Week 17 Log A & B

Things Accomplished:

• Handed in completed Developmental Work thus far

Week 16 Log B

Things Accomplished:

• Drawings finished
• Need to finish lists

Week 16 Log A

Plan For The Week

• Adding detail to drawings
• Need to finish Plan of Procedures

Week 15 Log B

Things Accomplished

• Worked on Exploded View: Added thickness
• Started Plan of Procedures Lists

Week 15 Log A

Plan for the week

• Begin Developmental Work

Week 14 Log B

Things Accomplished

• Bid Prcoess completed

Week 14 Log A

Things Accomplished

• Finished 3 bids for the skirt material and its adhesive

Week 13 Log B

Things Accomplished

• Work ethic at an all time low today. Played SEGA and cards
• Still in the process of gathering materials and the appropriate quantities
  

Week 13 Log A

Things Accomplished

• Began mathimatical calculations
• Started working on Bid Process for materials

Week 12 Log B

Things Accomplished

• Started working on an orthographic drawing

Week 12 Log A

Things Accomplished

• Finished a 3D drawing on AutoCAD

Week 11 Log B

I'm blogging from home because I'm sick.

• Started working on drawings in AutoCad

Week 11 Log A

Things Accomplished:

• Handed in mentor contacts

Week 10 Log A & B

*Formal Report of Progress Presentations*

Week 9 Log A & B

Things Accomplished:

• Revised presentations

Week 8 Logs A & B

*Informal Report of Progress Presentations*

Week 6-7 Logs A & B

Things Accomplished:

• Finished revisions on solutions
• Built model

Week 5 Log B

Things Accomplished

• Searched for parts
• Continued Revisions

Week 5 Log A

Things Accomplised

• Communicated with mentors about parts
• Started solution revisions

Week 4 Log B

Things Accomplished

• Rationale Submitted

Week 4 Log A

Things Accom[plished

• Rationale Completed

Week 3 Log B

Things Accomplished

• Write selection/rejection/intention report for final solution
• Posted s/r/i on blog

Research

 Structural Information 

Net System
   •  Rope pulley attached to rotating motor engine
   •  Lowering mechanism

Power
  Engines
   - Electric
     o Refer to http://electronics.howstuffworks.com/motor3.htm
   - Gasoline
     o Refer to http://www.howstuffworks.com/engine.htm

                            Pros                                      Cons

    Electric           -small                           -limited power output

                          -quiet                           -dangerous near water

                          -inexpensive

                          -lightweight

    Gasoline         -excellent lb/hp ratio            -costly

                          -safe                                   -possibly heavy

                                                                     -volume

                                                                     -vibrations

                                                                     -noise

Types of Electric Motors (Taken from: en.wikipedia.org/wiki/Electric_motor)

AC Induction

• Advantages: Least expensive, long life, high power
• Disadvantages: Rotation slips from frequency, low starting torque
• Typical Application: Fans
• Typical Drive: Uni/Poly-phase AC

AC Induction (split-phase capacitor)

• Advantages: High power, high starting torque
• Disadvantages: Rotation slips from frequency
• Typical Application: Appliances
• Typical Drive: Uni/Poly-phase AC

AC Synchronous

• Advantages: Rotation in-sync with frequency, long life (alternator)
• Disadvantages: more expensive
• Typical Application: Motors, clocks, audio turntables, tape drivers
• Typical Drive: Uni/Poly-phase AC

Stepper DC

• Advantages: Precision positioning, high holding torque
• Disadvantages: Requires a controller
• Typical Application: Positioning in printers and floppy drives
• Typical Drive: Multiphase DC

Brushless DC Electric Motor

• Advantages: Long lifespan, low maintenance, high efficiency
• Disadvantages: Expensive, requires a controller
• Typical Application: Hard drives, CD/DVD players, electric vehicles
• Typical Drive: Multiphase DC

Brushed DC Electric Motor

• Advantages: Low initial cost, simple speed control, (Dynamo)
• Disadvantages: High maintenance (brushes), Short lifespan
• Typical Application: Treadmill, exercisers, Auto-starters
• Typical Drive: Direct PWM

  Batteries

• Refer to  http://www.howstuffworks.com/battery.htm

Steering
   Fins vs. Shutters

                            Pros                                      Cons

    Fins                -lightweight                         -fragile

                          -simple construction             -lower efficiency

    Shutters          -better control                     -heavy

                          -higher efficiency                 -requires a frame

                                                                    -difficult construction

Brainstorming Drawings

The following pictures are sketches of ideas AC and I had while researching over the summer. Most of the pictures don't have scales because they are just ideas and possibilities that have not been developed further or have been drawn in more detail in a different post.(If you click on the picture it will open up bigger in a new window).

Rough Sketch of Propulsion and Steering Ideas

This drawing represents multiple solutions for the problem of propelling and steering the hovercraft. In some cases, steering and propulsion can be combined

Rough Sketch of a Potential Motor and Battery System

This drawing is an average sized motor that may be used in constructing the hovercraft.

Rough Sketch of a Hull Design

• Composed of three Jupe Skirts (bottom of sketch) and a rounded, convex top (top of sketch).
• A slit in the convex top will be cut out to place a mechanized wheel system that can deploy and retrieve the plankton net by unwinding and rewinding.

Rough Sketch of a Hull Design

• Composed of two Segmented Skirts (bottom of sketch) attached to a low, flat top (top of sketch).
• A slit in the top will be cut out to place a mechanized wheel system that can lower and raise the plankton net into the water.

Rough Sketch of a Hull Design

• Composed of a Bag Skirt (bottom of sketch) and a trapazoidal prism (top of sketch) will sit on top of it.
• A slit in the top will be cut out to place a mechanized wheel system that can deploy and retrieve the plankton net by unwinding and rewinding.

Rough Sketch of a Hull Design

This drawing shows the top front and left side views of the exterior. It has a structure to hold a plankton net and the motor for it. This structure resembles those used on research vessels that pull nets

Alternate Solutions

The following pictures are more elaborate and proportional drawings of some of the rough sketches from the brainstorming section. Most of the pictures don't have scales because the hovercraft must be designed perfectly to compensate for the weight of the electrical assets which have not been decided on yet. (If you click on the picture it will open up bigger in a new window).

Alternate Solution 1

Orthographic View of Design #1

Isometric View of Design #1

Design 1 has a closed, semi-circle hull as labeled “A” in both drawings below attached. Three round Jupe Skirts will be attached in a triangular pattern to its underside; one rounded skirt at each of the points of the triangle (labeled “B”). The rounded hull will be hollow, allowing space for motors and other electrical necessities to sit, as shown in Figure 1. A narrow slit will be cut out of the top of the rounded hull. This space will be used to holster the geared pulley system that will deploy and retrieve the plankton net (labeled “C”). This system will be activated by an electric motor. It will wind and unwind which will ravel and then unravel the plankton net. Inside the hull, one Lift Fan will be situated in the rounded “floor” of the hull so that air can reach the fan. The Lift Fan, when activated by an electric motor, will inflate the skirts that will produce the cushion of air that lets the craft “hover”. One or two fan propellers (not shown in the drawings) will be bolted to the back of the hull, standing vertically, to boost the craft forward. To steer the hovercraft AC has designed a few different systems which are illustrated and better explained in the brainstorming section. One of these steering systems (to be determined) will be applied to the hull.

Pros

·        Easy construction

·        Simple design

·        Electrical equipment easily attached and stored away from the spray of water.

Cons

·        More skirts = more drag = less efficiency = more required horsepower

·        Plankton Net can possibly get caught in equipment

·        Multiple motors needed to power fans and gear system = $$$

  

Alternate Solution 2

Orthographic View of Design #2

Isometric View of Design #2

Design 2 consists of three rectangular, flat platforms all adjacent to each other. The two side platforms will each have a Segmented Skirt (labeled “A”) attached to the underside of the platform. Each platform top will have the motor and fan needed to inflate the skirt attached to it (labeled “B”). The two side platforms will be attached to a center platform, which is raised slightly higher than the two sides. The center platform will house the geared pulley system that will deploy and retrieve the plankton net and the electrical necessities that will go with it (labeled “C”). In the middle of the center platform a narrow slit will be cut out that will holster the geared pulley system. The net will hang under the platform freely and the pulley system will lower and raise it when activated. On the back of each side platform, one fan propeller (not shown in the drawings) will be bolted vertically. These two fans will thrust the craft forward. To steer the hovercraft AC has designed a few different systems which are illustrated and better explained in the brainstorming section. One of these steering systems (to be determined) will be applied to the hull and would need a motor.

Pros

·        High Stability

·        Ease of Steering

·        Net system won’t get tangled

Cons

·        More skirts = more drag = less efficiency = more required horsepower

·        Multiple motors needed to power fans and gear system = $$$

Brittle structure; higher chance of breaking under weight

Alternate Solution 3

Orthographic View of Design #3

Isometric View of Design #3

        Design 3 has a very basic hull shape. It is slanted in the front, flattens off, and then slants back down. The sides are flat as well (labeled “C”) . The two slants in the front and back, attach to a Bag Skirt (labeled “A”) under the hull. The hull will be hollow, allowing space for motors and other electrical necessities to sit. A narrow slit will be cut out of the flat top. This space will be used to holster the geared pulley system that will deploy and retrieve the plankton net (labeled “B”). This system will be activated by an electric motor. It will wind and unwind which will ravel and then unravel the plankton net. Inside the hull, one Lift Fan will be situated in the flat “floor” of the hull so that air can reach the fan. The Lift Fan, when activated by an electric motor, will inflate the skirt that will produce the cushion of air that lets the craft “hover”. One propeller fan (not shown in the drawings) will be attached to the back of the hull to thrust the craft forward. To steer the hovercraft AC has designed a few different systems which are illustrated and better explained in the brainstorming section. One of these steering systems (to be determined) will be applied to the hull.

Pros

·        Simple hull design = easy construction

·        Bag Skirt easily made

·        Electrical equipment easily attached and stored away from the spray of water.

Cons

·        Difficulty installation of propeller fan

·        Plankton Net could possibly get caught in workings

·        Not aerodynamic = possible steering difficulties

Alternate Solution 4

Orthographic View of Design #4

Isometric View of Design #4

This hovercraft is a round-ended rectangle based on an internal frame structure. It is longer than a circle for forward stability. It is lifted by two fans (labeled “A”). These fans are located on both sides and towards the front of the craft. Both fans are connected to one motor by means of belts. It is propelled by a fan in the rear (labeled “B”). Attached to the propulsion fan is a shutter box, which houses the shutters that steer the craft. Part of the frame is a structure that holds the net system, which will deploy and retrieve a plankton net (labeled “C”). This system has its own motor for retrieval. This structure rises above the components of the hovercraft, such as the fans, so the line will not interrupt the functions of those components. The fans, motors, batteries, and all other components will be external for purposes of construction and maintenance.

The internal frame is heavy and will slow the craft down, but will increase stability and momentum when pulling the net. This added weight will also decrease steering effectiveness. Having two lift fans increases output, hover height, and dependability but uses more power and is more difficult to construct. Having a single propulsion fan uses power more efficiently, but using shutters to steer the craft is not. However, shutters are the most efficient of the readily available steering systems. Having the net system above the hovercraft will keep the motor and line out of the way, but the line may get caught if it goes slack. Having the system on the side of the hovercraft will keep the line out of the way but will not balance when towing the net. Making the hovercraft components external will possibly expose them to water, but will be easy to attach and replace if necessary. If the first solution doesn’t work out, I think this solution will be next.

Selection/Rejection/Intention Report

 

(If you click the chart it'll get bigger.)

According to the above list, solutions #2 and #4 are the most viable as final solutions. Both solutions ranked equally on the chart but AC and I are going to further develop solution #2 because of personal preferences. Solution #2 has the best design for the functionality necessary for the project It will have a low profile and will be long in length which creates stability and balance, and dissipates a greater weight. Because creating an electrical grid and making it controlled remotely will be a challenge in itself, an easily constructed and conceivable hovercraft design is ideal. Due to its accessible design and apparent ease of construction, solution #2 is chosen to be our final solution

Final Solution

Orthographic of Final Solution

Isometric of Final Solution

Week 3 Log A

Things Accomplished

• Redrew alternate solutions
• Posted solutions on blog

Background Information

 Taken from: http://www.westlakes.org/projects/environment/media/Plankton_Sampling.jpg

       The national park of Sandy Hook, New Jersey, is home to various environmental features and niches. The majority of the Hook is uninhabited by people because it is inaccessible. Sandy Hook is also home to the NOAA research lab. The NOAA lab cannot retrieve accurate data because they do not have the ability to take water samples in the inaccessible marshes on the Hook (Figure 2).
        To overcome this problem the NOAA lab has asked the Marine Academy of Science and Technology Systems Engineering II students to design and construct a solution: a miniature hovercraft (resembling the ones in Figure 3). The miniature hovercraft, with its ability to float over the water level, will leave the ecosystem of the marshes undisturbed. The hovercraft will also need a system that can deploy and retrieve a plankton net (Figure 1). This system will allow for the researchers to take accurate water samples.
        Two students will work together to design and construct the hovercraft. The processes that will turn an idea into a reality will be divided into two parts. One student will take on the role of a mechanical engineer and the other student will take on the role of a civil engineer. For this project VR will be the “structural engineer” and AC will be the “mechanical engineer”.
        The job of the civil engineer is to design the structure of the hull and net system. The hull will need to be stable, small enough to maneuver through foliage but big enough that it can hold the mechanisms that will make it float. The job of the mechanical engineer is to design the propulsion and steering systems. These are both essential to the hovercraft so that it can be controlled and “hover”, which is the purpose of the project.
        This project will be continued throughout the students’ senior year at the Marine Academy. They will labor diligently in their Systems Engineering II class to finish their work and project on time. They will work in collaboration with their two mentors and instructors to produce a functional model by the end of the school year.

Figure 1: Plankton Net (Taken from: www.rickly.com/as/BenthicAqSa.htm)

Figure 2: Salt Marsh (Taken from: http://www.capturethisphotography.com/labels/Jersey%20Shore.html)

Figure 3: Mini-Hovercrafts

(Taken from: http://www.gadgetgalaxy.com.au/Radio%20Control%20Helicopters.htm)

Design Brief

Team Design Brief:
        The NOAA lab needs to catch plankton in the inaccessible parts of Sandy Hook; however they do not want to disturb the ecosystem. The situation is to design and construct a remote controlled miniature hovercraft that can deploy and retrieve a plankton net. The hovercraft will be suspended above water level by air propulsion so as to not disturb the environment.

Specific Design Brief:
       To design and construct a sturdy structure of the hovercraft that will house the necessary equipment that will make the hovercraft systems work.

Specifications

• Must be remote controlled
• Must be battery powered
• Must be suspended above ground or water level by air 

• Must have a system for deploying and retrieving a plankton net
•  Should be positively buoyant in case of propulsion failure or miscellaneous malfunction
• Needs high stability  
• Must properly protect the mechanical systems from water. 
• Design must be conceivable
  

Limitations

• Materials: Wood, metal, sheet plastic, rubber tubing, gears, fiber glass and its adhesive
• Time: Research, design, development, production, quality control
• Capital: Lab, Materials available, Equipment, Supplies, Parts
• Tools and Equipment: Band saw, belt sander, scroll saw, drill press, drill gun, airbrush pen, compressor, hack saw, utility knife, scissors, nails
• Information: Instructions, research, working drawings, specifications
• People: Instructors, mentors, hobby shop owners/enthusiast

Week 2 Log B

Things Accomplished

• Posted Summer Work on Blog

Brainstorming: Problems To Be Solved

Propulsion
   Motor
     - electric - best option for situation, but a minor safety hazard
     - gas - too heavy and large for a small hovercraft
  Power source
     - battery - reliable, availible for use
     - solar - dependent on sun, not the best option
  Fan
     - blade size / weight - should be proportional to calculations
     - number - dependent on design
     - location - dependent on design

Steering:
  Fins
     - shutter - most commonly used
     - airfoil - used for r/c hovercraft
    Rotating (2 fans) - complicated construction
    Pivoting (1 fan) - complicated construction
    Stationary (2 fans) - multiple controls needed

Hull Design
   Cushion / Skirt
     - material: rubber,
     - shape: circular, enlongated, etc.
     - style: Jupe, Bag, or Segmented
   Base
     - material: plastic, rubber, metal
     - shape: shape of skirt, rectangular, circular
     - motor and fan mounting location: top, middle, side, etc.
   Plankton Net Mount
     - weight: N/A
     - location: top, middle, inside
     - size- N/A
     - motor needed: most likely

Testing Procedures

Propulsion/Steering Testing:
  1. Meet with team.
  2. Turn power on.
  3. Place in water.
  4. Check functionality of fans and rudder using remote controls.
  5. Steer craft to desired position and engage net system, lowering the net.
  6. Tow net desired distance.
  7. Engage net system and reel in net.
  8. Steer craft back to starting point.
  9. Take out of water
  10. Turn power off.

Structure Testing:

  1. Place in water to ensure positive buoyancy in case of motor failure.
  2. Within procedure for propulsion, assess stability when:
      a. Moving
      b. Still
      c. Towing
      d. Retrieving
  3. Remove from water.
Overall Design Testing
  1. Meet with client at designated test site (right)
  2. Place hovercraft over water level of the pool
  3. Turn on hovercraft and let go
  4. Hope that the hovercraft will float
  5. Attach plankton net to deploy-retrieve system.
  6. Launch plankton net
  7. Retrieve plankton net.
Test Site: Horseshoe Cove  (Aerial View. Picture Donated by Mr. Christiano, Sandy Hook Park Ranger)

Past Solutions

Fitzgerald, Christopher, and Robert Wilson. Light Hovercraft Design. 3rd ed. Foley: The Hoverclub of America Inc., 1995. Print.


        This publication has given information and mathematical equations for the better understanding of the workings of hovercraft. It gives a presentation of all useable equipment, materials, and styles available. It shows hand drawings of skirts, motors, layouts, and fan systems. It makes comparisons between skirt types in different situations and terrain which is necessary to know to assign the correct skirt type. Information on appropriate engines and propellers is helpful to designing the propulsion system. Although it concerns mostly hovercraft intended for people, it helps in understanding how hovercrafts work in general.

Bibliography

"Battery." How Stuff Works. Web. 2 Aug. 2009.
    .
"Benthic Aquatic Sampling Equipment." RICKLY HYDROLOGICAL COMPANY. N.p.,
    2009. Web. 2 Aug. 2009. .
Capture This Photography. N.p., n.d. Web. 2 Aug. 2009.
    .
"Electric Motors." Wikipedia. N.p., July 2008. Web. 2 Aug. 2009.
    .
"Engines." How Stuff Works. N.p., n.d. Web. 2 Aug. 2009.
    .
Fitzgerald, Christopher, and Robert Wilson. Light Hovercraft Design. 3rd ed.. Foley: The
    Hoverclub of America Inc., 1995. Print.
McLeavy, Roy. Hovercraft and Hydrofoils. New York: Acro Publishing Company, 1976.
"NYC Regional Geology." U.S. Geological Survey . N.p., n.d. Web. 2 Aug. 2009.
    .
"Radio Controlled Gadgets." Gadget Galaxy. N.p., n.d. Web. 2 Aug. 2009.
    .

Week 2 Log A

Things Accomplished

• Started blog
• Revised Summer Work

Test Post

Testing