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(Young Engineers by The Decade Group)

(Table of contents)

Introduction4What’s Expected5Work Procedures6Part Names9Basic Lesson Order16Spring-Powered Race Car16Pirate Ship18Conveyor Belt20Power Plant22Manual Electric Beater24Windmill27The Lever Principle30Motorcycle35Amusement Park Carousel – Chair-o-Planes - Manual36Laundry Machine38Flywheel – The crazy clown (A Ride at Euro Disney)41Towing and Towed Vehicle44Crane46Vehicle from the 20's48Winch – Rescue Jeep49Tunnel Boring Machine or Electrical Drill51Lifting using Pulleys53Balloon Car and Rocket Launching56Plough58Railroad Barrier59Amusement Park Motored Merry-go-Round – "Chair-o-Plane"60Industrial Mixer – Preparing a cake61Applauding / Flying Man63Light Aircraft - Cessna66Sand Buggy67Wind and Water Turbine70Flipping Car72Robot Rabbit77Elevator79Cable Car80Street Sweeper (The simple version)83Human Robot85Catapult88Rescue Helicopter89Last Meeting – Handing out the Diplomas91Life Belt – Backup Lessons:92Spinning Top Launcher92Drum Machine / Metronome (Simple Version)94Improvised Race Car95Ferris Wheel96Amusement Park Carousel II99Elastic Car100

Introduction

The year 2011 is a year of accelerated expansion at “The Decade Group”. This expansion rate is expected to continue through the next couple of years as well. We see the release of this booklet as part of the company’s expansion effort and as part of improving the means of fostering the instructor in such a way that will ease his training and advancement.

We define our instructors as irreplaceable assets, and from this the company aims to give optimal responses to the instructor’s needs in particular, and the different needs in general.

This booklet provides general information about the young engineers’ class – extreme Lego, about “The Decade Group” company and about the day to day conduct.

In this booklet, it is detailed among other things, the work practices and the different lessons plan with the proper methodology of giving them. This booklet is here to answer the needs of the instructor needed in passing on the curriculum in the best possible way, and to increase the efficiency of passing the information form the company to its instructors.

For those starting with us, or those continuing their work with the company, to look thoroughly through this booklet, and read it with the proper consideration before the beginning of each lesson. Also, do not hesitate to forward any question that arises to your superiors.

This booklet is updated as of September 2011. The company might change details included in the lesson plans and work procedures, all this with giving proper notification and proper training in accordance to these changes.

As stated in the work procedures, it is forbidden to use this booklet during the lesson, so the lesson isn’t recited from it. Also, it is forbidden to give or copy all or any part of this booklet to anyone.

In Conclusion,

Welcome to the “Decade” Family

Greeting you – The entire instructor team

A joyful and successful year

What’s Expected

Honorable Instructor,

Welcome to “The Decade Group” family.

We have given ourselves the goal to develop and provide creative educational solutions to all of Israel’s children from all religions, colors and genders and from all areas, from the big cities to the peripheries.

We see you as our sole representative in front of those children in those areas, and expect you to perform a number of actions while being as sensitive as possible to the participating children:

1. A No Tardiness policy: Arriving on time to class is of utmost importance to the success of the class. On the first days of you working with, please be punctual and leave your home early in order to arrive on time to your scheduled lesson or activity.

2. Forming a personal relationship with the class coordinator: With a goal to take your place in the community where you are assigned, you are to establish and nurture a personal relationship with the class coordinator.

3. Forming a personal relationship with the parents: The parents are the best publicists of our classes. There is no substitute to good word-of-mouth marketing. Therefore, you are to establish a good relationship with the parents.

4. Building anticipation – customer retention: Your role is not solely educational. In addition, your role is to develop anticipation for the rest of the lessons and the rest of the experiences. Therefore, you are to tell the children with enthusiasm of the other models we’ll be building during the rest of the year.

5. Usage of the company website: Encourage the parents and children to both surf our website. The site includes movies, pictures and message about birthdays of the children who signed up through the website.

6. Recommendation – Star Pupil of the Week: Every week a different child should be noted for his exceptional work. Be sure to keep a proper rotation so that everyone is picked. Where applicable and in coordination with the lesson coordinator, post a picture of the child on the center’s message board.

7. Remember the main goal: You are to make sure the child leaves with a glow in their eyes and a wide smile, and tells his friends and parents with enthusiasm of the experiences he has in class!

Know that the future budget of The Decade Group in the field of development and current operations depends directly on your success as an instructor. Make sure to enlist a large number of children, and keep them for the benefit of his education, joy, for the satisfaction from your work and wage, and for the justification of you being an instructor with the company.

Wishing you the best of luck,

The Decade Group

Work Procedures

General Guidelines:

1. Take attendance at the beginning of each lesson.

2. Be sure to dress appropriately.

3. Keep the Lego with you at all times.

4. Be sure to collect all pieces from the floor at the completion of each lesson.

5. Before every lesson the instructor is to scan through the lesson plan, build the model, and after study the plan carefully.

6. The instructor booklet and its contents are confidential (as all lesson content), therefore it is forbidden to make it available to the masses, and hence the instructor must learn the lesson plan by heart and not take it with him to different educational centers.

7. You must promote the class every two lessons. Therefore the instructor must be familiarized with all the models built during the year.

8. It is highly recommended to photograph the children at the end of every lesson. The photographed models will be uploaded to the website once a month. Have the parents sign a document permitting us to us their children’s photos, using the format provided by us.

Sticking to timetables:

1. You must be ready to start the lesson at the scheduled time.

2. You must have your break at a place in close proximity to the center where your next lesson is and not where you just finished. Remember, as the day progresses road traffic increases.

3. Being precise with the schedule is of utmost importance, every delay can potentially cause discrepancies in the schedule and can harm the companies reputation.

Proper conduct in front of the children:

1. Make sure during every lesson that each child finishes his model.

2. Before the start of the year every instructor should go over punctuation rules and block letters.

3. The children should come and show the instructor each and every stage. The instructor doesn’t walk around the class, except for in special cases or a small number of children to take care of is left.

4. No smoking permitted in front of the children.

5. No talking on cellular phones during the lesson.

6. The use of profanity is absolutely forbidden!

7. It is strictly forbidden to dismiss the children before the scheduled end of the lesson.

8. If the lesson ends and there is no security guard, do not leave the child before his parents arrive to pick him up. If the lesson coordinator or any other acceptable authority figure is present, pass the child to his care.

9. It is strictly forbidden to remove disturbing children from the classroom.

10. Be alert and pay attention to the children’s behavior.

11. At the start of each lesson pick one child to be on “sweets duty” (every week one child be in charge to supply the class with minimum cost sweets) and make a note on the attendance sheet.

12. Print a note for the parents telling them about the “sweets duty” appointment for the next lesson – this is to give validity to the importance of the assignment to the parents.

13. Hand out the sweets to all the children together. A child who finished organizing his kit early to assist the instructor with clearing the classroom or with assisting the other children.

14. Encourage the children to surf the class’s website at their personal leisure.

In case of a disorder in discipline:

1. Have a talk with the child in the class and make him aware of the rules.

2. If to no avail, consult with the superiors or authorities at the institute about what steps should be taken next (phone call to the parents, suspension, dismissal, etc.)

3. Do not hesitate to call the parents if needed.

4. After taking the necessary measures, inform us of the steps taken so you could be provided with tools to handle future occurrences.

Proper conduct with the school or institute:

Building, nurturing and maintaining a personal relationship with the institute you are working with is crucial to the success of the yearly activities, therefore:

1. Keep the classroom neat and tidy.

2. Preserve the classroom’s equipment.

3. At schools – Life the chairs at the end of each meeting.

4. Act politely to anyone who concerns you, especially the cleaning and maintenance staff.

5. Make sure with your superiors that you have all the necessary phone numbers of the class managers at your place of work.

6. Past years have raised a phenomenon as a result of successful marketing- the classrooms are filled to zero vacancy. This caused, not once, the failure of the class and the need to start over due to failure to acclimate on both the side of the instructor and the pupil. Consequently, there is the option to sign up for the trial lesson on the class’s website. This was done to limit the number of participants in the trial lesson to no more than 25 children. Encourage the class managers to point the parents towards the online registration.

7. As you arrive at the first lesson use the report received from your superiors, stating the names of the children whose places are reserved and those in the waiting list. You are to accept the registered children first and fill the 25 head count with those on the waiting list. For your success – remember that a number higher than 25 in a lesson diminishes the quality of the lesson, and based on experience might even cause it’s failure.

Proper conduct with the parents:

1. Remember the parent is the one paying. Therefore, listen to his instructions.

2. Suggest to the parents to visit the class, and even participate.

3. Notify the parent his child appears on the website, and there he can view his different projects.

Proper conduct with the company:

1. At the end of each month, fill a monthly report based on the model you receive at the beginning of the year.

2. At the end of the year return all the supplies arranged and organized the way you received it.

Changes and cancellations:

1. Under extraordinary circumstances, after consulting with the supervisors, it is possible to changes the lesson plan, its duration and its scheduled date.

2. A cancelled lesson must be rescheduled.

3. Use extreme judgment when it comes to cancelling a lesson, and refrain ffrom doing it close to its original date.

Safety while using the equipment:

1. Usage of the kit is not allowed to children under the age of 5.

2. Choking hazard! Do not put the different parts in your mouth.

3. While building Lego launchers – Keep a safe distance between the launcher and the face.

4. Rubber band launchers – It is forbidden to have the lesson without the proper eye protection provided by the company.

Conduct with your colleagues:

The company sees it as extremely important to encourage and nurture working relationships between its employees. The working relationships between the employees should be based on professional collaborations as vast as possible in a way to that will contribute to the enjoyment at the company and that will promote its goals. This collaboration should include behaving in an honest and fair manner towards their colleagues and in general: share professional knowledge with them, help colleagues who are having difficulties in their work, help new members acclimate in the company and maintaining a working place which is pleasant and functioning.

Remember that you represent the company!

Don’t hesitate to go to your superiors with problems that require intervention.

Part Names

Basic Lesson OrderSpring-Powered Race Car

Worksheet: KH.M.67

Subject: Familiarization with the various kit parts.

Auxiliary Tools: Class attendance roster, spring-powered engine, a modest sweet treat, large wheels.

Lesson Structure:

1. Defining the model built during the lesson.

2. Explain proper way of opening the kit. Explain how you would like the kit returned. Hand out kit arrangement instructions sheet at this stage. Note that the kit must not be closed until instructed otherwise.

3. Getting acquainted with the different Lego parts – see “Getting acquainted with the different parts” outline on the next page.

4. Guided Construction.

5. Enhancements.

6. Game.

7. A riddle for the kids: How does the car travel faster, with small or large tires? Answer: Large tires, for the perimeter of the tire is larger, and with it the distance the car travels with each turn.

8. Packing up the kits – 15 Minutes prior to the end of the lesson.

Notes for the instructor:

1. While looking over this booklet you will notice that this lesson is extremely meticulous in comparison to the rest, this is because this lesson is one of the more challenging during the year.

2. Remember it is not recommended to have more than 25 children during the trial lesson. It is preferable to postpone the extra children to the next meeting, than to cause them disappointment by how the lesson was conducted and hurting its marketing.

3. If there isn’t a sufficient number of kits – encourage working in couples.

4. Mention to the kids that there is a sheet with enhancements that is not mandatory, that they must show the instructor each stage of the building process and that they are not supposed to finish it in its entirety.

Additional notes for the class:

1. During this and the next lesson the instructor is on “treat duty”, and after that during each lesson a different child is to be appointed.

2. A child who wishes to enter the next lesson must make sure a parent signs him up for the class. Whoever doesn’t sign up might not have room during the next class.

Getting acquainted with the different parts outline:

1. Presenting the beam, note it must be measured by the number of heads, and not the number of holes

a. Instruct the children to take out a 16 Beam (or any other large beam you prefer).

b. “Complex” assignment – Let’s see who can find a 2 beam.

2. The different kinds of surfaces.

3. Axles – Its length is measured by placing it on top of a surface (or beam, although not as comfortable) and counting the number of heads it covers up.

Note: Axle connecters and holders – It is recommended to explain these while working and not at this stage.

Guided Construction for Spring-Powered Race Car:

Note before you begin:

1. The construction is easy, verify that each child knows how to measure the parts and not just know them by name.

2. It is possible that the cars will travel faster without the tires, depending on the type of surface. Check it beforehand.

The stages for the Guided Construction – These are the basic stages on the enhancement sheet which you can hand out during the enhancement stage.

Enhancements:

1. Enhancement sheet or freestyle enhancements.

2. Very Important: If there is a problem with the car movement, replace the 6 axle (during phase 2, connected to the spring engine) with a 10 axle, this will cause the car to travel more fluidly forward.

It is highly recommended to let the kids freely explore their own enhancements and race between themselves. A child that beats his classmate 5 times gets a treat, and at the end of the lesson hand a treat to those that didn’t win any.

Pirate Ship

Worksheet: KH.U.61

Subject: An unstable structure in comparison to a stable one.

Auxiliary Tools:

· Toilet Paper (Closed), a string tied to the paper.

· Sweets – Remember, “sweets duty” is filled by the instructor first 2 lessons.

Lesson Structure:

· Tell and demonstrate “something that happened yesterday”, where one of the children didn’t close a kit properly and it spilled in your car.

· A short refresher course on the main Lego block names.

· Exposure to the term “structure[footnoteRef:1]” in Lego. [1: Structure – Every 2 parts or more, connected to each other.]

· Expose the class to the terms stable and unstable structures, and explain with an example (2 parts, on top of each other and not connected in any way – a structure, but unstable).

· Explain and demonstrate the 2 connecting methods: affixing[footnoteRef:2] and sticking[footnoteRef:3]. [2: Affixing Method – Connecting with nails. Connecting with 2 nails creates a stable structure, and by one nail creates an unstable structure. ] [3: Sticking Method – A beam connected using a line. Connecting by 2 lines, one on top and one on bottom creates a stable structure, while one line creates an unstable one.]

· Give an assignment (race) – Build a stable structure as long as possible with either the affixing method or sticking method. Measure the time for this.

· Explain the procedure for working with the worksheets:

a. The instructor is seated while the children come up to show him each and every stage. A child having difficulties is to wait in line with the rest of the class.

b. No moving on a stage without first showing the instructor.

c. The axle key is on the instruction page – note that it’s referred to the small number next to the axle.

d. The bright parts in the photo are parts already built at a previous stage.

e. Arrows – in case of arrows, follow them until the end of the stage.

Additional riddles for “Engineers”/”Head Engineers”:

This is to be asked after the build, when the built model is in front of the kids:

Take the toilet paper and tie around it a long string. Now, show the kids that by spinning the string at a constant pace we get a circular motion of the paper at a constant pace. Keeping this pace you shorten the string by putting 2 fingers in the middle of the circle, you get a faster speed. The question is why? And the answer is that this happens due to the length of the circle growing shorter, the perimeter is smaller. From here, if we want the ship to go faster, do we want a shorter or longer axle? Answer: Shorter.

Compare the ship to this model, and ask whether a ship with a long axle is suitable for small or big children? Answer: Small, for the ship won’t make a full circle and will move faster in comparison to one with a small axle.

After construction:

Form A: Build a ship with a short axle.

Form B: Build a ship with a long axle.

Question: In which case is the operator to use more force to turn the ship a full circle (360 degrees)?

Answer: Form B, for the distance the ship has to make is greater than in A.


· Please make sure that the children present in the class have finalized their registration de facto.

· Close to the end of the lesson hand out the instructions to organizing the kit.

· Give out a treat for each child and don’t forget to nominate someone for “sweets duty” for the next lesson.

Enhancements:

1. Elevate the boats center columns in a stable manner – preferably with the sticking method.

2. Build an actual ship on the swinging axle.

3. Add a steering wheel.

4. Add wheels

5. Add an engine – See pictures. Note:

a. The engine seats on two 4 beams, and two 2 beams.

b. The rubber band should be fitted on the red bush.

c. Remove any additions to the ship interfering with the engine.

Conveyor Belt

Worksheet: KH.M.63

Subject: Presentation of the different motorized equipment, learning the term: transmission, transmission band, impeller, driven pulley.

Auxiliary Tools:

· A large number of rubber bands and a stockpile of sugar cubes, engine, battery cases and electric wires.

Lesson Structure:

1. Presentation of the engine, battery housing and the electric wire.

2. Explanation of safety procedures and proper maintenance of motorized equipment – see below.

3. Explanation on the origin of the name “Conveyor Belt”.

4. Where do we see conveyor belts? (Supermarket, Airport, Factory, Escalators)

5. Definition of the word transmission – what are we transmitting? From the impeller to the driven pulley.

6. Definition of Transmission Band – Round delivery using a strip (in our case a rubber band). Draw on the board.

7. Defining impeller (the wheel where the rotation starts) and the driven pulley (the wheel “receiving” the rotation)

8. Construction.

9. Playtime and enhancements.

Explanation of safety procedures and proper maintenance of motorized equipment:

1. Demonstrate asymmetric propeller constructed on an engine axle, note that the resulting vibrations ruin the magnets in the engine.

2. Do not pull the electric wires – the act loosens the contacts.

3. Do not connect ends of wires to each other – taking this apart loosens the contacts.

4. Note the engines are very expensive.

5. Be careful not to drop engines. If a child drops one – prevent him from taking one for 10 minutes. (Be sensitive about this subject).


To this point we haven’t spoken of the exchanging of speed into force, and vice versa. With this riddle we’ll prepare the children for the next lessons where we’ll work on the differences between speed and power increasing transmissions.

The Riddle:

If you were the engineers of the “Coca Cola” company, and your manager asked you to build a conveyor belt, would you build a slow or fast one? Answer: slow. What type of transmission would be required? Answer: a small wheel turning a big wheel - we’ll learn about this later.

Technical explanations on the construction:

1. On stage 6 there is a red 4 plate, it goes in on its side – test and learn.

2. After the children come up to show stage 7, prepare them for stage 8 by explaining about the arrow placed for turning the model 180 degrees.


· Assist the children with placing the rubber bands properly.

Enhancements:

· You can exchange the impeller with a larger wheel to make the conveyor belt move faster.

· A chest that the sugar cubes will fall into.

· Build a conveyor belt with an upwards incline.

· Two children or more can connect their belts together.

· Every child can build an extra conveyor belt, a little taller than the first, and connect them horizontally. With the same method and little engineering skills, you can connect them in a 90 degree angle as well.

Power Plant

Worksheet: KH.M.55

Subject: Gear transmission, and introduction to the subject of power increasing transmission.

Auxiliary Tools:

· A large number of transmissions constructed on top of a single beam, starting at the smallest wheel and ending in at the largest.

Lesson Structure:

1. Story.

2. Presentation of the gears and their names.

3. Experience – Pick a volunteer to try and turn the beam built on the “Auxiliary Tools” section. He should try first from one side (small wheel) and then form the other (large wheel). Which side is easier? Answer: Smaller wheel. Conclusion: A transmission where a small wheel turns a larger one has more power, and therefore we need less of an effort to turn it.

4. Construction and enhancements of the model.


With this riddle we’ll prepare the children for the different relative transmissions. We’ll see that we get more speed.

A 40 gear turns an 8 gear. What do we get? Answer: 8+8+8+8+8=40 i.e.: In a single turn of a gear with 40 teeth, we can fit 5 smaller gears. Therefore, turning the larger wheel will cause the “smaller” one to turn 5 times.

Enhancements:

· Extending the propellers.

· Creating a large number of propellers.


Stage 14 is missing – An error with the numbering, there are no stages missing.

Story:

In the past people wanted to invent machines working on belt transmissions (Draw). What do you think would have happened if the band had broken? What if the band had stretched too much? What if it was too tight and there was a lot of friction – the answers are identical: there would be no rotation and therefore no transmission.

Then came a great Chinese inventor (named “Chukumukulukuruku”), and invented the gears.

Hence, the difference between belt transmissions and gear transmissions is the distance between the impeller and the driven pulley, and the direct contact between gears as opposed to indirect with the band.

At this stage, show that the gears turn in opposite directions and ask: In the past they built tanks with gears on both sides, but the tank would move. Why? Answer: Each gear would turn in a different direction and therefore the tank wouldn’t move. The problem was solved with an idle gear[footnoteRef:4], placed between the former two, and the tank moved forward. [4: An Idle Gear is a gear not used to move the machine and is supposedly not needed. In the models in the course we’ll use idle gears as gears in-between 2 other gears (one on the left, other on the right), enabling the right gear to turn in the same direction as the left one.]

Draw the idle gear on the board in the transmission between two working gears.

Enhancements:

1. All the enhancements in red.

2. Increase the number of propellers and transmissions.

Manual Electric Beater

Preparation of Vanilla & Cookies Ice Cream

Worksheet: KH.M.62

Subject: Electronic circuit, electronic engine, electric wires, battery housings, the word “beater”.

Auxiliary Tools:

· Spoon, disposable teaspoons, small disposable cups, bowl, napkins.

· A few spoons of instant vanilla pudding = No. of children * (1/3)

· E.g.: 15 children times a third = 5 cups of pudding.

· A mixture of cream and milk by these calculations:

· Cups of milk = Number of children * (1/6)

· Cups of sweet cream = Number of children * (1/30)

Note: Prepare the mixture at home and keep it refrigerated in the kitchenette or teacher’s room.

· A few Biscuits.

Lesson Structure:

1. Presentation of the engine, electric wire and battery housing.

2. A comprehensive explanation on the engine, the battery, the “volt” unit.

3. Present the word “beater”.

4. Construction and enhancements.

5. Mixing and the addition of biscuit crumbs to the mixture.

6. “Lick, wash, and organize kit” – Afterwards give out the ice cream in cups. Pay Attention!!! Danger of swallowing parts that have fallen in the mixture!

Comprehensive explanation on the engine, the battery, the “volt” unit:

1. A comprehensive explanation on the engine[footnoteRef:5]. [5: Inside the engine that are to magnetic poles of plus and minus. There is an axis that vibrates. The explanation is outlined later in the lesson plan.]

2. An explanation how a battery works.

3. Explanation on electric circuits – open & closed circuits, switch[footnoteRef:6] (given using the light switch in the classroom). [6: Electric wires are made of conductive materials – kinds of metals, in our case, copper.]

4. Explanation of the unit “volt[footnoteRef:7]”. [7: Explain that in the same way distance is measure in Kilometers and weight in Kilograms, voltage is the amount of electricity and it is measured in volt.]

5. Explanation on the battery housing – 6 batteries, 1.5 volt per battery = 9 volts in all.

Battery Makeup:

1. Negative side.

2. Positive side.

Electronic circuit:

Made from a collection fo electric components, connected using conductors, and in a way which permits the electric current to flow through. For the current to flow two conditions must be met:

· The circuit must be closed.

· The circuit must have a power source – the battery.

Electronic engine:

Its function is to take electric energy and turn it into a rotating motion.

Note that the into the engine in the illustration go two wires, one with a positive charge, and one with a negative charge. This causes a magnetic field on to the wire looped around the engines axle. With this magnetic field, the rotation is started when placed between 2 opposing magnets.

A reminder on magnets: Same polarities repel, opposite polarities attract.

Illustration key: There are two magnets on the outside, and two coils on the inside which are magnets as well.

On the left picture the blue coil is magnetized like the north pole, and is therefore repelled by the “north” pole (“N”). The pink coil is magnetized like the south pole and is therefore repelled by the “south” pole (“S”). The repelling forces turn the axle in a clockwise manner. In the middle picture the blue coil is repelled by the blue magnet (north) and is also pulled towards the pink magnet (south). Using these repelling and attracting forces the rotation of the engine axle is created.


Which metal conducts electricity in the best manner? Answer: Gold.


· Keep proper hygiene – There was a case where one of the children didn’t keep the beaters clean after washing them, used them to mix, and then no one could taste what was created.

· Do not connect the beaters until after the enhancements so while fiddling with it the entire axle isn’t pulled out.

· Do not enhance the beaters (this causes ricochets or greater resistance in the mixture, and therefore no whipping).


· Follow up each explanation with an illustration on the board – Battery, electronic circuit, switch …..

· Wash the beater both before and after its usage.

· To refrain from causing a mess during whipping – insert the beaters as deep as possible into the bowl.

Enhancements:

· Extend the handle.

· Build an “engine cover”.

Windmill

Worksheet: KH.M.49

Subject: Belt transmission, speed increase, power increase.

Auxiliary Tools:

· Rubber bands, model created beforehand (See picture after the story).

Lesson Structure:

1. Start the lesson with a personal story – See next page.

2. Draw the building and the different stages described on the next page.

3. Repeat the terms “transmission” (round delivery), “impeller” and “driven pulley”.

4. Explain about speed increasing transmission – a large wheel turning a smaller one, as described in the story.

5. Prepare beforehand a beam with a large wheel turning a small one and demonstrate to the children at the end of the story.

Remember: Make sure that all children have paid for the class.

Notes for the instructor: When a large group of children arrives at the same time they must each wait their turn in line, but if the instructor sees a number of children at the same stage – get their attention and explain at the same time rather than one by one.

Personal Story:

I live in a 5 story building. I live on the first floor and my good friend Shay lives on the fifth. One day, while sitting on the balcony, I heard Shay calling me. He told me he was reading a book when suddenly his fan stopped working. My friend Shay, whom I forgot to mention is today a Mechanical Engineer, started to sweat, and the sweat dripped on the pages of the book causing them to stick, and instead of turning a single page he turn five, which confused him. Because of the frustration, he decided to take off his cloth and stay only in his underwear and keep reading on the balcony – when his mother noticed this she yelled at him “Come inside this instant! You’re embarrassing me in front of the neighbors!” After getting dressed Shay said he has an idea how to solve the problem. He proposed: “Maybe we’ll turn the fan by hand and not using electricity, so that you sit downstairs and turn my fan from the first floor?” My response: I laughed and thought he was crazy and asked him: “How?” he answered that we’ll meet at the entrance to the building. I went and when he arrived he said that in the yard there are: wheels, ropes, nails and other stuff lying around. At this point ask the children if anyone has an idea how to complete the task using these. Solution: Belt Transmission – See drawing:

At the entrance to the building there were small and large wheels, at the beginning I brought a small wheel from my bicycle, but even though I spun it around quickly, Shay was still hot and my arm really hurt!! See drawing:

** Note the wheels are the same size.

Downstairs: Impeller. Upstairs: Driven pulley.

Therefore, we switched the small wheel with a larger one – my dad’s bicycle wheel. And indeed, the fan started rotating faster and Shay was satisfied. This is a speed increasing transmission.

Perform the following change on the transmission in the drawing:

Conclusions:

· When both wheels are of the same size, rotation speed is identical.

· When a large wheel turns a small one, we gain more speed (and less power, but don’t mention this yet).

· When a small wheel turns a large one, we lose speed (and gain power, but don’t mention this yet either).

At this time present the model prepared beforehand demonstrating the speed increasing transmission mentioned in the story.


Here are the questions the children should be asked as they present the stages:

1. Stage 5 – Go over the turning direction of the gears.

2. Stage 6 - Go over the turning direction of the gears.

3. Stage 7 – Which gears has a faster turning speed? Why?

4. At stage 9 – Triple transmission.

Enhancements:

1. Add as many propellers as possible using a belt transmission.

2. Make the propellers cooler by extension, adding shapes, etc.

3. Belt transmission for the wheels so the model moves.

The Lever Principle

Worksheet: KH.U.60 + KH.U.2

Subject: The lever principle – fulcrum, force arm, load arm, torque.

Auxiliary Tools: Knitting thread.

Lesson Structure:

1. Announce that today we'll be learning how to lift the school with a pinky.

2. Write Archimedes’ words on the board: "Give me a lever long enough, and a prop strong enough, I can single-handed move the world."

3. Draw a seesaw with 2 children, one fat and the other skinny and ask who will go ascend and who will descend. We'll soon see the fat one ascends. (Be sensitive about describing the fat child, his name, etc.)

4. Define the terms: fulcrum, force arm, load arm – use the seesaw on the board.

5. Explain that if we had extended the seesaw the lighter child could life the heavier one. Note this force is called "torque"[footnoteRef:8]. [8: Torque = length of the arm X the force used on it]

6. Story.

7. Model construction – In a regular class the KH.U.60 lever is recommend. Afterwards if there's time KH.U.2 is recommended.

8. Trick – after constructing the tweezers and the extension, collect 2 tweezers, one with the extension and one without, also pick a volunteer and make him stand on a table so all could see. Tell him to turn his back to the class and that he will be pinched once with each of the tweezers, so the class will see that he notes the extended one is stronger (painful). First pinch him with the small tweezers, and then instead of using the large pair, pinch him (medium strength) with your hand – the children really laugh if done correctly. After, of course, ask which one hurt the most.


· In a weak class you can focus only on KH.U.2. On the other hand the ideal with standard classes in this lesson is KH.U.60 and after the tweezers on KH.U.2.

· Tell the story with enthusiasm and put an emphasis on the jokes appearing in it.

· On one hand the construction is quick, but still there are children who won't finish all models on time. Therefore, extending the story duration isn't enough, but tell the kids that there are 4 models and we might not finish as well.

· Torque = the product of the force used on the arm and its length.

Story:

Once there was a man named Joseph, and he had 7 children. He was an old man at the age of 57. He worked at a carpentry shop (Anyone know what does a carpenter do?), and his boss (explain what a boss is) told him that because they don't have a lot of work, there are many workers with nothing to do. What the boss was trying to say without hurting his feelings is that he was fired.

Joseph was really depressed (sad) and didn't know what to do. How will he be able to feed his wife and 7 children? He sat on a bench in his neighborhood and started thinking… and thinking. Suddenly, Joseph remembered that his father left him some land in his will (start drawing here), so he will sell it to get money to purchase food. But, to his disappointment, nobody wanted to buy the land because of its location. Joseph then decided, if he has so much landed, I will grow wheat on it (who knows what wheat is used for?), fruit, vegetables, eggs, etc.

Joseph woke up early in the morning, and decided to go and start working the land. He awoke at 6 in the morning, and got dressed. He put on a shirt, a pair of pants, socks and a pair of shoes. Only after leaving the house he remembered he didn't wear any underwear, so he went back inside, took it all off, and got dressed again. He went out to the field and his eyes went dark. The entire field was full of beams, nails, rocks and particularly a very large rock. See illustration:

Joseph said: "OK, in order to grow the crops I first need to clear the land, so here goes, I'll start right now!"

On the first day he cleared all the beams, and put them on the side. On the second day he awoke early also to start work early but this time he accidently put on his shoes before his pants and so he got stuck as he was trying to put them on. Thankfully his wife was home so she helped him squeeze his shoes through his pants, and only then did he finally leave, late. On this day he cleared all the nails and put them on the side. On the third day he woke up prepared, had a cup of tea without any mistakes and left early to start work on clearing all the stones. He cleared all the stones but there was one that he couldn't lift, the large one in the center. See illustration:

Joseph tried to pull the rock, push it, even lift it (bend your knees to demonstrate) – he tried really hard until he suddenly heard "rrrriiipp", he turned around and saw that the backside of his pants is entirely ripped!! It's a good thing he didn't forget to put on underwear!! He quickly called a cab and went home, he was embarrassed that people will see him.

When he arrived home he went back to his bench but was depressed again because he didn't know what to do about lifting the bug rock in the middle of the land. Out of nowhere he started yelling "Yes!, How Fun!" and started jumping around the street. People turned to him and asked: "Joseph, what happened that made you so happy?" and what did Joseph answer – I found a way to remove the large rock from my field. And that's how it was, half an hour later the rock was out of the field. Anyone know how he did it?

If the children don't come up with the answer, hint they used the 3 materials: rocks, beams and nails.

Answer: Joseph constructed the load arm out of the beams and nails:

Afterwards Joseph placed a stone to be used as a fulcrum, and by using both of these he caused the large rock to roll out of the field:

Additional Notes for the Class:

Remind the class – A good engineer is an engineer who counts, whoever doesn’t count the heads and the holes – will make a mistake. Additionally, we don’t have enough time today for all the models.

Model Construction Outline:

KH.U.2 – As mentioned for standard class the emphasis is on the tweezers only.

1. When the child arrives with a white stage 3 – tell him to keeping going with the extensions with either the affixing or sticking method until a different result is received.

2. When the child returns to show his work, explain that the side to the right of the axis (where the weight is) is still heavier, but due to the lever concept we get that the lighter side lifts the heavier one (because of the torque created, not the weight).

3. After a blue stage 2 – Ask the child where will the tweezers hurt more. Answer: stage 3.

4. Enhancing the wheelbarrow, red stage 1 – Here, once again, extend the poles as much as possible and this way it will be easier to carry.

KH.U.60

1. On stage 5 – One of the parts is a 4 plate. Its function is to create friction, and postpone the dropping of the weight once we stop turning.

2. On stage 7 – Exchange the Lego block with a 4 plate.

3. When the child arrives to show stage 9 – Place the string with the weight on the higher pulley. The Result: The model will lean and fall forward. Note that the drop is contradictory to the stability on stage 7 when the string is placed on the middle pulley. Go over with the children on the effects of the lever principle on the fact that on stage 9 the model fails as opposed to the stability of stage 7.

Enhancements:

1. Detailed in the model construction outline and on the worksheet.

2. AN engine can be added on stage 9. Place an 8 gear on the engine in a way that the 8 gear’s motion will turn the 40 gear and thus the entire system.

3. An engine can be added after stage 9. It is recommended to place a bush on the engine and replace the 40 gear with a large steering wheel, and connect them with a belt transmission. It is recommended to use a belt transmission, rather than a gear transmission which is easier, for that fact that using a gear transmission will cause the string to break if we don’t stop the engine on time.

Motorcycle

Worksheet: KH.M.52

Subject: Speed increasing transmission, angular momentum conservation law, law of inertia.

Auxiliary Tools: A rubber band.

Lesson Structure:

· Explanation on the word “motorcycle[footnoteRef:9]”. [9: Motorcycle is made up of the words motor and cycle – It is possible to elaborate on motorcycles and on the kind of motorcycles having 3 wheels.]

· Explanation on the word angle and on the connection between the stability of a motorcycle on the road as a function of the angle it is in.

· Define the angular momentum conservation law[footnoteRef:10]. [10: Angular momentum conservation law – the speed in which a motorcycle travels maintains a 90 degree angle in relation to the ground it is on.]

· Explain about stability ni the way described in the “additional explanation” section.

Additional Explanation:

Law of inertia: A mass will continue in in its original direction unless affected by an opposing force. Driving a motorcycle at a fast speed maintains a 90 degree angle unless an outside force will cause it to destabilize (just like a spinning top stays upright while it’s spinning). A motorcycle with 2 wheels is unstable and isn’t suited for driving in town when the driving speed is slow and you need to stop occasionally. Therefore, in towns with a lot of traffic, motorcycles with 3 wheels are common.


Keeping in mind the law of inertia, what are the opposing forces affecting the motorcycle and slowing it down? Answer: The different kinds of frictions (with the air, with the road, frictions inside the machine, etc.).


There is a friction problem with the bushes, which slows the ride and even puts it to a halt. Make sure the bushes aren’t closed too tight on the axles and cause friction.

Enhancements:

· The addition of a dolly to the motorcycle.

· A trunk.

· Increasing the speed by exchanging the impeller with a larger one.

Amusement Park Carousel – Chair-o-Planes - Manual

Worksheet: U.14.1

Subject: The centrifugal[footnoteRef:11] force in comparison to the centripetal force, crown gear. [11: Rotational energy – A daily example of the centrifugal force is the feeling we get of being pulled outside in a turning car or in a carousel. The faster the carousel goes, the stronger the force, the harder it is to stay on.]

Auxiliary Tools:

· “L” shaped beams showcasing the technique used with a “crown” gear (See the picture included in the lesson plan.

· A frisbee tied to 4 ropes and a disposable cup filled with water.

Lesson Structure:

1. Showcase the proper use of the crown gear:

2. Present the centrifugal force. Demonstration: Turn around yourself with your arms relaxed and show the kids what happens when you increase your speed (they go up).

3. A demonstration of the frisbee spinning quickly without the cup of water falling:

a. Pick a child, ask him if he shampooed his hair today and perform this over his head.

b. At first turn the frisbee slowly and quickly increase the speed. When you stop “follow the frisbee” for this is the most dangerous part of the trick.

c. Announce that this is not magic, and that a physical force is at play here and will soon be explained.

d. Tell the story about the trick.

4. Explain about the terms centrifugal and centripetal forces, and explain using Fugal and Petal. Define that the centrifugal is the force pushing outside the center of the circle (a circle with arrows pointing out), and that the centripetal is the force keeping items from disconnecting from the main body (draw a circle with arrows pointing in) same as it appeared in the trick in the form of the force keeping the cup of water from falling off.

5. If you wish you may use the term “reinforced concrete”.

Story:

1. Fugal and Petal, 2 sisters that are always arguing. (centri) Fugal always wanted to play outside while (centri) Petal always wanted to stay at home. You can freely use your imagination to develop the story.

2. Last year while performing this trick in front of a class only I didn’t have any water. I asked one of the students for water but he didn’t have any so I used a cup of coke. I turned spun the frisbee and the experiment was successful. Afterwards, I told the children not to try this at home since it’s dangerous.

In spite of my warnings, one bright day one of the children decided to try it at home. He invited his grandmother to sit on the couch with his grandfather sitting beside her. He called his sister and parents as well to watch the trick he’s going to perform. And what do you think happened? The second he began the coke cup fell and spilled all over his grandmother… Immediately his mother started screaming “look at what you did to grandma! Go to your room and don’t come out until tomorrow!”

Conclusion: Don’t try this at home!


· Joseph was turning in the carousel when the chain suddenly broke. Where will he fall? Down? Far? Answer: Far. In a state where the chain breaks away from the carousel the centrifugal force “overpowers” the centripetal force. Lucky thing is that Joseph fell on top of the trampoline placed at the amusement park and came out unscathed.

· To what angle will the carousel arms rise? Answer: 90 degrees – a right angle. Question is why: Answer – the items want to be thrown out of the carousel and at a higher angle a different kind of energy is required, which is not defined as centrifugal.


· Make sure that the 8 gear is in contact with the crown gear.

· Use only the grey nails (without the black ones).


1. Emphasize the endings “fugal” and “petal” when writing on the board.

2. Make sure you have a sufficient amount of axle connectors.

Enhancements:

· Make the carousel structure more rigid.

· Add additional chairs using axle splitters.

· Extending the main carousel axle and thus making it higher.

Laundry Machine

Worksheet: KH.M.66

Subject: Centrifugal force, the washing machine's wringing operation, belt transmission.

Auxiliary Tools:

· Water bottle with holes at the bottom, a rope tied around the bottle's neck, a bit of cotton in the bottle.

· Lots of cotton for the children.

· A bowl of water (for soaking the cotton after constructing the model).

Lesson Structure:

· Demonstration of the centrifugal force – using the "drum" (the bottle with the holes).

· Illustrating the washing machine.

· Story about a laundry machine – Grandmother & Grandfather.

· Explanation of the drums operation[footnoteRef:12]. [12: Inner drum – the perforated cavity to which clothes are deposited and where water drains through the holes.]

· Explanation of the washing machine's wringing operation[footnoteRef:13]. [13: The drum is perforated. As it turns, a centrifugal force is applied and as a result – water drains out of the holes. ]

· Explanation of speed increasing transmission.

· Construction.

· After construction is complete – soaking the cotton, inserting it into the laundry machine and observing the wringing operation.

· Enhancements.


· Centrifugal force demonstration – Spin the bottle (with the perforated surface pointing downward, and in it – some soaked cotton) using the rope – the wringing operation is demonstrated as water drains through the holes.

· After construction is complete, insert a 2 beam into the drum and operate it upside-down. Explain that without the spinning of the drum – the beam would have fallen. At this point the instructor should ask what type of force is preventing from the beam from falling:

(Centripetal):

Story:

My grandmother had her 70th birthday and my grandfather asked her what she would like to have as a birthday gift. She asked for a laundry machine.

My grandfather went to an electrical supplies store, in which electrical appliances are sold, and asked for the very best and most expensive laundry machine they have.

After buying the machine, grandfather returned home. Grandmother and him got so excited and began filling the new machine with all the clothes and bed sheets they had… until there was no more room for more clothes, and grandfather began using more and more force to get more clothes in. At this point it should be demonstrated that grandmother and grandfather could not close the laundry machine's door so grandfather held grandmother and tried to close the door while pushing it with his foot, and as a result both of them fell on the floor (this part of the story should be funny, therefore it is important to use body gestures in order to achieve this goal). They then turned the laundry machine on and waited. Do you think the clothes came out clean?? No!!!

Grandfather immediately phoned the electrical supplies store and said he was very angry. "I thought that the most expensive laundry machine would at least clean the clothes" said grandfather.

The salesman than asked: "did you plug the machine to the electricity?" 'Yes' said grandfather. "Did you connect the machine to a water source?" asked the salesman.'Yes' said grandfather."Did you add some detergent and a fabric softener?" asked the salesman.'Yes, yes' said grandfather."So please explain exactly how you operated the laundry machine"Grandfather then explained that he and grandmother squeezed clothes in the machine so hard, that they both fell on the floor. At this point the salesman stopped grandfather and explained that in order for the clothes to get clean – they must have some friction because it is the friction between the clothes that get them clean. When too many clothes are squeezed in – there is no room for friction to be created.


Red stage 7: this is a transformation of stage 5. Instead of using 2 beams, use 6 beams, and instead of 4 beams, use 8 beams. Furthermore, it is not necessary to enlarge the drum during this stage.

There is an option to enlarge the drum using any rigid method, as long as it is symmetrical so that it doesn't vibrate (in this manner, a rectangular drum is also symmetrical in relation to the central axis of the drum).

Enhancements:

· Red stage – building an additional drum for the laundry machine: pay attention that it must be symmetrical and in the name of better convenience it is advised to attach the extra drum on top the existing one.

· Drums on both sides of the laundry machine.

· Building a portable laundry machine.

Flywheel – The crazy clown (A Ride at Euro Disney)

Worksheet: KH.U.6

Subject: Flywheel, transforming from a circular motion to a linear motion.

Auxiliary Tools: The model being built without the propeller (which constitutes the flywheel).

Lesson Structure:

1. Presenting the flywheel – see "Explanation outline for the flywheel".

2. Story.

3. Explanation of the terms circular motion and linear motion[footnoteRef:14]. [14: Linear motion – The displacement of an object along a straight line. Linear motion is normally restricted to border limits. ]

4. Explanation of the term flywheel – should be demonstrated with the model without the propellers at first in order to illustrate how the flywheel helps us. The instructor should be ready with a constructed model and disconnect the propeller. At this state, using the pedal should not spin the 40 gear a full rotation. It should be demonstrated that only after attaching the propeller (which constitutes the flywheel) the 40 gear will make a full rotation.

Notes for the instructor: Draw a lot in order to illustrate.

Explanation outline on the flywheel:

1. Display the following model to the class:

2. Spin the propeller and count how many seconds it turns with the children.

3. Afterwards ask the children if they can think of another method in which the propeller would spin for a longer time.

4. Display the following model:

5. Spin the propeller and count how many seconds it turns with the children. Together you should come to the conclusion that adding weights to the propeller makes it spin for a longer time.

6. If so, would it be right to overload the propeller with weights in order to help it spin for several minutes? Answer: of course not, since the heavier the weights are – the greater the friction is!

Story:

When I was a child, there was a new immigrant from Ethiopia named "Kola" living next door. Kola was a seamstress. Her sewing machine was a manual one, in which she had to turn a wheel for it to work. Therefore, she could only sew few clothes every day. One morning, Kola's husband, Abraham, told her that now that their family has grown, they will need a greater income. It was necessary for Kola to sew more clothes every day. She said it couldn't sew faster for she only has two hands – one holding the cloth and the other spinning the wheel. See drawing (ignore the bottom wheel – it was only added after Abraham's first word of advice):

Note: You could add a glass of coke and tell how much she liked to drink coke when sewing.

Kola's husband, Abraham, had a friend named Moshe. Moshe was a brilliant man, and for that reason Abraham asked him if he could think of a solution for the rate at which they could sew clothes. Moshe suggested spinning the wheel with the leg rather than the hand, while freeing the other hand. Abraham ran gladly to Kola and told her of Moshe's idea. "Are you crazy?!" said Kola. "If I do what you are suggesting everyone will see my underwear! I'm an old lady!!". Abraham returned ashamed to Moshe and together they sat down to think of a better idea. Moshe then came up with an ingenious idea. He suggested using a pedal in order to spin the whole system using the leg. When Kola was pedaling, the wheel didn't spin a full rotation but only half of one, so we added weights to the wheel – therefore transforming the wheel into a flywheel. See drawing:

Enhancements:

· Extend the momentum handle (using the affixing method, using a 4 beam), a procedure that will allow a full rotation using less effort (according to the lever principle).

· The red stages.

· Pay Attention: After the red stages, one can turn the model on its side and spin it in way that resembles a merry-go-round.

· Attach an engine.

Towing and Towed Vehicle

Worksheet: KH.M.53

Subject: Towing axle

Auxiliary Tools: Small and big wheels.

Lesson Structure:

1. Story.

2. Definition of the term towing axis.


· The story should be accompanied by illustrations.

Story:

I have told you of a friend from my past, and now I would like to tell you about a friend of mine named Mary: we used to go to the same school when we were younger. The school was built at the top of a high hill. In the summertime we would walk to school using a direct path. But in the winter, when it was raining, the path was full of mud, rocks and snakes. It was very dangerous. My mother wouldn't let me walk through the short path and would make me take the long one. The long path would take us 45 minutes! We would walk for over an hour and a half every day!! One day, as we were walking to school it started raining. Puddles of different sizes started to form and we had enough of walking through the long path every time it rained. Mary suggested we should build a vehicle: a wooden sheet with four wheels attached (an illustration should be drawn now!). But it didn't work. Next, I suggested we should ask Moshe, the school's janitor, for a table board, but he did not agree to that. He said: "school's property should not be vandalized". Mary and I did not give up and begged Moshe, until he finally sent us to the principal so we could ask her if we could have one of the old tables standing in the warehouse. Lucky enough, the school's principal was a good friend of my neighbors Mrs. Kola. She agreed immediately. We took one table board, two wheels from a broken grocery cart and two wheels from Kola's chair. Finally we also tied a rope to our vehicle.

We argued a bit on who would be the first to get on our new cart. As a good friend I offered Mary to go first and that I would push her so she would have some momentum. She agreed immediately. I pushed the cart strongly, Mary couldn't stop and crashed into a puddle of mud getting all of her clothes dirty (Draw the curved path and centrifugal force that beat Mary and caused her to fall into the puddle on the side of the path). Mad – Mary came over and said that it was my turn now.

But I wasn’t going to fall for that… I was going to make some enhancements before I get on that cart. I sawed the cart and added an axle attached to the front part of the cart with a nail (This should be drawn!).

When I wanted to turn right I pushed with my left leg, and when I wanted to turn left I pushed with my right leg. As a result I could go down the whole hill without falling. We will now build this cart, children.

Technical information about the construction:

· In weaker classes, it is recommended to build the model in pairs - one child does the white stages, and the second child does the yellow stages.

Enhancements:

· The battery housing can be placed on the towed cart, so it can then drive independently.

Crane

Worksheet: KH.M.68

Subject: Double power increasing transmission.

Auxiliary Tools: Sewing thread, scissors.

Lesson Structure:

1. Definition of the term "Crane" and its origin – named after the long-legged and long-necked Crane (bird).

2. Explanation of the cranes' shape and the weights positioned on its back side (see illustration below).

3. Review on the double power increasing transmission – a small gear rotating a larger gear.

4. Learning the topic of double power increasing transmissions: see double speed increasing transmission at the "Spinning Top Launcher" lesson. A change must be made to the illustration – pedal must be placed on gear D, in order for it to begin the motion.

5. Review about tying a rope to an axle.

More riddles for "Engineers" / "Head Engineers":

Draw a "tower crane" and ask where on the crane should the weights be attached and why? Answer: At the far end of the short horizontal jib. The weights are placed there so the crane doesn't crash as it lifts loads on the long horizontal jib.

Notes for the instructor: Relatively difficult construction.

Enhancements:

1. Add gears.

2. Build a shipping container that the crane can lift.

3. Build a vehicle to which weights can be added. The crane should then pick the vehicle up.

4. Think of a method of lifting cargoes at a higher speed. Solution: Replace the large gear with the smaller one. Disadvantage – less power, more effort needs to be put in.

Steamroller

Worksheet: KH.M.65

Subject: Symmetry and Asymmetry, Centrifugal force and the relationship between the three.

Auxiliary Tools: Aluminum foil, rubber band.

Lesson Structure:

1. Explanation on the steamroller.

2. List of vibrating machinery (vibrating drill, massage chair, cell phone, play station…).

3. Explanation of the terms: Symmetry and Asymmetry. An illustration should be made on a drawing board and a demonstration as well (this can be done by attaching a 40 gear to an 8 plate in an asymmetrical manner, and connecting them to an engine, which should cause the construct to vibrate).

4. Review of the centrifugal force and the result of combining it to an asymmetrical construct[footnoteRef:15]. [15: The phenomenon observed from the combination of an asymmetrical construct to a centrifugal force is vibration. When an asymmetrical construct spins it vibrates.]

5. Explaining the reason why the combination described above causes a vibration[footnoteRef:16] [16: As is well known from the definition of the centrifugal force, spinning objects tend to move from the center outward. Let’s assume an object A, placed asymmetrically on a spinning wheel. We will soon be convinced that at time t, object A will tend to move from the center outward (for example: upward), but as the wheel turns, and at a different point in time, object A will tend to move in a different direction (downward). This motion, occurring throughout the spinning of the wheel is called vibration. ]


1. The engine's instructions forbid from connecting an asymmetrical propeller to the engine. This prohibition is not over-ruled in this model since the asymmetrical construct is attached to the driven gear. If we were to use a gear transmission, the vibration would indeed reach the engine's axle and destroy it.

2. After the model is assembled, aluminum foil should be given to each student. The students should flatten the foil.

3. At stage #5 – a common problem is the friction between the 4 beams and the bushes.

Enhancements:

· The asymmetry can be made more extreme in order to strengthen the vibration.

· A moving steamroller can be built.

Vehicle from the 20's

Worksheet: KH.M.57

Subject: Chain transmission (only if chains are at reach).

Auxiliary Tools: Rubber bands, chains.

Lesson Structure:

1. Reminder of the different transmissions taught (Belt transmission and Gear transmission).

2. Presenting the challenge: A vehicle with its engine placed in the center, transmits power to one of the wheels through a belt. The belt brakes and there are no more belts. Solution: replacing the pulleys with gears, and filling the space between the gears with more gears. Challenge: multiple gears create a lot of friction. Solution: chain transmission – distant gear transmission with the minimum amount of friction.

3. Exposing the class to the chain transmission and explaining it.

4. Examples of different uses of the chain transmission (Tank, Bicycle, etc…).

Additional riddles for "Engineers" / "Head Engineers":

Opening state: two adjacent gears. Let’s assume that the right gear is the impeller. In addition, there is a chain transmission connecting the two gears. For medium classes or as hint – three states of transmission can be drawn: The first of the two gears. Ask the students for the directions the gears will turn ("If this gear turns left, the other gear will turn…?").The second transmission will be constructed of two distant gears with a chain connecting them. Ask the students for the directions the gears will turn.The third should be the one presented at the beginning.

Notes for the instructor: Construction is easy and simple; therefore the students should be motivated to enhance their models before given the engines.

Enhancements:

· Extending the vehicle

· Rear reserve wheel (simple and cool).

Winch – Rescue Jeep

Worksheet: KH.M.48

Subject: Double power increasing transmission, ratchet lock.

Auxiliary Tools:

· Winch model.

· Sewing thread.

· Rubber bands.

Lesson Structure:

1. Story of jeep ride.

2. Explanation of the term "Winch"[footnoteRef:17]. [17: A Winch is a devise built to displace heavy loads using a cable attached to an axle. ]

3. Explanation of the term "Double power increasing transmission"[footnoteRef:18]. [18: A transmission where a small gear turns a larger one is a single power increasing transmission. When the driven gear (the big one for this transmission) is attached on the same axle to a small gear, and that one drives a large gear– we get a double power increasing transmission, since we have two small gear driving larger ones (as illustrated on worksheet). ]

4. When given two power increasing transmissions, one single and the other double, which both increase the systems force equally – go over with the students about the advantages and disadvantages of using a double power increasing transmission rather than a single one[footnoteRef:19]. [19: A single power increasing transmission can increase the exact force that a double power increasing transmission can increase. How? Simply use a small gear to drive a huge gear. A disadvantage of the single power increasing transmission is that the system must be very big since the bigger gear must be significantly larger than the small one. An advantage of using a single power increasing transmission is having only one point of friction instead of two in the double power increasing transmission.]

5. Explaining the term "Ratchet lock".

6. Construction of the model.

7. Ask a volunteer to grab the bigger wheel connected to the engine in order to stop it. After that ask them to stop the axle pointing out (external axle), the volunteer shouldn't be able to stop it because of the double power increasing transmission.

8. Enhancements.

Story:

Jeep ride (use your imagination…). One of the jeeps falls down a cliff without the passengers. A towing truck is being called. The towing truck pulls the jeep out using its winch. The towing truck has a ratchet lock that prevents the jeep from falling as it is being pulled out.

The Ratchet lock:

Note: The gear can spin left, but if it spins right it meets resistance.


Gear ratio: A large gear (40) drives a small gear (8). To an axle attached to the small gear another 40 gear is connected. The second 40 gear drives another 8 gear. How many turns will the second 8 gear make during spinning the first gear one full round? Answer: 25.

Technical explanations for construction:

· At stage 5 – remove the ratchet lock that was attached at stage 3 and displace it forward.

Enhancements:

· Build a vehicle to be pulled by the winch, as if it was rescued.

· Build an elevator that can rise from the floor to the table.

· Build a triple power increasing transmission.

Tunnel Boring Machine or Electrical Drill

Worksheet: KH.M.70

Subject: Triple power increasing transmission.

Lesson Structure:

1. Story of using an electrical drill.

2. Drawing the transmissions.

3. Riddles.


· This class has some extra time. Please ask challenging questions.

· In order to demonstrate the triple power increasing transmission, a volunteer should be asked to stop the drill by grabbing the gear attached to the engine (where they will succeed), and from the far end of the drill (where they will fail).

Story:

I received a phone call yesterday from a friend of mine who wishes to dig and find oil in Africa. My friend had contacted Kola (the seamstress) and was able to receive an oil searching license in Africa. He wishes to get instructions for building a drill from you. At this point, the drill should be drawn on the drawing board and different riddles should be told.


All three transmission systems should be drawn, and according to the class's level – questions regarding gear ratios should be asked (let’s assume that all small gears have 8 teeth, and all large gears have 40 teeth). How many times must the driving gear rotate in order for the drill to fulfill a whole rotation? Answer: 125.

In order to conclude the riddle, the following table should be drawn:

According to the table – in a quintuple (5) power increasing transmission, how many turns will we make for each system rotations? Answer: 2^5 = 32

Enhancements:

· Turn the tunnel boring machine into a drill.

· In the basic model: Use a crown gear when building the transmission so the tunnel boring machine can move.

· Build another power increasing transmission.

Lifting using Pulleys

Worksheet: KH.M.51

Subject: Saving power.

Auxiliary Tools: For the experiment: a rope, 2 pulleys with hooks attached, spring scale, weights to be lifted. For the model construction: Sewing thread, scissors.

Lesson Structure:

1. Defining 'arm', 'fulcrum' and 'load'.

2. Experiment.

3. Riddles for the engineers.

4. Construction and enhancements.

The experiment taking place:

Lifting using one pulley: see figure A.

1. Weigh the load – a LEGO bag for example (8kg for the example).

2. Tie a fixed pulley to a railing (fulcrum #1).

3. Insert the rope through the pulley.

4. Tie the rope to the LEGO bag.

5. Tie the spring scale to the counter side of the rope.

6. Pull the rope by pulling the spring scale – still 8kg.

Up to here – Figure A illustrates.

Conclusion: If I was a construction worker standing on the top of a crane, and I wanted to lift a heavy load – I would have to use a lot of force in order to lift it.

Lifting using two pulleys: see figure B.

1. Tie a fixed pulley to the right railing (fulcrum #1).

2. Insert the rope to the fixed pulley and only afterwards to the movable one.

3. Tie the counter side of the rope to the railing (fulcrum #2).

Up to here – figure B illustrates.

From this point, use figure C:

4. Tie the load to the movable pulley.

5. Lift the load (LEGO bag) and weigh it (4kg).

Conclusion: We saved half the amount of power that must be used – we lifted the load using one fulcrum only. Every fulcrum holds 4kg.

Conclusion: If I was a construction worker standing on the top of a crane, and I wanted to lift a heavy load – I would have to use only half the force in order to lift it.

BA

C


6. What would have happened if I was to lift the 8kg LEGO bag using one more pulley and one more fulcrum? Answer: I would have only used the effort needed to lift a 2kg load.

7. If so, could I add many pulleys and fulcrums and use hardly any force? The answer is that after 6 fulcrums, the friction is larger than the power we saved, so the load becomes heavier.


The difference between stage 10 and stage 14 is the ability to lift a load twice as heavy.

Enhancements:

1. It is possible to build an elevator or use any other type of weight instead of the LEGO bag.

2. It is possible to lift the poles using the affixing technique.

Balloon Car and Rocket Launching

Worksheet: KH.U.11

Subject: Newton's third law[footnoteRef:20] - "Action-Reaction law"[footnoteRef:21]. [20: Isaac Newton was a physicist and mathematician, considered as one of the world's greatest scientists of all time. His work from 1687 contained a description of the law of gravity, as well as the three laws of motion, and laid the basics for classical mechanics and modern engineering. ] [21: Action-Reaction law, known also as Newton's third law, deals with forces applied upon the interaction between bodies. This law is the last to be published in the laws of motion anthology. According to this law whenever a first body exerts a force on a second body, the second body exerts an equal and opposite force on the first body (both bodies are under no other influences by any other forces). The action and Reaction are 2 forces equal and opposite that act on different bodies, therefore they cannot cancel each other despite the fact that their sum equals to zero. Attention: two forces, equal and opposite working on the same body are never an Action and Reaction.]

Auxiliary Tools:

· For the model: balloons and candy.

· For the rocket launching: a pump, bicycle needle, cork plug, empty 1.5L bottles (preferably Coca Cola bottles).

Lesson Structure:

· Explain who Isaac Newton was.

· Explain Newton's Action-Reaction law.

· Constructing a car according to the manual.

· Compete for candy.

· Organizing the kit.

· Launching rockets in an open field outside the classroom.


The person pulling the rope tied to the wall exerts on the wall a force F1. On the person acts a force F2 which is equal and opposite in its direction.

Technical explanations for construction:

· Use a 10 axle instead of an 8 axle.

· Emphasize that at stage 2 we are using 6 beams.

Enhancements:

Avoid enhancements due to lack of time!

Rules for the competition:

The students compete between each other by seeing who can make his car go the greatest distance. Whoever reaches five winnings may have a candy.

Guidance for the rocket launching:

General: take a bottle, add a bit of water and close with the cork plug (wine corks), pierce the cork with the bicycle needle, connect the pump and quickly inflate the bottle. The result: the bottle flies .

Precise guidance for rocket launching – deviating from these instructions may lead to the breaking of the needle or the cork getting stuck permanently in the bottle:

1. Launch the rocket in an open space! The rocket should fly 20m high and an additional 15m away.

2. Fill the bottle with a small amount of water – a finger and a half widthwise (2-3cm).

3. Insert the cork with pressure – but not the whole way.Note: if inflating is hard, enter the cork in a looser manner.

4. Pierce the cork with the bicycle needle.A. Note: look for the hole carefully – do not use lots of force! Otherwise the needle will bend. B. Note: If one wishes, one can take the needle off the pump, enter it into the cork, and re-attach it to the pump in the end.

5. Place the bottle in the proper angle (approximately 60 degrees, try first outside).

6. Place the student behind the pump, and help him inflate while standing behind them (so you don’t get wet).

7. After the bottle has been launched, receive it and do the same with the next student.

Game details:

Touch (don’t grab) the bottle while it is still in air. In order to do that, divide into two groups:

Group A – sends one student each time to launch a rocket. The others observe.

Group B – Stands in front of the rocket and tries to touch it. Every time the bottle gets touched before reaching the ground – the score rises by one point.

Note: If there is not enough time, let two students launch the rocket together.

Plough

Worksheet: KH.M.56

Subject: Speed decreasing transmission, learning basic agricultural terms, using a plough.

Auxiliary Tools: Rubber bands.

Lesson Structure:

1. Ask the students – what they like to eat the most, then connect it to a growing organism, and connect it to the plough. (Example: Chocolate → Cow → grasses and legumes → plough).

2. Procedures done before sowing seed and planting:A. Plowing – turning over the upper level of soil. Purposes: - Airing roots that need oxygen in order to survive.- Bringing up organic materials, deteriorated organisms, so they can feed the new plants.B. Creating "flower beds" – digging to a certain depth in order to maintain water around the plants.C. Sowing and Planting.

3. The use of a power increasing (speed decreasing) transmission in the field.


· The student must show the instructor every stage, and the instructor must direct the student towards the parts being used on the next stage.

Enhancements:

· Making the crumbling comb wider.

· Making the plough faster (by enlarging the impeller).

· Adding a pulled cart for carrying agricultural equipment.

· Enlarging the plough and making it more massive.

Railroad Barrier

Worksheet: KH.M.54

Subject: Snail transmission.

Lesson Structure:

1. The origins of the name "snail" are three: (1) it reduces the speed, (2) it looks like a snail, (3) if you accidentally step on it, you hear a "pchkk"

2. What is a snail transmission and what are its characteristics: (1) one-directional transmission – can only impel, not vice versa. (2) Speed decreasing transmission. (3) Right angel transmission.

3. In order for the 24 gear to rotate a full rotation, the snail must rotate 24 times (each snail rotation moves one tooth on the 24 gear). Therefore, it is equivalent to a double power increasing transmission in which the small wheel is an 8 gear and the large gear is a 40 gear.


If class is weak, work in pairs.

Enhancements:

· Is the model too slow? Encourage the students to increase the speed. The easiest way is to do so is to switch between the large and small gears, on the transmission between the engine and the system.

· On the back side of the worksheet is a rising pedestrian bridge.

· Extend the barrier.

· Make the model mobile.

· Build a simple vehicle that can pass under the barrier.

Amusement Park Motored Merry-go-Round – "Chair-o-Plane"

Worksheet: KH.M.69

Subject: Centrifugal force vs. Centripetal force

Notes for the instructor: Emphasize on the blackboard suffixes "-fugal" and "-petal".

Lesson Structure:

1. Ask the students to explain by themselves the centrifugal and centripetal forces.

2. Clarify the terms - centrifugal and centripetal forces, using the "-fugal" and "-petal". Define the centrifugal force as the tendency to move from the center – outwards (draw a circle with arrows pointing from the center outwards), and the centripetal force as the force keeping objects from flying to infinity (draw a circle with arrows pointing from out of the circle towards its center).

3. Reminder of the "real incident" that occurred at the amusement park with Joseph. See below (riddle).


· Joseph was riding the Merry-go-round as the chain broke. Where will he fall? Downwards? Far? Answer: Far. Who do you think is the winner in this situation, the centrifugal or centripetal force? Answer: Centrifugal. Lucky for Joseph – he happened to land on the trampoline and nothing happened to him .

· To which angle will the Mary-go-round's arms rise? Answer: 90 degrees – a straight angle. The question is why? Answer: Because objects want to be thrown out of the circle and for larger angles there is need of a different sort of energy that is not defined as the centrifugal force.


· Use only the gray nails (not the black ones).

Enhancements:

· Making the Merry-go-round a rigid object.

· Adding more chairs with axle dividers.

· Extending the Merry-go-round's main axle, making it higher.

· Exchanging the Merry-go-round's arms (replace a 6 axle with an 8 axle).

Industrial Mixer – Preparing a cake

Worksheet: KH.M.47

Subject: Vocabulary.

Auxiliary Tools:

· Table spoon, Spatula, Bowl, Paper towels and Baking paper.

· Table spoons of Vanilla instant pudding = Number of students * (1/3).

· Mixture of cream and milk according to this formula: Cups of milk = Number of students * (1/6).Cups of cream = Number of students * (1/30).

· Lots of biscuits.

Lesson Structure:

1. Explanation of the words "Mixer", "Mixture" and "Beater".

2. Model construction.

3. Each student: mixes, licks, rinses and organizes their kit!


Opening state: Two bowls, one with a thin mixture and the other with a thick mixture. What kind of transmission should we use for each mixture? Answer: for the thick mixture we should use a small gear to rotate a larger one (power increasing transmission) because of the friction, and for the thin mixture we should use a large gear to rotate a smaller one (speed increasing transmission).


· Attention! Choking hazard of small pieces that might have fallen into the mixture.

· Wash the beaters before using them.

· Rinse the beaters after using them.

· If time is a limit, allow 3-4 students to work together.

· Send the students to rinse the beaters approximately 20-25 minutes before the lesson is over (according to the number of students).

Cake preparation technique:

1. Put mixture in the bowl.

2. Begin whipping the mixture with the students.

3. Break some of the biscuits in the bowl (brake, do not crumble).

4. Continue whipping.

5. Stretch out the baking paper, and lay biscuits on it – one biscuit for each student.

6. Spread the mixture on the biscuits.

7. Add another layer of biscuits.

** Biscuits should be lightly soaked before using them.

Enhancements:

· Place the mixer upright and turn it into a table mixer.

· Join one of the students and construct a "Mega-Mixer", one that can beat several mixtures simultaneously:

Applauding / Flying Man

Worksheet: KH.M.26

Subject: Aviation history, transmitting circular motion into linear motion.

Auxiliary Tools: Rubber bands, four folding 2 beams.

Number of kits: One + 4 line.

Lesson Structure:

1. Brief Explanation of the history of aviation and Leonardo Da-Vinci.

2. Link between the applauding man and the bird's wings.

3. Brief explanation of the Wright brothers.

4. Review the transition from circular motion to linear motion.

5. Review the different types of transmissions.


1. Attention! Construct in pairs according to the colors. When yellow stages are over, the student should help his partner work on the white stages.

2. The rubber band on the man's face is crucial for the machines operation.

3. At stage 2 – note that there are 2 pulleys attached to the engine.

4. At stage 3 – note the half bush between the beam and the steering wheel. Moreover, the axle should stick out from the rear side only, and not from the inner side.


The tower that was built on stage 1 is hiding in stage 2. A common mistake is to take the tower apart and move it to the base's side!


The longer the man's hands are – the steadier his face will be.

Enhancements:

· Pilot's face.

· Arm extension.

Aviation history:

People have always aimed to imitate birds and fly freely in the sky, yet the construction of a usable aircraft has only recently become possible. The first man to have designed a useful aircraft is Leonardo Da-Vinci, who designed the first glider in the 15th century and a helicopter-like aircraft as well. As with many other of his inventions, Da-Vinci had never implemented his own designs, which were only implemented in the 20th century after many other aircrafts have been constructed. The glider he designed flew successfully, but his helicopter would not take off.

Leonardo Da-Vinci: 1452-1519

Da-Vinci was a Renaissance Italian polymath, and is widely considered to be one of the greatest painters of all time and perhaps the most diversely talented person ever to have lived.

Throughout his life, Da-Vinci has been considered to be an exceptional painter, sculptor, architect, musician, scientist, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist and writer whose genius, perhaps more than that of any other figure, epitomized the Renaissance humanist ideal, A man of "unquenchable curiosity" and "feverishly inventive imagination".

Aviation according to Da-Vinci:

The passion to fly is realized throughout his research and illustrations he had left behind. From a young age he was enchanted by flying, and studied birds’ flight. Sketches have been found of aircrafts designed with bat-like wings. The majority of his work on the subject was done in 1505, and gathered into the Turino codex, where he had studied birds and bats systematically, and designed several "Bird-Aircrafts". These "Aircrafts" included machines in which the pilot would lie down with mechanical wings strapped to his back – of which he would operate using pedals and handles, or aircrafts in which the pi

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