Windsurf Hydrofoil Design Project - Gcse 2o6x5c

Hydrofoil Fin for a Windsurfing Board GCSE Project

Ollie Martin

Centre number :

63433

Candidate Number:

6310

Content Page

Ollie Martin

Objective 1. • Task analysis • Writing a design brief

Objective 2 •Investigating existing products •Writing a specification •Planning and research •Questionnaires

Objective 3 •Generating ideas

Objective 4 •Developing the best ideas •Manufacturing specification

Objective 5 •Schedule for manufacture •Manufacturing

Objective 6 •Evaluation and testing

Ollie Martin

Hydrofoil Fin

Centre No:63433

Candidate No:6310

Page: 0

Objective 1 •Writing a Design Brief •Task Analysis

Design brief I have been windsurfing for the past few years and always wanted to travel faster. I have seen Moths (a performance racing sailing dingy) , some having hydrofoils, enabling them to travel at great speeds in both light and strong wind conditions on the reservoir where I windsurf. I was so inspired by the performance that a hydrofoil could produce, that I researched to see if a hydrofoil could be fitted to a windsurf board. The content that I found on the internet was limiting but I was able to find a video clip on YouTube, www.youtube.com/watch?v=1oyWMusaDTI. It showed a man sailing two feet above the water and travelling at a great speed. It looked like he was flying! It was far more exciting than the normal windsurfing video clips. It inspired me to make a hydrofoil for my windsurfing board. The product is intended for windsurfers looking for an extra dimension. However I am aware that the product must be affordable. It is a relatively new area of marine engineering with lots of room for experiment. The timescale is to complete the project by the end of the Lent Term of 2009. I am studying the full course GCSE Resistant Materials for OCR. There are three recognized types of foils: T foil, V foil, ladder foil. The most common style is the T foil therefore I have decided to develop this type only because my timescale is limited. To be successful with this project it is essential that I fully understand the theory and laws of hydrofoils as their performance is very dependant on the exact angles and profiles used, in order to create the perfect and most efficient lift.

The Reasons for Producing a T foil: •Unable to buy product in the UK . •Inspired to try it out after seeing videos on YouTube. •To be able to go faster windsurfing. •To be part of a new growing hydro-board generation. On page 2 is a bubble diagram of my design brief.

Ollie Martin

Hydrofoil Fin

Centre No:63433

Candidate No:6310

Page:1

Ollie Martin

Parents’ budget Watch video on: www.youtube.com/watch?v=1oyWMusaDTI inspired me to make one to be able to travel faster

Material costs One year

Time

Constraints

Lack of Information -as it is a new concept

Videos

Ollie Martin

Windsurfing

Interests

Manufacture

All genders

Problems

Target market

Windsurfers Compatible to all board fitting

Custom made designs

Imagery Themes Styles

Colours

V foil

Ladder foil

Hydrofoil Fin

Existing products

Materials

Fibreglass

Ollie Martin

Enough information

Hydrofoil fin

All ages

Understanding theory

Carbon fibre

Aluminium

There are boards made by Rush Randle which retail for $2,495 these are boards with fins permanently attached. Unable to buy a single hydrofoil fin for windsurfers commercially, although I am aware that there are foils available for kite boards.

Kevlar

T foil

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Candidate No:6310

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G10

Objective 2 •Planning the Research •Questionnaire •Researching Existing Products

•Design Specification

Fins

Board shapes

Research : Planning

Equipment

Ollie Martin Marine engineers

Wind surfing Pro windsurfers

Emails

Designers Shops

Interviews

Windsurfers

Designers

Primary

Methods of research

Secondary

Questionnaire

Personal experience

Videos

Research sources

Observation At events/shows

Sailing and Windsurfing

Magazines

Books

“Boards” “Windsurf” “Board Seeker” Other magazines Hydrofoil theory Sailing Hydrofoils

Ollie Martin

Hydrofoil Fin

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Websites

Articles

Brands “the hydrofoil society” forums/blogs/enthusiast

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Sailing Club

1)

- Can you windsurf?

Yes / no

1)

- For how many years have you been windsurfing ? ……Years

1)

-What age are you ? Circle answer. < 10

1)

-How many times do you windsurf per year? Circle answer.

<5

1)

What do you most enjoy about windsurfing?

Speed sailing / Racing / Freestyle / Free ride/ Others.

1)

- In what wind speed do you windsurf?

1)

- Which two colours do you prefer ?

1)

- Are the waves a problem for you?

1)

- Have you ever tried windsurfing with a hydrofoil? Circle answer.

1)

- How much would you pay for a hydrofoil fin? £…… to £…….

1)

- What would be the 3 must haves of a hydrofoil windsurf in the list below? Please put a X in front of the selected items.

11 > 19

20 > 29

Research : Questionnaire

Ollie Martin

30+ 5-15

15-25

>25

….. Knots to …. Knots

Yes / no Yes / no

___ Good stability ___ Good manoeuvrability ___ Elevation of 2 feet ___ Elevation of 3 feet ___ Elevation of 4 feet ___ High speed ___ Allow jumping ___ Good appearance ___ Low speed take-off ___ Adjustable take-off speeds ___ Low weight ___ Others ………………………………………………….

Ollie Martin

Hydrofoil Fin

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Candidate No:6310

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The data I received from the questionnaire showed me the ability level of the windsurfer that was interviewed. The product should be designed so that it is suitable for this level.

Analysis of Questionnaire Ollie Martin

Wind speed (knots) <5 knot 8

5 - 10 knots 1

10-15 knots 15 - 20 knots 3 2

20 knots > 2

The sample of windsurfers were aged from 11- 19 with an average of 3 years of windsurfing experience. They were all able to sail in less than 5 knots of wind but only 2 were able to sail in more than 20 knots . So the range for the product use should be between 1 knot to 20 knots. The majority were into racing . So the product should take into consideration what a racer would like.

Ollie Martin

Hydrofoil Fin

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Analysis of Questionnaire Ollie Martin

My product is aimed at windsurfers, therefore, I have only interviewed windsurfers, as non windsurfers would not add anything to my research. From the research I have concluded that the windsurf market wants :

My product should be made from carbon fibre and fibre glass composite as this is lightweight but a durable material.

On the whole waves are not a problem for this level of windsurfer, so the design needs to be able to cope with the force of waves and maintain a degree of stability.

The key features in my design are that it must have; a good stability; high speed ability; allow jumping and an attractive appearance.

£0

Hydrofoil windsurfing is a new concept which few people have tried. So it is hard to get advice.

Ollie Martin

Hydrofoil Fin

£ 50

£ 100

£ 200

£ 300

£ 400

£ 500

1 2 5 3 1 3 1 These are the retail prices for my product, from my questionnaire. I have a large range of price, with most expensive being £500 and cheapest being for free , but the most popular price was between £100 to £200.

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The most popular two colours were yellow and black, so I will use yellow and black as my finish coat.

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Rush Randle an extreme water sportsman using a foil board that he designed . See below.

Research: Existing Hydrofoil Applications 1

Ollie Martin

Hydrofoil for a Kite surfing board.

A Rush foil board worth $2,495.

International Moth - a specialist racing dingy class across the world with hydrofoils. Video off YouTube www.youtube.com/watch? v=1oyWMusaDTI

Richard Miller designer of fast acceleration and a smooth riding hydrofoil in 1980s.

Other board sports (kitesurfing) using hydrofoil fin to rise up and creating a more extreme sport.

Ollie Martin

An example showing the Speed difference with hydro foil As windsurfer has a larger sail and less weight compared to the moth

First Hobbie trifoiler, which is a type of trimaran using hydrofoil technology. Hobbie are a specialist sailing dingy company.

Hydrofoil Fin

First versions of hydrofoil surfboard invented in Hawaii , to catch bigger waves ,needs to be travelling faster to catch them. So the idea was to use a hydrofoil. They were dragged by powerboats to get enough speed to catch the wave.

Shape of enhanced hydrofoil moths hull.

An example of one of the 1st windsurf hydrofoil in the 1970s. Using a foil on the dagger board.

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Early version design of a hydrofoil on a motor boat which set a world speed record of 70.85 miles per hour in 1919 .

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Research: existing Hydrofoil Applications 2 Even nature uses hydrofoils. Sharks uses them to create lift and help them to jump out of the water.

A photo of the Speed sailing l'hydroptère travelling at 45 knots. A 18.28 metre catamaran designed to travel at speed ,with 5.7 metre long hydrofoils. It is based in the south of . I have visited this and have seen it in action!

A board designer AHD first hydrofoil windsurfing board in 2004 to be commercially made.

Front on angle showing the rise of the ship with the hydrofoil. Showing the strength of the hydrofoil being able to lift up something so heavy.

Ollie Martin

A close up shot of the hydrofoil fin on an AHD board, it has foil at front and stabiliser at back.

Hydrofoil Water Scooter Modern water sports gadget using the technology

Commercial use of the hydrofoil in the USA navy ( 57 tonne patrol gunship), greater speeds and greater fuel efficiently

Hydrofoil Fin

Ollie Martin

Use of hydrofoil in other water sports. This hydrofoil represents human force able to generate a enough power to lift it up.

Hydrofoil jet bike . Is used to increase the speed of jet bike and increase handling enabling sharper turns.

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Commercial use of the hydrofoil on the British channel crossing. The crossing time takes 50mins! The hydrofoil is designed by Boeing jetfoils. These foils are strong enough to lift a 8o tonne ferry.

An amphibious car which uses a hydrofoil to float. To new modern designs combined.

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Foil on outboard designed to create less drag therefore more fuel efficient.

Conventional Airfoils low camber-low drag-high speed-thin wing section suitable for race planes, fighters, interceptors

Research: on shape of the foil Ollie Martin

deep camber-high lift-low speed-thick wing section suitable for transporters,freighters,bombers

deep camber-high lift-low speed-thin wing section suitable for light weight aircraft Side on view of a foil deep camber-low lift-high drag-reflex trailing edge wing section very little movement of centre of pressure, good stability

AERO/HYDRODYNAMIC TESTING Produced by Dr. W. H. Mason. From his testing he has produced the most efficient shape for a foil.

symmetrical (cambered top and bottom) wing sections. suitable for stability

GA(W)-1 airfoil-thicker for better structure and lower weightgood stall characteristics-camber is maintained farther rearward which increases lifting capability over more of the airfoil and decreases drags

Ollie Martin

Hydrofoil Fin

This is Air Chair’s new water-ski design, which claims to be a“design that virtually eliminates foil wobble”

The different shapes of a hydrofoil depending on the performance needed. From stability for a beginner to technical style shape for pro’s wanting to get maximum carve and acceleration of speed. These hydrofoils are all designed for water-skis by a company called “Air Chair Australia”.

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All these fins are made using a G-10 construction which is extremely tough and hard to damage. The prices of these fins vary from £30 - £115. They are all designed for windsurf boards, but there are different fins for different needs - longer fins are for stability and shorter fins are for manoeuvrability. The wind strength also effects the length: high wind-short fin low wind- long fin

Research: fins

Racing fins

Others fins

33cm driver fin

40cm

Ollie Martin

36cm

35cm all made of g-10

Wave and freestyle fins

23 cm

Ollie Martin

40cm

52cm

Slalom fin

24cm

Hydrofoil Fin

Come in sizes from 26 – 54 cm

19cm

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Interview: Aardvark Technologies

Ollie Martin

Aardvark manufacture moth dingy that use hydrofoil technology. Following discussions with Mike Cooke ( owner of Aardvark) I gathered the following information: Surfboard shape foils: Carafino shape short and fat with large surface area for lift. Good for tricks but not very stable. Materials: :Wiz ,Matrix composites, Bristol New Materials :Peal ply to remove air Resins: Epoxy resin The moth that I saw at the reservoir which was the first Reinforcements: Carbon fibre, glass fibre time I heard about his company from this logo Moth: foils cost £700 each, of which £230 is material costs Foils are 1 metre in width at the base Modifications: need to add plate to spread force around the fin box. Bottom of foils wants a curve. Takes him 15 hours to build one hydrofoil. Safety issues: Carbon dust particles are fine. Resins are toxic. Advice/methods: surface finish important, needs to be sanded down to 800 grit then primed before painted. Split the foils into to L shapes then glue together with epoxy. Vacuum bagging Do not make angle of attack more than 4* best 4-3* The fin wants to be the strong with minimum of 6 layers of glass fibre.

A hydrofoil fin for a moth being coated in carbon fibre

Resources of information: www.nasg.com, Gurit, Rhino cad cam software. Shop in Weston-super -mare called UFO has a hydrofoil kite board

Mike Cooke The designer and a Moth builder.

Ollie Martin

Hydrofoil Fin

A mould for a fin

Scraps of Corecell PVC foam

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Peal ply

Candidate No:6310

Final product for a moth, it has a rudder foil and centre board foil

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Interview : UFO Ollie Martin UFO shop in Weston-Super-Mare specialises in kite sports including kite surfing.

Height: 84cm

The Carafino design Hydrofoil kiteboard has a short fat area used to get foil planning quickly as compared to a windsurf board. There is not much volume in a kite board so it sinks with the force of gravity from your body. This hydro board costs £800 Designed by www.Carafino.uk.co

Ollie Martin

Hydrofoil Fin

Dimensions: length of 69cm total First one 28cm second one 13cm 1st front foil optimum width 42cm 2nd back foil optimum width 33cm Fin Height 84cm

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The foil and board are attached by 4 screws on a plate. This will cope with the forces of drag and lift.

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Research : Resins

Ollie Martin

From Mike Cooke I was given the of Wiz who owns MCMC which is based in Matrix Composite Materials Company Ltd Unit E Paintworks 277 Bath Road Bristol BS4 3EH He is a marine engineer and naval architect who has been building a 30ft performance racing boat which he designed. He has also built hydrofoils for ocean racing boats. With his experience he was able to help me to make the choice of what quantities and types of resins, reinforcement fabrics and hardeners to use for the project with my budget. I decided to use SR 5550 - epoxy resin 1.00 kg, which has great properties for marine composites for example bonding “Excellent for bonding reinforcement materials such as Glass or Carbon onto wood...” Suitable for room temperature applications, gives a high gloss finish, a low surface pollution and is UV stable. This wood epoxy system has a low toxicity (Phenol and amine free). SD 5505 - Hardener 0.29 kg. They have a fast reactivity , can easily be stored and do not need to be heated above room temperature. They are used in a 3 :1 volume ratio of Resin :Epoxy

Ollie Martin

Hydrofoil Fin

Centre No:63433

Candidate No:6310

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Interview: Fabric Reinforcement and other Materials

Uni-directional Carbon fibre with glass fibre. Gives vertical or horizontal strength depending on which way is laid out. Fibres are running at 0°. This the cheapest fabric with carbon.

Bi-directional Carbon fibre gives you horizontal and vertical strength. It is a good material for the fin. Fibres are running at 0°/90°. Second most expensive.

Aluminium: its lightweight, durable, and can be ed by riveting, bolting or Techno welding.

Ollie Martin

Hydrofoil Fin

Multi directional Carbon fibre is strong in all directions, horizontal, vertical and diagonal. It is used to make the hulls of high performance racing boats e.g. Moths. With fibres running at ±45°, 0°/±45°, 90°/±45°. 0°/90°/±45°. Most expensive.

Glass fibre: this is the cheapest option but has the weakest properties compared to the others but the properties are still high.

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Ollie Martin

Candidate No:6310

Kevlar- has high tensile strength , light weight but UV damages the fibres. Middle range of price.

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Research : Materials for the profiles Properties needed: •Floats •Lightweight •Durable •Easy to shape • Resistant to water •Does not react with salt or fresh water • Does not react with resins and glass fibre Material

Properties

Ollie Martin

Image

Polystyrene

Styrofoam – is expanded polystyrene - buoyant, resists moisture. Density (10-40 kg/m3)

Pvc Foam (Corecell)

Strong and durable, light weight, easy to shape , resistant to liquids

Polyethylene Good buoyancy , resistant to liquids and has a density 0.77 kg/ m3

Ollie Martin

Hydrofoil Fin

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Research :Materials for the Profile Corecell™ PVC foam (pictured above) .

Ollie Martin

Corecell™

Benefits (as found in a corecell brochure) for using Corecell as the material for the profile: “Tough Exceptional resistance to impact, dynamic loading and fatigue. Simple Easy to use, resistant to handling damage and easy to machine. Stable Unaffected by water and highly resistant to fuel oil and hydraulic fluid. Reliable Minimal density variation ensures predictable laminate strength. Infusion optimized Available in all common infusion formats. Special knife cut Corecell infuses quickly and uses up to 50% less resin than other foam cores. Infusion ready Complete Corecell infusion technical package from concept through to testing of completed laminate. No out gassing problems Corecell does not suffer from the problems of laminate out gassing or the associated cure inhibition. Compatible Suitable for use with all polyester, vinyl ester and epoxy resins Highly thermoform able Corecell has exceptional thermoforming characteristics”

Retailer : Gurit (UK) St Cross Business Park Newport, Isle of Wight United Kingdom PO30 5WU T +44 (0) 1983 828 000 F +44 (0) 1983 828 100 E [email protected] W www.gurit.com

The disadvantages of corecell are the cost and the ease to machine with a cnc router . For these reasons I used Styrofoam instead.

Ollie Martin

Hydrofoil Fin

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Leading edge

Trailing edge

Upper Camber Lower Camber

Scientific Principles of the hydrofoil

Chord Length IMPORTANT LAW; “Fluids

Ollie Martin

pressure is inversely proportional to its velocity”

The hydrofoil creates lift in two ways. Firstly, because the fluid travels faster over the upper camber because of its curved shape which means that there is a greater surface area, therefore there is a greater distances for the fluid to travel which reduces it pressure. The fluid travels slower along the lower camber and so a pressure difference is created which causes upward lift. Secondly the angle of the foil will effect the amount of lift created . Low Pressure as less water molecules. The lift is created in two way: •The profile of the Foil. •The Angle of attack.

Flow of water

Angle of Attack

Colours combination High pressure as more water molecules ( upward lift).

Chelsea football clubs away kit. Football kit is now designed in a fashionable target market. So if a big English football clubs is choosing these colours they must be appealing.

Ollie Martin

These are tapes for clubbers to wear at night to make them visible and attract attention in the clubs. It trendy with the black of night.

Hydrofoil Fin

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Colour combination of the design will be fluorescent yellow with dark black. These colour will attract attention to this new concept. Also add a style to the project.

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Design Specification

Timescale:

completed by Lent Term 2009

Function:

to enable me to travel faster whilst windsurfing by creating a lift out of the water.

Performance:

to create sufficient lift which puts the forces on a smaller area enabling greater speed. It will be used on water e.g. sea, reservoirs , lakes.

Target market:

windsurfers of all ages, and all genders looking to travel faster in a new developing sport .

Aesthetics:

it will be a T foil shape, and painted yellow and black.

Ergonomics:

the design will encourage people to windsurf and enable windsurfers to travel faster and have a feeling of flying above the water.

Materials:

the product will be made of composite materials that are strong, light weight, do not rust and easy to shape.

Manufacture/quantity:

the foam profile will be produced by a cnc machine then sheathed in epoxy and reinforcement fibres and will be a one-off production.

Reliability:

the physics need to be correct which can be done by research and testing. If this works it will work forever as long as the angle of attack and profile remain the same.

Life in service: Cost:

Ollie Martin

it is intend to last for 3 years without any modifications. the budget is £75 to make and the product will be sold for £150. It is difficult to estimate breakeven point as other cost are not clear at this stage like marketing; light, power, workshop etc

Weight:

the product has to be as light weight as possible, but the budget might restrict this meaning fibreglass has to be used.

Safety:

glass fibre is dangerous for your respiratory system. The product may not have sharp edges as this could cut or injure fellow windsurfers or swimmers in the water.

Quality:

the product will be built to the highest quality as profiles must be perfect for best lift.

Ollie Martin

Hydrofoil Fin

Centre No:63433

Candidate No:6310

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Objective 3 •Generating Ideas

Shape of profiles

Design Ideas:

low camber-low drag-high speed-thin wing section suitable for race planes, fighters, interceptors

deep camber-high lift-low speed-thick wing section suitable for transporters, freighters, bombers

FIN

deep camber-high lift-low speed-thin wing section suitable for light weight aircraft

Ollie Martin A number of design proposals have been considered , including ladder foils, V foils and T foils. The T foil was selected because it was the easiest and most cost effective to manufacture . These reasons are why it has been developed the most out of the 3 designs. Having selected a T foil ,a range of foil profiles and angles of attack were considered.

deep camber-low lift-high drag-reflex trailing edge wing section very little movement of centre of pressure, good stability

symmetrical (cambered top and bottom) wing sections. suitable for stability

The foil design wants to optimise lift to drag ratio , which is 25:1. The angle of attack may not be greater than 15°, after this it will begin to stall. The most efficient angle of attack is 3° to 4°. This is a front on view of the T foil. The white section is the lifting section.

GA(W)-1 airfoil-thicker for better structure and lower weightgood stall characteristics-camber is maintained farther rearward which increases lifting capability over more of the airfoil and decreases drags

Ollie Martin

Hydrofoil Fin

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Shape of Front on View

Design Ideas: for fin

Ollie Martin

Planning the vertical shape of the fin

Number of Foils

The shape of the fin has to take in to strength, safety , drag and manufacture. The fin needs to be strong as it is holding all the force from the foil. The product needs to be as safe as possible so sharp edges need be at a minimum as this is a water sport which will have other water s and to protect marine wild life.

Super light winds

Shape of Fins

Heavy winds

The number of foils on the fin was considered to make the product compatible to different wind strength's. A single foil was selected for the following reasons : •Cost to manufacture •Sufficient lift can be generated from one foil.

The above sketches helped form the design ideas for the fin.

Ollie Martin

Hydrofoil Fin

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Design ideas for shape of fin

1.

2.

Based on a basic fin standard shape It would be easy to manufacture and easy to attach parts. But the fluid dynamics would be poor, as the shape is very brick like. The pressure distribution is also poor, causing it to possibly snap.

Ollie Martin

Ollie Martin

Hydrofoil Fin

3.

This shape is based on a race fin. A race fin is designed for speed. The fin shape has a good profile for up wind and downwind sailing.

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Based on a driver fin which is built to be strong, it has good turning capabilities but lacks speed and lift characteristics. It is a different abstract shape compared to the conventional shape. Would appeal to the hydrofoil market as different to the usual set T foil and ladder foil design.

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The evaluation star rating is out of 4 stars, 1.Poor design 2.Average 3.Excellent 4.Perfect These ratings are based on my research and my knowledge

Design

Evaluation: fin shape

Ollie Martin

Comment

Positive

Negatives

The standard style shape of a fin that most people would draw on a surfboard. It is a basic design

Simple design therefore an easy build

Sharp edges, basic shape, standard not new. Not great fluid dynamics

An eccentric fin shape and design. Brings a new concept and style to the fin design. Similar to the driver fin.

New style and querky

Difficult to manufacture and difficult to attach to the foil on, high drag

Star Rating

Basic but brick like.

Difficult and bulky.

Based on a race fin long and thin with a slight slant of 20 °. This is a similar shape to a dagger board so will help out with up windsailing .

Ollie Martin

Hydrofoil Fin

Easy to manufacture and well known shape.

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May reduce ability to turn and jump. Simple and efficient

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Shapes of aeroplane wings

1.

2.

3.

6.

4.

Wingtip shapes, these are common on many aircraft wings. They have a main purpose of pushing the air flow off the wing, to stop turbulence of air flow but they also used to put the electronics of the plane e.g lights, radar etc. They are also an “expression of aircraft design style”.

South African Airways Boeing 747-400 5.

Hydrofoil Fin

Radio Remote Controlled Sail Plane Glider

7.

Aircraft wings have developed over the years with science. This has happened with the greater understanding about the flow of air particles. The air particles act similarly to water molecules. The difference between their behaviour is their density. So these shapes can be adapted into the design, however some of these shape will not work due to the relative travelling speedsa whilst sailing compared to a fighter jet plane.

Ollie Martin

Ollie Martin

Radio controlled Lancair ES

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Design: shape of fin

Ollie Martin This is a 3D view of the design This will be attached by the sandwich method to my board

On the left is foil design based on a bird’s wing. This design came from when I was looking at aeroplanes wings , in my earlier research. Also from nature with buzzards and other high flying predators who have high lift but low speed. This profile pushes the water off the sides of the foils. However this has two major problems, firstly it gives weakness to the foil as there are smaller areas on the edge with high pressure and secondly it is costly to manufacture.

The height of the foil will be 500mm

The fin shape will be based upon an airfoil. This will give the foil and fin the best fluid dynamics in the water which will enable the drag ratio to be lower. This will enable the foil to lift at lower speeds. Both thicknesses of the camber have to be same dimension on the vertical fin otherwise the forces will be unbalanced.

The angle of attack would be 4° a efficient angle of attack.

Buzzard

The length will be 80mm. The width of the foil will be 400mm

Ollie Martin

Hydrofoil Fin

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Design: shape of fin Mark 1. side on view of the design

Mark 2. side on view of the design

Final side on view of the design 170mm bolts

Board attached

Front

The Power box

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Back

Front

Back Front

U N D E R

Back

U N D E R

10°

W A T E R

U N D E R

W A T E R

W A T E R

3° 4°

5°

The drawing above show how the design evolved. The following changes were made: •The angle of attack was increased to 4° to help with lift. •The underwater angle was reversed (following discussion with Mike Cooke) to prevent air molecules being pulled down to the foil and causing turbulence. • The board attachment was further developed to include L section aluminium brackets.

Ollie Martin

Hydrofoil Fin

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4° 5°

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Vertical Fin Profiles

Side profiles of the fin and foil

Ollie Martin

Various profiles were considered based on NACA air foil research. NACA is an organisation that works with NASA, producing research on foils. NASA has spent billions of dollars on research during the cold war and continuing today.

The profile selected for the vertical fin was NACA 0010. This means that there is a 10% thickness to chord length ratio: it is 10% as thick as it is long. The selection was made following research with Mike Cooke. The NACA 0010 is the same aerofoil shape that is used on the Boeing B-17. This creates a high lift with low drag .This is one of the most efficient aerofoil designs made.

Horizontal Foil Profile

The profile selected for the foil was also a NACA profile - a 5313 design. This is a high lift low drag profile meaning that lift can be caused at low speeds.

These profiles will be manufactured by using a CAM machine, so the angles and profiles can be exact to give the perfect shape.

Ollie Martin

Hydrofoil Fin

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The two squares will be attached with nuts and bolts at the four points.

Design: Mark 1. attachment

Ollie Martin This method of attachment was based on the concept that the hydrofoil would be located at the back of the board, and so could use the existing power box ( where the fin is attached).

This one will have the foil attached to it.

To help spread the load, two square plates will be sandwiched together. One plate is attached to the top of the fin and the other plate to the board. The two plates will be bolted together. The upper plate will be attached to the board using the power box .

This rectangle is where the power box fin will be attached.

The squares will be made of aluminium. The circle slot is where a bolt goes in that locks the fin to the board.

The above shape has U.S patent 5,178,553 and is the design of Larry Tuttle.

Ollie Martin

This method will help to transfer the forces and pressure caused by the drag of the foil by spreading the forces over a larger surface area. The size of the plate has been based on the width of boards, which vary from 50cm wave boards to 90cm stable beginner boards. So the dimensions of the square will be 25cm giving a surface area of 625cm² Having a square shape will mean that the board’s handling will not be affected as it will be spread around the board so it will not be unbalanced.

Power Box attaches the fin to the board with a bolt. This is standard fitting on most board so it will be compatible with many different style and brands of boards.

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The design was created when I saw two scraps of L plate aluminium. They kept my plate surface idea. From this attachment further developments where made to the project. The first one was that the profile were going to be stuck to an aluminium core T structure . The T structure gave rigididity to the vertical section but a material that I could make a strong t to by riveting, techno welding or bolting.

Design: Final board attachment

The board attachment was modified for the following reasons: •The hydrofoil was needed to be moved further up the board. As otherwise it would nose dive when it lifts and also it would be difficult to control . •The t on the power box would not spread the forces and all the force would be on the power box which would result in board being damaged or the Hydrofoil snapping off. •The t of the power box to plate and plate to foil were weak and difficult to manufacture. The board in which I intend for the use of the hydrofoil is an old race board called a Bic Velocity. In the centre of the board it has a dagger board that can easily be taken out. When taken out there is a large rectangular hole that goes through the board it is was 150mm from the hull of the board to the This is thickness of the board which means that deck of the board the bolts must be no sorter than 150 mm These holes are perfect for the Profile of the existing dagger board Bolts to go up through. plate on a Bic Velocity

Ollie Martin The bolts will be tightened with nuts

The two plates will spread the force over a larger surface area on the board

The bolts will be water resistant and have a high tensile strength as will be under huge forces.

Dagger board

FIN

The two L plates will be ed by to bolts and nuts that will go through the top of the foil too.

Outline board shape of a Bic Velocity

Ollie Martin

Hydrofoil Fin

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Candidate No:6310

Page: 27

Design: construction method of the foil and fin These are the three segments of the design. They are all made of Styrofoam to create the profiles This foam has great properties for my design. Then these three parts would then be glued to an Aluminium core.

1.

Ollie Martin 2.

Key :

High pressure points

After this process the Styrofoam will be reinforced with fibre glass and carbon fibre impregnated with epoxy.

Where Epoxy resin will be added Aluminium core

The surfaces will be sanded until completely smooth and any surface imperfections will be filled with glass cell then painted with a UV protective and water proof paint. Double sided sticky tape will attach Styrofoam to aluminium 3.

Ollie Martin

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Design- Materials and Construction

Ollie Martin

Materials: They must be light to help to create an easier lift with less force pulling down from gravity. The materials must not react with water as they will be in water when in use. The material must be impermeable to liquids otherwise weight will be added when in the water. The outer coating must be UV resistant as it will be used outdoors in the sun’s UV rays that can damage the fibres. To achieve this a composite solution was considered using: Fibreglass, carbon fibre , aluminium and Styrofoam. Construction: A cnc machine can make the profiles of the foil and fin . This can then be coated with fibreglass or carbon fibre fabric depending on budget, and impregnated with epoxy. This reinforcement with resins creates high strength to enable the design to deal with forces and pressure. When these have cured the next process of sanding down the foils can begin to give the greatest smoothness. This will enable them to have good fluid dynamics. This is a key process in the manufacture. Finally when all these processes have occurred I will paint the product in yellow and black. From the first model any other modification will be added and put into the second design. Manufacturing issues: Resins are toxic, corrosive, irritating and explosive. Glass fibres particles are bad for the respiratory system. Scientific principles: the theory of the hydrofoil, and the temperatures at which the resins have to be heated to give the optimum strength from their properties and finally aluminium techno wielding.

Ollie Martin

Hydrofoil Fin

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Specifications

Key of lines Green Red Orange Blue

Ollie Martin

-Chord length of the fin - Height of the fin -Length of the foil - Chord length of the foil

Foil profile NACA 5313

Design issues : Sandwich- 25cm square Number of foils - 1/2

Length of fin (Flying Height )- 500mm Width of fin – 100mm Width of bottom foil - 400mm Colour – yellow and black Angle of attack of major foil- 4 degrees The foils will be removable so they can be changed depending on the weather condition. This will be achieved by a slot and bolt mechanism, which will be easy to use.

Fin profile NACA 0010

Must consider that no angles may be greater than 15 degrees other wise they will stall. The optimum angle of attack is 3-4º.

Ollie Martin

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Final designs 1.

Ollie Martin 2.

On this design I have added a tail. This improves the appearance of the design as it makes it more original . But it also has a practical use by moving the flow away from the t where the fin and foil meet

These are the designs looking at the different shapes of the T-foil. The shape differs from the brick like shape. As I have added curves on the edges. The designs came from when i was looking at wing shapes.

Ollie Martin

Hydrofoil Fin

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Page: 31

Objective 4 • Developing the best ideas •Manufacturing specification

Design - C.A.D This profile was created by using points to create a semi eclipse I used RHINO as my CAD software because the school’s cnc router was not large enough to manufacture the profiles. So I used a commercial cnc router which only operated with RHINO. I ed the free version of RHINO 4.0 Evaluation off the internet but it only had 25 saves, therefore using the tutorials I learnt the basics before I could start using it for my design. Part of my design, however, consisted of a curve on the end of the foil section, I was unable to do this on RHINO due to my knowledge of the software and the saving limitation. I therefore decided to make it by hand using a template and sanding methods. The foil profile ( aerofoil-6563) that I used was too thin on the bottom camber to be produced with a cnc router so I did not add this to my CAD design but planned to make it by hand using sandpaper instead.

Profiles

This is the profile of the fin section

These are the profiles extruded to their dimensions

This is the final design as a CAD

Ollie Martin

Hydrofoil Fin

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Page: 32

Ollie Martin

Final design

Ollie Martin

Dimensions Height – 500mm Width- 400mm Length- 100mm

Materials: Styrofoam Fibre glass Carbon fibre Aluminium

Ollie Martin

Surface finish- the final layer of glass fibre/ carbon will be sanded then filled with glass cell to fill in any gaps in between the layers. The filler will be sanded down to create a smooth surface. The surface will be sanded using wet and dry paper . After this it will be spray painted with a primer to spot any further irregularities. Then these will be filled with glass cell and then sanded. Then the final coats of yellow and black will be added.

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Model design This model was made by using only sandpaper, lincher, craft knife and a hot wire cutter, as my tools. I used card and Styrofoam as my materials. I created the model in the school workshops. Firstly I drew a template out of card , then cut it out using a craft knife. This template was then stuck by pins to the Styrofoam. Then I carved a T shape out of the foam using a hot wire cutter. From the T shape I used sand paper to create the profiles of the foil and the fin.

This is my template , which was made out of a card. This gave a shape to work from.

Ollie Martin

Ollie Martin Making the model was a very useful exercise for testing my design as from this I discovered that the Styrofoam was not rigid enough as it started to flex with forces of gravity. Secondly that the Styrofoam was easily damaged by a force which created dents in the profile. The positives from the test was that the Styrofoam is easy to shape with sandpaper and a hot wire. From this I conclude that I would need to make the structure more rigid if I was to use Styrofoam, because it flexed easily .

Then I used a hot wire cutter to get the shape from the templates but was unable to do the profiles as they are to small and thin.

Hydrofoil Fin

Centre No:63433

Then to create the profiles I used sand paper and the lincher.

Candidate No:6310

This is the model design that was created at 1:2 scale because the card was not large enough and there was limited styrofoam to create a full scale model.

Page: 34

One-off production

Manufacture: Plan

The T foil 1. Make the profiles with a cad cam machine. 2. Cut the aluminium dimensions out then techno wield them. 3. Use double sided tape to the profiles together. 4. Reinforce the model with fibre glass fabric coated in epoxy resin with hardener . 5. Sand the design down . 6. Paint with UV protective paint and colour scheme.

Ollie Martin The sandwich attachment method. 1. Drill 5 x 6mm holes in L bracket aluminium and top section of fin using pillar drill. 2. Then drill 4 hole on top face of L bracket 8 mm using a pillar drill. 3. One squares ( 250mm x 250mm) cut out of aluminium sheet using a guillotine. 4. Cut out 250mm x 250mm neoprene pad and a 140mm x 210mm with 4 x8mm holes drilled out. 5. Then tighten nuts and bolts

Batch Production The T foil 1.The design will be saved so time and labour saved. 2.The profiles would be made by a company, in mass production, from a mould. 3.The moulds would be filled with glass fibre and epoxy resin with hardener. Then removed from moulds. 4.Sanded down, using a sand blaster will be quicker and also wet and dry. 5.Then sprayed in primer and dents filled with filler this would then be sanded down with wet and dry paper. 6.Painted with UV protective paint and with a large colour scheme with spray and tape technique.

Ollie Martin

Hydrofoil Fin

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The sandwich attachment method. 1.3 350mm bolts will be put into the mould with 150 mm showing on the end. 2.Two 250mm x 250mm squares will be cut out on a production line using a press with 3 holes drilled in. 3.A fabric company will manufacture 2 neoprene 250mm x 250 mm pads with 3 x10mm holes. 4.Then at the assembly line this will be all put together.

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Manufacture: Method

1. 2. 3. 4. 5. 6. 7.

8. 8. 9.

Ollie Martin

Hydrofoil Fin

Ollie Martin

Plan Order Materials. Use cad-cam software to deign the model- RHINO Get the profile machined out using cad cam machine. Cut the machined profiles from the Styrofoam blocks. Cut and shape the lower camber of the project using sand paper and hot wire. Then cut aluminium into the correct shapes using guillotine. Techno wield these pieces together. Stick the Styrofoam profiles on to the aluminium using double sided sticky tape. Drill holes into L brackets and top section of the vertical fin. Fibre glassing. 1. Cut patches of fibreglass for certain areas. 2. Mix up a batch of resin in a mixing pot. 3. Fibreglass cloth saturated with resin. 4. Then leave it to cure in a warm place over night. 5. Repeat this process three times. 6. Then coat surface with filler. 10. Then sand down the whole surface and until there are no defects. 1. Then coat the surface with a primer then a final coat of yellow and black. 2. Attach the foil with the sandwich method. 3. Test it out!

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Mould

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Manufacture: Quality Control

Ollie Martin

I will monitor the whole manufacture of the design. So I will be able to interfere if I see any problems. I will practice the methods of production before making the design, So the methods will become more familiar. When the foam is being shaped by the cnc router machine I will be there checking to see if there are any errors or mistakes. If so I will stop the machine and try to correct them. As the design will be made out of Styrofoam it is easy to sand out errors. When I will coat the model with fibre glass, this can also be sanded down to the preferred shape or recoated if I have sanded too deeply. My product is one that needs the quality to be high otherwise this will cause imbalance in the water and will effect the performance.

Ollie Martin

Hydrofoil Fin

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Design: health and safety issues

Workshop Coat

Safety Goggles

Ollie Martin

When dealing and sanding the pvc foam a dusk mask will needed to be worn as fine dust particles are ejected around and can enter lungs and build up, potentially causing respiratory diseases. People maybe allergic to some degree and get skin reactions from ithe glass fibres. So the majority of my skin needs to be covered up. Carbon fibre and glass fibre is made up of a mat of fibres which are tiny and light weight. So these fine fibre needles are capable of jabbing into your skin or worse - capable of becoming airborne and jabbing into your lungs and eyes, leading to effects such as coughed up blood and splinters. To tackle this issue I will need to wear a breathing mask, gloves and goggles for added safety protection from these fine fibres. Epoxy resin would have to be mixed in a ventilated area. When accelerators or catalysts or hardeners are added caution would need to be taken in to , so that it does not over heat and ignite. . So a fire extinguisher needs to be close by. UV light can break down carbon fibre over time. Therefore I will protect these with a UV protection top coat. This also will add to the appearance as it will give a nice shiny finish. This coat can be found in the paints that I will use. The paints I am using need to be marine tested as I sail on a reservoir and need to be careful not to damage the marine habitat or contaminate human water supplies.

Dusk Mask

Latex Gloves

Ollie Martin

Fire Extinguisher

Hydrofoil Fin

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Objective 5 •Schedule for manufacture • Manufacturing

Manufacturing; Cutting list

Ollie Martin

Part

Quantity

Overall Size (mm)

Material / Description

A

1

3 x 100 x 400

Aluminium / horizontal plate

B

1

3 x 100 x 500

Aluminium / vertical plate

C

2

3 x 100 x 140

Aluminium / L plate

D

1

8 x 100 x 400

Styrofoam

E

2

5 x 100 x 500

Styrofoam

F

2

10 x 100 x 400

Styrofoam

G

1

1.00 kg

SR 5550 - Epoxy resin

H

2

0.29 kg

SD 5505 - Hardener

I

1

0.15 kg

West system 407 Low Density Filler/ Colour brown

J

1

0.07 kg

Glass filler/ Colour white/ Glass cell

K

2

3 x 140 x 210

Neoprene/ Yellow + Black

l

4

8mm

Nylocks nuts and washers

m

4

8 x 170

Bolt / verticals

n

4

6 x 25

Bolt/ horizontal

o

2

6mm

Nylocks nuts and washers

Ollie Martin

Hydrofoil Fin

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Candidate No:6310

Page: 39

Planned economic use of materials

Ollie Martin

Calculations – I used RHINO to calculate area . These are only the dimensions of the Styrofoam not including glass and carbon fibre or the Aluminium.

Surface Area – •Vertical aerofoil 0010 NACA Profile : 2(785.39817mm²) + 500(203.1987633mm)=103170.178 mm² •Horizontal aerofoil 5313 NACA Profile (upper camber only): 2(753.3604)+ 400 (204.3132273 mm) =83232.0117 mm² Total Surface Area = 103170.178 + 83232.0117 = 186402.1897 mm²

Volume – •Vertical aerofoil 0010 NACA Profile : Area = 785.39817mm² x Height=500mm = 392699.085mm³

From the following calculation I was able to work out how much material was needed. This helped prevent over or under ordering quantities. This meant that I used economic quantities of materials. However I had problems when purchasing the set quantities because Matrix moulding sold them by their own set quantities so I had a large amount of glass fibre fabric left over. This however is not a problem as it can be used for further developments of my hydrofoil.

•Horizontal aerofoil 5313 NACA Profile (upper camber only): Area= 753.3604 mm² x Length= 400mm = 301344.16mm³ Total Volume= 301344.16 + 392699.085 = 694043.245 mm³

The Styrofoam used was recycled from a loft insulation. The carbon fibre and the Aluminium L plates were also recycled from off cuts. This saved money and also saved the environment as otherwise it would have been put in the skip.

Ollie Martin

Hydrofoil Fin

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Page: 40

Manufacturing- Tools Tool

Number

Craft Knife

1

Stanley Knife

2

Scissors

3

Paint Brush

4

Plastic Cups

5

Latex Gloves

6

File

7

Sandpaper

8

Sander

9

Hot wire cutter

10

Drill

11

CNC Router

12

Laptop

13

Techno Welder

14

Ollie Martin

Ollie Martin

Hydrofoil Fin

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Candidate No:6310

Page: 41

Manufacture- Method

Methods

Processes

Tools

Ollie Martin

Time

Safety

Quality

Materials

CAD

Deg

Laptop and RHINO software

3 hrs

Power

Visual checks

CAM

Shaping the profiles.

CNC Router

6hr

Getting caught in the machine and dust.

Visual checks

Styrofoam

Techno Welding

ing aluminium together.

2hr

Fire and heat.

Visual checks

Aluminium

Gluing

Attaching the profiles with the core.

Scissors.

0.5 hr

Sharp scissors.

Visual checks

Double sided sticky tape.

Fibre glass coating

Reinforcement

Paint brush, rubber gloves

9hrs

Fumes and spilling resin and hardener ,corrosive and toxic, heat from curing.

Visual checks

Fibre glass fabric, Carbon fibre, epoxy resin and hardener

Ollie Martin

Hydrofoil Fin

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Manufacture- Method

Methods

Processes

Tools

Time

Ollie Martin

Safety

Quality

Materials

Sanding

Smoothing

Sand paper, wet and dry paper and the lincher.

6hrs

Dust particles getting into my respiratory system.

Visual checks

Water

Fillering

Fill in imperfections

Plastic scraper

2hrs

Resin on skin and glass particles in respiratory system

Visual checks

Glass cell , epoxy resin

Sanding

Smoothing

Wet and dry paper

1hr

Dust particles in Respiratory system

Visual checks

Water

Painting

Appearance

Spray can of primer and acrylic paint.

2hr

Fumes, pollution.

Visual checks

Ollie Martin

Hydrofoil Fin

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Manufacture: Others

Ollie Martin

Alternative methods - The reason that many of these methods can not be use is because of cost and that I do not have access to some of the tools. Tools

Reasons for not using it Cost and do not have access

Laser cutter

This would be used to make the model and prototype with a high quality detail and accuracy

Grit blasting

This would save time and make the sanding process quicker

Safety and accuracy

Spray painting

This would improve the finish and speed up the process of painting

Do not have access

Materials Reinforcement Profile

Ollie Martin

Carbon Fibre - Multi directional Corecell

Hydrofoil Fin

This is lighter and stronger than glass fibre. Multi directional would give added strength in most directions. This is pvc foam that is specialised for the Marine industry. It has perfect properties.

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Cost

Cost

Page: 44

PROFILES

Manufacturing- Work Diary

Ollie Martin

Because of the dimensions of the project I had to get the profiles commercially machined, at Howell Farm, Mells, Frome, Somerset BA11 3RH by Code D Machining. The CNC router created the profiles that i had designed on a CAD (RHINO). Styrofoam

The machine part used to carve the shape out.

These are the final profiles after being carved out. They were cut out of the blocks using a craft knife and hot wire cutter.

Ollie Martin

Hydrofoil Fin

Centre No:63433

To create the profile I used sand paper stapled onto a MDF board to create the profile because it was so thin.

Candidate No:6310

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MAKING CORE

Manufacturing- Work Diary

Ollie Martin

Safety

I wore a fire proof jacket and gloves

Cutting

Cutting with the guillotine and tiding up with a file.

I used an wire brush to clean up the surface which i was wielding from any impurities. I used an aluminium rod that was heated up and then melted a long the four areas that were being ed. Then I placed them into the position I wanted with the fire proof blocks reheated up the ridge and then with a spatula I stirred the molten mixture around to create a strong t then left it to cool.

Techno Wielding

Sticking

Ollie Martin

SORRY NO IMAGE AVIALABLE

Hydrofoil Fin

When the weld had cooled ,I used double sided sticky tape to attach the profile to the aluminium T structure that I had created.

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Manufacturing- Work Diary

The hardener was poured in first then the epoxy at a 1: 3 ratio then mixed around in the plastic pot for 30 seconds. Then the fabric was painted with epoxy resin.

On the wing tip and the T t I used epoxy resin and filler to create fillets.

The first layer of glass fibre I did at school but because of the time deadline I was forced to take the rest of the project home over my Easter holidays. This had several benefits as I was able to spend 2hrs a day sanding and glass fibring but it meant I was unable to do as much revision for my other subjects.

Glass Fibre

The glass fibre fabric was cut out using a Stanley knife and a ruler.

Ollie Martin

Ollie Martin

I then painted the surface in which I was going to glass with the epoxy. Then I would wet the glass fibre fabric out with paint brush and place into position.

Hydrofoil Fin

After I had applied the glass fibre, I dabbed it with a paint brush to get rid of any air bubbles, this is what I had learnt from my first layer I did in the workshops at school . These air bubbles made weak points and irregularities in the profile so I had to cut them out using a Stanley knife and filled then with resin.. After this I left the foil to cure in a warm place.

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Sanding was needed after each layer of glassing as there were areas where resin had built up due to gravity , but it was also needed to keep the profile, for this I used three methods of sanding.

1.

2.

A file was used to quickly file out lumps and areas where there had been excess glass and resin (usually on the edges).

In action sanding!

Ollie Martin

Ollie Martin

Manufacturing- Work Diary 3.

A sander was used to quickly create the profiles. It also helped to spot where there were minor lumps which would make the foil uneven.

The end of the fin profile on the vertical section was not parallel with the aluminium end. So I used a hack saw to remove the excess of glass fibre and Styrofoam.

Hydrofoil Fin

Centre No:63433

In the school workshop there is a dust extraction pipe on all the work benches.

I used sand paper stapled on to a wooden board to create an even sand across the surfaces. I used 40, 60 and 120 grit sandpaper for this process

Candidate No:6310

Safety – I wore a dust mask, goggles and gloves along with thick clothes in a well ventilated room.

Page: 48

Earlier on in my coursework I identified these areas as major stress areas so I coated them in carbon fibre off cuts that I was given for free by Mike Cooke.

Manufacturing: work diary

I used the same process as with the glass fibre but instead I soaked the carbon in a greater quantity of epoxy resin. This meant that there would be a good strong t and less chance of getting air bubbles but it also meant there was a lot of sanding to smooth it out.

Ollie Martin

Hydrofoil Fin

Ollie Martin

I was thorough and made sure that there was no air bubbles,it was left to cure in the kitchen.

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Page: 49

A pillar drill was used to drill the 7 holes on the aluminium L plates, that I was given by a builder from his off cuts. I used a ruler, a set square and a pencil to line up the marks for the holes. Then with a hammer and a punch I marked the points, this helped the drill to locate the exact points. Then with a 3 mm drill bit I did the pilot holes. From these pilot holes I drilled four 6mm holes, four 8mm holes and one 4mm whole. When drilling I wore goggles and had the safety switch near to the drill.

Hammer

Drill bit rotating quickly, a danger of getting materials caught in it e.g tie.

A clamp was used to keep the L plate in place and to stop it from moving when drilling. It was also used to help with the lining up of the holes.

Ollie Martin

Hydrofoil Fin

Manufacturing: work diary

Ollie Martin

The rate at which the drill was going into the aluminium was controlled by using the lever. This was done at a controlled and slow pace.

A piece of wood was place under the L plate so that I could tell when I had drilled through the plate and also so that the pillar drill surface was not damaged.

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6mm holes

8mm holes

4mm holes

Aluminium L brackets

From this I was able to the hydrofoil and the L plates of Aluminium together.

Candidate No:6310

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Final Surface finish

400 Wet and dry paper was used to smooth the product down for the first coat of primer.

I sprayed it with a beige high build primer filler . I sprayed it away from myself and started on the outside then came down.

Ollie Martin

Manufacturing: Work Diary

I then taped around the region at which I was going to reinforce latter on with carbon fibre. It was covered with newspaper.

It was left to dry over night in the kitchen.

Hydrofoil Fin

Ollie Martin

I was now able to clearly see the surface imperfection.

The imperfections were then filled with glass cell filler and then left to dry over night

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Then with 120 grit sand paper I sanded the filled region and then used 400 wet and dry paper to give a smooth finish.

Page: 51

Manufacturing- Work Diary

Ollie Martin

Spray can of a beige primer and two acrylic paint black and yellow paints.

News paper and masking tape was used to spray the colour scheme. It was sprayed in a well ventilated room with all the doors and windows open.

I sprayed away from my self at a distance of 20 cm from the project. A thin layer of paint was sprayed and every 10 mins another thicker layer was added.

A problem that i found was that the bolt heads were to wide and would no longer fit through the gap in which I had fillered. So I had to drill out clear to make the bolts fit through.

Ollie Martin

Hydrofoil Fin

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Page: 52

Manufacturing- Work Diary

Ollie Martin

Problems when manufacturing: When Techno wielding straight I found it hard to get the wields to be perpendicular. I redid the wields and used fire proof blocks to align it squarely. Cutting glass fibres fabric cleanly as the ends split really easily, I used glass tape on the ends which did not split and cut it on a board. Glass particles when working in a cellar, I ended with a dry throat and picks on my arm because of this I started sanding out side which solved the problem.

My time management was poor, I had a large amount to do on my project until the deadline, however I managed to solve this by working hard in prep, lessons and my free time.

My project was finished on time but only because I worked on it over the Easter holidays. If I had not done so, it would not have been finished until 2 weeks over the deadline which would clash with my GCSE’s. My coursework was also completed on time however my time management made the last couple of weeks up to the deadline busy and hard work. So if I was to do it again I would have aimed to be in the workshop in October instead of March. This would have given me more time to make a modified product and work on my coursework.

If I was to remake the project it would have been made from a mould as this would save time and improve the accuracy. I would use carbon fibre instead of glass fibre as the particle are larger and do not cause such irritation when dealing with them. I would do the sanding in the school workshop because there is a dust extraction machine.

Ollie Martin

Hydrofoil Fin

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Objective 6 • Evaluation and testing

Date: Sunday 26th April 2009 Location: Cheddar Reservoir (260 acres of water)

Evaluation- Testing

Ollie Martin

Inside the club house on the anometer it was recording an average of 22 knots which is force 6. As it is an inland water the gusts are strong and had been recorded that day to be at 33 knot which is gale force. In these conditions a small sail and board should have been used, however my project was built for a large thin race board and the only small sail I had was for a wave board.

Launch Site

Bristol Corinthian Yacht Club

The wind direction made launching difficult with strong gusts and being blown on shore, but it meant that if I got into difficulty, I would just be blown back to shore. The day was a open day for the club so there were many boats on the water which meant there were lots of obstacles and all the rescue boats were busy so no on water photography could be taken. So the camera man was on the water’s edge videoing which meant that it was hard to see evidence of it in action.

Ollie Martin

Hydrofoil Fin

Centre No:63433

In hindsight these were not wise conditions to test it for the first time as they were tricky to windsurf with the sail being overpowered in gusts and the board being moved by the waves along with a hydrofoil which was tricky to balance.

Candidate No:6310

Page: 53

Manufacturing- Testing

Ollie Martin

I arrived at the reservoir at 2 o’clock . It took me an hour to assemble and attach the product to my windsurf board. Other windsurfers were impressed by the hydrofoil, with many people excited by the concept and commented on the ability to see how it had been manufactured as it had not been fully painted at this stage. Many people were interested to see if it would work and were very inquisitive.

Safety – Lifejacket and Winter wetsuit. Neoprene was used on the surface that was in with the board, to stop any damage to the board.

Waist harness – used as conditions were strong so that I could control the rig.

Boogie boardthis was added to help lift the front of the board out of the water.

Duck Tape – fluid dynamics over the board

Ollie Martin

Hydrofoil Fin

Centre No:63433

Candidate No:6310

Page: 54

Testing Testing log: “I beach started the windsurfer at 1530 in 1 metre deep water. I sheeted in the sail and went off up wind to avoid the jetty. Then I bore away and felt the rise of the board and the speed increase. However a sudden gust unbalanced me and I wiped out. After I surfaced, I flipped the board over to see what condition the foil was in and found it was bent ( see picture below). I was forced to swim with the board back to shore. I landed a shore at 1555”

The bend in the junction of the hydrofoil to the L plate brackets !

I was using a 4.6 metres² aerotech sail rigged with minimum power so that gusts would have a smaller effect

Hydrofoil Fin

Following this testing incident, it was clear that I needed to reinforce the top section of the fin with several layers of carbon fibre where the fin was bolted through the L plates. In addition I found the board difficult to control at low speed with out a rear fin. In my next test this will be added.

The problem that I discovered was that the t where the hydrofoil met the sandwich attachment was not strong enough as it was not reinforced but just 3mm of aluminium . This caused it to bend, I was lucky that it had not snapped otherwise I would have lost my project!

Ollie Martin

Ollie Martin

Centre No:63433

Candidate No:6310

Page: 55

Evaluation- Report

Ollie Martin

I managed to complete the coursework on time although it would have been more useful to test the product earlier in the process. I clearly felt the product was able to do the task of creating lift and increasing speed even though the test was cut short by weather and the weakness of the junction where the Aluminium met the L plate. The product did not gain weight in the water, therefore it must be water resistant. As tested the product was not strong enough to cope in high wind conditions. The size is appropriate for a windsurf board as it is not much wider than the board. However when I make my next version in will be wider by 100mm along the foil section and also have sharper edge son the leading edges so that it can cut through the water more efficiently. The interest generated by the hydrofoil on the shore was clear evidence that windsurfers found it an interesting and attractive product. The final coat of paint makes the product even more attractive and appealing. The design is easily repairable as any dent that occurs to the product can be easily be filled using glass cell and epoxy resin. This will help to keep the product in good working condition. The product can easily be cleaned using soap and a damp cloth. The product is not easy to alter and it is not easy to replace parts because of its composite construction. The product has been reinforced with several layer of glass and carbon fibre so the strength is there in the structure to make it last for 3 years, obviously after correcting the weak area indentified in testing. The fillets, the wing tips and the profiles along with the layers of paint have added to aesthetics of the design. The shape was commented on positively by the windsurfers at Axbridge reservoir.

Ollie Martin

Hydrofoil Fin

Centre No:63433

Candidate No:6310

Page: 56

Evaluation - Report

Ollie Martin

The design has been based on the large amount of research under taken by NACA. The actual dimension chosen for the foil and fin, took into the need to have something easy to assemble and carry. I feel that the product meets these criteria. The materials were selected to produce a strong yet light hydrofoil that was impermeable to water. The Styrofoam profile, carbon and glass fibre, and epoxy worked well together. However the aluminium core added considerable weight without adding structural stiffness. In the future I will not use this material as the core, instead I will use plywood as a core which is lighter, easier to shape. The epoxy/ fabric covering will provide all the product needs. The weight of the product is within tolerance of specification but ideally would be lighter as it weighs 2kg. All sharp edges have been smoothed on the product to avoid severe injury. Further testing is required to ensure that the product is safe for windsurfing in more exposed locations. I have managed to keep the costs with in budget by spending a total of £ 78.64. This was helped by donations of Styrofoam and carbon fibre. The manufacturing process was appropriate for a one off production. However the next stage would be to produce a mould to enable more efficient production. The design complies with relevant regulations although a CE certificate maybe required, it would also be necessary to seek legal advice on copy right issues before starting mass manufacture.

Ollie Martin

Hydrofoil Fin

Centre No:63433

Candidate No:6310

Page: 57

Evaluation: Modifications Ollie Martin Carbon fibre Layer and fillering.

Sanding

Drilling

I used the work shop benches to straighten the bend. I did this slowly and carefully. As I was aware that the aluminium was now very weak and could easily snap. I used a set square and a spirit level to check that these were square.

Plate bolted.

The overlap on the L plate attached to the hydrofoil was filled with epoxy filler. This gave strength to this section because it had nothing but air between the two plates when they were ed.

The carbon fibre that I used for this t was sanded down with 80, 100, 120, 160 grit sand paper then finally finished with 400 grit wet and dry paper.

This was then sprayed in primer and then imperfection were filled with glass cell and this was then sanded down to give a smooth finish. The wholes that had been covered be carbon fibre were redrilled out using a cordless drill.

From my testing I had learnt that the bond next to the plate and project was weak with only 3mm aluminium. This was reinforced by making two layers of carbon fibre and epoxy and the nuts and bolts were tighten up to full strength.

Ollie Martin

Hydrofoil Fin

Centre No:63433

Candidate No:6310

Page: 58

Resources http://carafinohydrofoilboard.com/products.html

Ollie Martin

http://web.mit.edu/2.972/www/reports/hydrofoil/hydrofoil.html

http://www.rushrandle.com/hydrofoil.htm http://www.supramar.ch/ http://www.hydrofoilsurfing.com/id12.html http://www.tspeer.com/Hydrofoils/generic.pdf http://web.mit.edu/2.972/www/reports/hydrofoil/hydrofoil.html http://www.exigent.info/miller.pdf

Ollie Martin

Hydrofoil Fin

Centre No:63433

Candidate No:6310

Page: 59