WaterCopter STEMM Report

The WaterCopter_____________________________________________________________________

Problem

Many marine biologists and chemists require the collection of water samples to conduct research on the conditions of various bodies of water. The primary method of sample collection is by hand from a boat or shore. Samples are also taken using tools such as Kemmerer bottles or underwater drones, but must be deployed manually and utilize a tether.

Although these methods have been the norm in the past, there is now concern that the vehicles used to take these samples disrupt the environment unnecessarily. In addition, areas that should be tested for water quality are left untouched because they are inaccessible by boat or dangerous to access from land. Therefore, we must create a vehicle able to access bodies of water remotely, take a pure water sample with negligible environmental impact, and return the sample to the user for testing. The projected users of the product are research scientists, marine biologists or chemists, ecologists, park employees, or any person interested in marine research.

Marine Scientists frequently sample water to analyze the health of various ecosystems. The data derived from these samples provides insight into how humans affect the environment, and how the wildlife of the respective ecosystems react to the changes. While these scientists mean well, the most common means of sampling water disrupt the very ecosystems they aim to save.

Solution

Our goal as a team is to develop and manufacture a remotely operated vehicle to survey and take samples, causing minimal negative impact on marine environments inaccessible or dangerous to the researchers and scientists that control and utilize this vehicle periodically in locations of interest, in order to research water quality.

My individual purpose is to Develop and manufacture a structure and aerial lift system, used periodically throughout the year to maneuver through dense environments and carry water samples from bodies of water for scientists to analyze and record, to allow for less obtrusive research in locations less accessible to humans.

The WaterCopter is a remotely operated aerial vehicle capable of sampling water. The Final solution for the chassis of the quadcopter is a Kydex 100 shell. The Kydex thermoforms into a top and bottom half of the desired shape and secures with zip ties on either side of a silicone gasket (as shown in figure 1). This shell contains the electronic and mechanical components of the quadcopter, which includes both the control system and sampling system.

Figure 1: The WaterCopter chassis assembly, including the top, bottom, and seal.

Engineering_________________________________________________________________________

Classification

The WaterCopter Chassis is an innovation of thermoplastics and current quadcopter technologies. Kydex 100 is most commonly used in aircraft interiors, but the WaterCopter utilizes the material for the exoskeleton of the vehicle. The quadcopter itself is both an information and technological open system that can respond to stimuli automatically or through manual inputs; the electrical components process information and controls the mechanical components that transport the water sample.

Fields

The WaterCopter was designed using principles from aerospace engineering, materials engineering, and structural engineering. Aerospace engineering centers around creating flight. The WaterCopter uses four motors and propellers to establish lift and achieve flight. The propellers create lift through the Bernoulli Principle, which states that split air particles travel faster over curved surfaces than flat surfaces. A difference airspeed on either side of an object (in this case the propeller) creates a pressure differential that pushes the object into the low pressure area.

The exoskeleton of the vehicle is composed of a thermoplastic called Kydex 100. Constructing the shell utilizes many materials engineering concepts. The Kydex 100 must be strong and highly manufacturable. As a result, the plastic was designed to become very moldable at 350 degrees Fahrenheit. This molding process requires a bladder to pull the Kydex around the vacuum form. Materials engineering was again used in the selection of silicone to act as the vacuum bladder. Silicone has can stretch 600% before tearing and withstand 428 degrees fahrenheit.

The purpose of the chassis is protecting the electrical and mechanical components that control and move the quadcopter. In order to create a strong shell, I used structural engineering principles while designing the exoskeleton. The WaterCopter was designed to be durable in case of collision while operating in dense environments. Kydex 100 derives its strength from the contours of its molded shape. The more creases and corners in the kydex, the stronger the shell is. Therefore, when designing the shell I used corners and angles instead of slopes and curves.

Manufacturing_______________________________________________________________________

Types

The Craft System of manufacturing is used to produce the vacuum table, seal, and zip tie anchors. The vacuum table is constructed with drills and saws. The top is hollowed out with a saw and the bottom is drilled to produce the suction holes. The waterproofing seal is cut out of the silicone vacuum bladder. The zip tie anchor holes are drilled out of the exoskeleton and cut out of the seal.

The American System of manufacturing is applied to the shell. The kydex halves are produced from identical molds and thus can be replaced if any damage is sustained. In the same respect, the  mold and vacuum forming process can be used to mass produce the WaterCopter if demand is high for the water-sampling quadcopter.

Lean manufacturing is used in the production of the seal. The seal is cut out of the same silicone used for the vacuum bladder. This minimizes waste as the bladder would not be used after constructing the WaterCopter. This production decision also saves money, as a separate seal does not have to be purchased.

The vacuum forming process is an example of Rapid Manufacturing. Vacuum forming uses molds to produce identical plastic shells. Any number of shells can be produced at the same time depending on how many vacuum presses and forms one has. In addition, the vacuum forming process is very fast compared to other means of manufacturing plastics.

Categories

The WaterCopter falls under two manufacturing categories: industrial and plastics. The exoskeleton was designed to be produced through vacuum forming. The process is easily replicable and a very precise way of producing a finished product. The vacuum forming process is also a type of manufacturing exclusive to plastics.

Science_____________________________________________________________________________

Applied Concepts

The primary science concept of the WaterCopter is Aerodynamics. The vehicle is designed to fly and carry a load; the more aerodynamic the chassis, the better the quadcopter operates. The chassis is designed to facilitate the movement of air over the surface of the exoskeleton, as the propellers produce propwash that collides with the chassis and reduces the lifting capacity of the vehicle. Flight is achieved through the Bernoulli Principle, which (as shown in figure 2) states that split air particles travel faster over curved surfaces than flat surfaces. A difference airspeed on either side of an object (in this case the propeller) creates a pressure differential that pushes the object into the low pressure area. The most accessible example of the Bernoulli Principle is an airplane wing, which has a convex top and a curved bottom to produce lift at high linear speeds. A propeller exhibits the same characteristics, but utilizes a tangential (or rotational) velocity instead of a linear velocity.

Figure 2: Bernoulli’s Principle shown  through a cut out view of an airfoil or wing/propeller.  (“Bernoulli’s Principle”)

In addition, the  WaterCopter lands and takes samples directly from the surface of the water. In order for this to be possible, the quadcopter must be positively buoyant. The density equation [density = mass / volume] must be used to determine if the quadcopter is positively buoyant, or the density is less than 1 kg/m^2.

Technology_________________________________________________________________________

Design Process

During the design of the solution, AutoDesk Inventor was used to produce 3D and 2D drawing of the WaterCopter as the final solution changed and developed (see figure 3). Autodesk Inventor facilitated the design of the exoskeleton, as well as the resultant molds used for the vacuum forming.

Figure 3: The WaterCopter chassis top half designed on AutoDesk Inventor.

Solution Production

The production of the WaterCopter utilizes many technologies. This includes a 3D printer to produce the mold for the vacuum forming. In addition, a vacuum table and silicone bladder is used to manufacture the exoskeleton of the vehicle (see figure 4).  The shell itself is constructed of Kydex 100, a thermoplastic specifically designed to be easily moldable at 350 degrees fahrenheit.  

Figure 4: The vacuum forming process illustrating the purpose of the silicone bladder.

(“Vacuum Frame Press Products”)

Mathematics________________________________________________________________________

Math Concepts

The WaterCopter must carry over 1 Kg of material. In order to achieve this, the vehicle has to provide enough lift to move this amount of mass. The lower the KV of a motor, the more torque it produces and a slower speed. A larger propeller produces greater lift at a lower speed (See Figure 5). Thus, in order to maximize the thrust produced by the propellers, the WaterCopter utilizes 800 KV motors and 12” propellers.

Figure 5: Brushless motor test record illustrates the relationship between motor KV, propeller size, and thrust. (“Emax...Motor”)

STEMM_____________________________________________________________________________

Solution Analysis

The WaterCopter is an innovation uses principles from aerospace, materials, and structural engineering. The production process involves the Craft, American, Lean, and Rapid systems of manufacturing, with expectations of mass production after testing the final product. The WaterCopter was designed on AutoDesk Inventor to be aerodynamic and capable of lifting a Kg of mass.

The WaterCopter

The WaterCopter is a remotely controlled aerial vehicle designed to sample 500 mL of water from marine environments. These samples are used to diagnose problems in that ecosystem and help the inhabitants live healthier, without disrupting the environment with humans, boats, or underwater drones. The WaterCopter aims to make water sampling faster, easier, and less harmful to the environment.

Works Cited

"Bernoulli's Principle." The Physics of Sailing. Web. 19 Feb. 2015.

"Emax XA2212 820KV 980KV 1400KV Brushless Motor For RC Models."BangGood.com. Web. 19 Feb. 2015.

"Vacuum Frame Press Products." Vacuum Laminating Technology Inc. - Vacuum Frame Press Products. Web. 19 Feb. 2015.