Blog Update

Today Mr. Ward went over the equations needed for the assesment, which was good to be refreshed on. I started the lesson by going into the workshop and weighing my kart and giving it one last run.
The average for my kart is about 2.7seconds, though my best was 2.465. Afterwards I went back into the classroom and did the rest of my calculations and added them to my assesment. I also got my progress pictures from my blog and put them onto my assessment to hand in.

I will print my assessment tonight

Kart before last lesson. Photos uploaded

Blog update

Today was purely racing. It started off really good. A time of 2.65!! But then I added a price of plastic at the front to supposidally reduce the air resistance but I resulted in increasing the time by .4 of a second.
I have also noticed that the front wheels aren't fully connecting with the track and are sometimes spinning

Blog Update

Today I finished my kart. I glued the switch on and front wheels and with a push, the kart stayed on a straight course. I soldered the wires together, this time I was more successful doing it myself. I then glued the copper wires onto the front and end of the kart.

Then it was time to give the kart a test run, I put a little grease on the copper wires, in order to reduce friction between the wires and the fishing line. On my first run of the kart, it didn't time, but it looked faster than I expected so I was excitied. When I tested it for a second time, I got the time
= 2.795 seconds!

Under 3 seconds on my first run!!! After, I discussed with Mr. Ward why we think that having the motor on the bottom imporves the time. I thought it was a simple matter of just reducing the air resistance and adding weight to the wheels (so they do not spin). But Mr. Ward had a good theory in that, having it on the bottom actually pushes away from the axel and therefore reduces the friction.

I believe ways in which i can make my kart go faster is to

• grease between the gears and wheel joints
• add a peice of plastic on the front to the top of the battery to reduce air resistance
• sand the wheels

I will also need to measure the track and weigh my kart in order to get the data needed to finish my handed in assessment.

I am slowly reducing the amount of writing I have for my assesment. I have taken out all example non-relevant to the brief (even though there are more cases of friction than what effects the brief) and I am trying to reduce the materials list. 

Assignment update

This is my assignment so far. I am having extreme diffuculity keeping ti under the word limit and I have not even done my reflections

Mr. Ward        Week 7 2012

Amanda Tauber

Investigate and Designing

Friction:

Friction is a resistant force and occurs when any two objects (solid, liquid or gas) come into contact with each other. If an object is going one way – friction is pulling the object in the other direction.

Friction can occur between any of the following;

·       Two solid objects – the wheels of the kart and the surface of the track, the gear kogs, the cooper wire and the fishing line, the wire holding the tires together and the plastic tube etc.

·       Solid and Air – (Also known as air resistance), this can occur anywhere in the direction the kart is travelling, when the kart pushes forward, the air resistance will be pushing back on it.

·       Solid and Liquid – not as relevant to this design brief but an example of this could be a person waddling in the water

·       Liquid and Air – once again, not as relevant to this brief, but you notice this type of friction when water falls over a waterfall and is turned into spray due to the friction with the air.

Friction is useful for;

·       Grip –the purposeful friction made into the wheels in order for them to have grip on the floor. This stops the tires from spinning. But in everyday uses, it is used in most items designed to move and stop – anything from motorbikes to the grip on shoes.

·       Positive Air resistance – though not entirely relevant to this experiment, parachutes and similar inventions use air resistance to work (to catch the air, allowing the rider to ‘float’)

·       Brakes – though our kart will not come with brakes, friction is used to slow down and stop transport vehicles, (cars, motorbikes, trains etc. ) by applying pressure (in simplest form) to the wheel which thus causes the form of transport to slow down and stop.

Friction is a problem when;

·       The wear between surfaces causes machernery to wear away and need replacement

·       Friction/air resistance/drag is a waste of energy in machines for it has to create a stronger force to counter the friction pushing back on it.

o   Also slows down moving objects

Ways to reduce friction;

·       Lubricating oil and grease between surfaces

·       Wheels or ball bearings or polystyrene balls to roll the surfaces past each other

·       Cushions of air (as in hovercrafts for they avoid the friction with the ground)

·       Streamlined shapes to keep air resistance at a minimum.

Velocity:

Velocity is the speed in which an object is moving in relevance to the objective destination. Unlike speed which describes how fast the object is moving, velocity gives a value on how fast the object is going from point ‘a’ to point ‘b’

e.g. a car driving 50km/hr north.

A constant velocity must include a constant speed and constant direction (straight path). Eg. A car is at a constant speed of 40km/hr and is moving on a straight road – hence it has a constant velocity

The velocity of an object will accelerate or decelerate not only when the speed of the object changes, but if the direction varies. I.e. if a car is turning a corner but, still is at a speed of 30km/hr the velocity decelerates and then accelerates because the time it takes to get closer to the objective goal varies as the car goes off the direct course.

Velocity is calculated by the equation, change in distance over change in time. Or written as;

The velocity of my kart is;

Distance =

Time =

Therefore,

V = _/_

 =

Kinetic Energy is the energy of motion, any object that moves contains some amount of kinetic energy. Kinetic energy is expressed by the equation: KE = ½ x m x v² . This shows that the value of kinetic energy relies on the mass and velocity (or speed) of the object.

Acceleration - Perform calculations to determine the average acceleration of your vehicle.

Materials	Use	Characteristics	Properties
Plywood	The ‘chassy’ of my design. It keeps all the other materials used to power my kart secure.	Very light weigh however it is not ‘flimsy’ and does not break easily. With a power saw, it is easy to c	Approximently 4mm thick, 11cm long and a varing width of 4cm – 0.1cm.
Small gear	Attached to the motor, it interlocks with the larger motor, thus, transferring the electrical energy within the motor into kinetic energy; spinning the wheels.	It is made up of a plastic and the cog has a small hole through the center of it. This hole is a ‘push fit’ insuring that it is attracted to the motor.	It has 8 indents which interlock with the larger wheel and an approximate 0.3cm diameter.
Large Gear	Attached to the back Axel, this large gear. Interlocking with the smaller gear, this large gear turns the wheel.	“as above”
Motor with +ive and –ve wires	To covert the electrical energy into kinetic energy	It is make of metal with a plastic cap on one end of the motor.	Has a metal point that the small cog is attached to. Also has coloured positive and negative wires, pre soldered to the opposite end.
X2 Large wheels	To transfer the kinetic energy from the motor and use that energy to drive the kart forward	A circular diameter with the grip and tire cap removed. Has an opening on the inner side. Alowing the axel to press fit – so it does not slide off.	The tire came with a cap and grip tire, but I had removed them.
x2 small wheels	To move the kart across the track.
x2 strands of copper wire	To keep the kart running along the track in a straight line	The copper wire is dutile, allowing it to be bend and manipulate into different shapes and forms	It only consists of the copper wire
Battery Pac with +ive and –ve wires	To transfer the chemical energy through to electrical energy	Normal characteristics of a x2 battery pac	The battery pac and a positive and negative wire.
x1 Switch with +ive and –ve wires	To have easy access to open and close the circuit.	A flick switch.	has coloured positive and negative wires, pre soldered to the opposite end.
x2 4cm plastic tube	To attach the axel to the chassy whilst allowing the axel to spin	A hollow plastic cylinder	transparency, flexibility, elasticity, permeability, water resistant, electrical resistance
x1 7.2 (approx.) axel	To attach each of the two wheels together and to enable the gear to successfully turn the wheel.	Metal cylinder	It is hard, ensuring it does not bend easily

Planning – A documented series of ideas showing the development of your final solution.

Sequencing – This is for my final design (using plywood)

1.     Making the Chassy

a.     Draw the chassy (expressed in image *final* as shown above in planning) with correct measurements and all lines shown, adding 2mm to each side.

b.    Using the “jigger jagger” cut the shape of the chassy out.

c.     Sand all sides of the chassy until smooth. Sand also the front point of the chassy, allowing a smooth rise from the bottom to the top of the chassy.

2.     Producing the Front Wheels

a.     Measure and cut the plastic tube and axel to scale. (note. When cutting the plastic tube, use pliers to reopen the end of the tube that was closed via the cutting of the tube)

b.    Remove the wheel caps from the small wheels

c.     Hammer one point of the axel into the first of the small wheels, slide the plastic tube onto the axel.

d.    Hammer the final small wheel onto the end. (make sure you leave enough room between the plastic tube and wheels to ensure that the wheels spin)

e.     Leave for later

3.     Producing the Back wheels,

a.     Follow steps 2a-c with back wheel measurements

b.    Hammer the large gear on (top hat first). Using a cog on the side of the workbench and hammering the axel through the gap.

c.     Hammer the other wheel onto the end of the axel

4.     Using hot glue, attach the battery pack to the very end of the chassy, with both wire’s facing the end of the chassy.

5.     Attaching the wheels

a.     Glue both sets of wheels on by applying a line of hot glue over the lines ruled onto the chassy as done in step 1a, and attach the white plastic tube to the hot glue.

b.    Allow to set before gluing the other wheel

6.     Attaching the motor

a.     Apply hot glue to the bottom of the motor

b.    Press the motor onto the bottom of the chassy and slide the motor until the small gear wheel interlocks with the large gear wheel

7.     Hot glue the switch to the back of the chassy.

8.     Wiring up the elements

a.     Using the wire cutters, cut the wires to a length in which the least wire is hanging loose

b.    Using the soldering iron heat up the connection points between the two wires, once hot, melt some _____ onto the connection

c.     Repeat for all links

Production Images (from Blog)

30th July
13th august

Evaluate

Aspects of Design – Function. Based on your calculations critically evaluate your vehicle’s performance and comment on the effectiveness of your solution? What is not good or in need of attention with regard to your solution?

Future improvements – State any improvements that could be made if you had the opportunity to redesign the solution i.e. ways to further eliminate friction and resistance forces.

Other vehicles: Comment on the successes and / or failures of other vehicles.

Blog update

Today we could not go into the Workshop because Mr Ward wasn't there. This was a bit of a nusence because this lesson I had planned to finish my kart so that the next lesson I can collect my data. I guess I will have to work very quickly tomorrow and attempt to get it all done for next week.

So I just continued working on my assessment and I have finding great difficulty keeping it at 500 words and I haven't even finished it yet.

Problems, problems, time and problems is in summary what I am reflecting on this blog

Blog update

Today I went on with my new design. As planned at home I had the battery PAC on the top, motor at the bottom as with the switch. I had To pik off the hot glue from my previous design and trim the plastic and metal a bit to ensure it fitted. However I have too much room at the front of the vehicle so I will have to try and sand as much if that off because everything else is already on.

Before we started today, Mr ward talked us through his design and a really good way to present your design on the assignment sheet. It was really good to see that his design was similar for what I had planned to do. But things for me to remember to add are, liberation between points, sand the wheels, and add some sort of air resistance illimantor to the front so that the air does by push to far back on the vehicle.

Blog Update

Today in DF I started over. I made a new kart this time out of ply-wood because the foam was too flimsy and when I took it out of the cupboard today it broke. I have made a similar design, and though it was a bit harder to sand in a way that the mass of the kart at the front slowly built up, I did it. This is to reduce friction. I have found that working with the ply-wood is much easier to draw the lines on it, in order for the wheels to angle up properly. I took the tires from my old design and began hammering them down when it was time to pack up. 

I believe that I'm working a lot quicker through the project know that I know and am confident with what I am doing. 

Blog update

Today in Design, i finished my kart, however it was not as successful. I had cut all my wires to size by using the wire cutters. I had the wires put up together and the kart ran straight and at a reasonable speed. However, when it came to soldering the wires together, the first two were a success but when doing the third I accidently had the soldering iron too close to the other wires and it melted the plastic and molded two other wires together. In reaction, the motor didn't turn, but by adjusting the witch slightly to a spot where the wires must have run in the correct loop, the wheels spun. 

But still it did not fix all my issues. When I clicked the switch to get the kart to race it began running in circles. I found that the right wheel was not connected to itself fully (as in the tire slipped off the wheel skeleton). I hot-glued the tire to the wheel in a trial to fix it without wasting resources. I was unable to trial if that change affected the wheels for we ran out of time. 

There is approximately two weeks left before it is due so next lesson I will work on my second design because I am finding that the foam is too delicate in which the motor, switch and batteries are falling off because they do not have a sturdy structure. I will work on my design tonight and bring in into my next class. 

Friction

I did some research on friction, and though I have too much information to submit in my final, I have decided to put what I have found and translated into my own definition and meaning, to my blog for personal reference to me when creating my design. 

Friction: Define & Examples. Research aspects of friction as related to vehicles and propose means to elimate/reduce friction when designing you vehicle.

Friction is a resistant force and occurs when any two objects (solid, liquid or gas) come into contact with each other. If an object is going one way – friction is pulling the object in the other direction.

Friction can occur between any of the following;

·       Two solid objects – the wheels of the kart and the surface of the track, the gear kogs, the cooper wire and the fishing line, the wire holding the tires together and the plastic tube etc.

·       Solid and Air – (Also known as air resistance), this can occur anywhere in the direction the kart is travelling, when the kart pushes forward, the air resistance will be pushing back on it.

·       Solid and Liquid – not as relevant to this design brief but an example of this could be a person waddling in the water

·       Liquid and Air – once again, not as relevant to this brief, but you notice this type of friction when water falls over a waterfall and is turned into spray due to the friction with the air.

Friction is useful for;

·       Grip –the purposeful friction made into the wheels in order for them to have grip on the floor. This stops the tires from spinning. But in everyday uses, it is used in most items designed to move and stop – anything from motorbikes to the grip on shoes.

·       Positive Air resistance – though not entirely relevant to this experiment, parachutes and similar inventions use air resistance to work (to catch the air, allowing the rider to ‘float’)

·       Brakes – though our kart will not come with brakes, friction is used to slow down and stop transport vehicles, (cars, motorbikes, trains etc. ) by applying pressure (in simplest form) to the wheel which thus causes the form of transport to slow down and stop.

Friction is a problem when;

·       The wear between surfaces causes machernery to wear away and need replacement

·       Friction/air resistance/drag is a waste of energy in machines for it has to create a stronger force to counter the friction pushing back on it.

o   Also slows down moving objects

Ways to reduce friction;

·       Lubricating oil and grease between surfaces

·       Wheels or ball bearings or polystyrene balls to roll the surfaces past each other

·       Cushions of air (as in hovercrafts for they avoid the friction with the ground)

·       Streamlined shapes to keep air resistance at a minimum.

                                                                 

·       All friction is not all bad

·       E.g. brakes – it is the friction between the brakes and the wheels, which cause the thing to stop.

·       Water, oil and other forms of lubricants reduce friction

Blog

Today Mr Ward said that if we got our kart under 3 second, that would be really good. Even though the record in 2.4 seconds. Today I adjusted my kart from the errors i noticed yesterday. I opened the endings of my plastic tubes more to allow it to spin properly, I also changed the wheels because I had adjusted it so much that they were no longer a tight fit. I also straightened up the back wheels to make them more parallel.

Next lesson I will wire up (using the soldering iron) and test it to see how fast it is capable of going and either make further improvements from then or start a new design using ply-wood.