.