As a method of air-breathing propulsion, turbojet engines have the advantage of being highly efficient, but this comes at the cost of mechanical complexity and consequently high manufacturing price. With this in mind, the primary goal of this project was to explore the ways in which turbojet complexity could be reduced while still maintaining high levels of efficiency. This was done by researching the principles on which turbojets operated, identifying the causes of fuel efficiency as well as the conditions necessary for combustion. A design was hypothesized that utilized solid fuel with a weak chemical oxidizer, in theory allowing for compressor efficiency to be low while still achieving combustion. Because it was unknown whether a partial chemically-oxidized fuel could still be further oxidized by compressed air, several preliminary tests were conducted. The results showed that this was possible, supporting the feasibility of this engine and allowing the experiment to continue. The next step was to test whether a partially-oxidized fuel could solely sustain compressor start-up, as this would precede atmospheric oxidation and the combustion would be inherently weak. A solid-fuel turbine was designed and built, being designated as Prototype 1. In addition to testing deoxygenated compressor startup, Prototype 1 demonstrated whether the simple materials used in construction could withstand the extreme conditions of a turbojet engine. The results of the test revealed that the turbine accelerated to 6,300 RPM in 2.33 seconds, proving the feasibility of deoxygenated startup.
Accessibility in the Shop
For my capstone project, I created resources to help new engineers in SLA get their footing. I started by labeling each machine with easy to read, laminated cards. Then, I focused on the laser cutter, which was about to endure the Rube Goldberg project, which uses it heavily. The guide that already existed was bare-bones, so I added a lot more detail. After the laser cutter guide was finished, I was unsure of what to do next. That’s when mr. Kamal introduced me to the wonderful world of 3D printing. Over a few months, I wrote tutorials for all four printer models in the shop. Each tutorial is connected to a 3D printing master document. It has a set of stats comparing each printer alongside recommended uses. For example, the Form 2 is arduous to use and clean, but the result is beautifully smooth. Alongside the master document, I printed the same model on each printer. I chose 3DBenchy as the example model, which is a small cartoon boat commonly used to calibrate printers. I then mounted them side by side. Using the mount, a beginner can scan the QR code and reference the example prints to decide which printer to use. Overall, this project was engaging the whole way through. I never thought I’d be interested in 3D printing; it always seemed too limited to be useful. I’m more excited than ever to learn more, and maybe even get a printer of my own in the future.
Above are the example prints and the 3D printing master document.
For my capstone, I decided to explore Fusion 360, which is a 3D modeling software. Over the course of the year, I made fifteen projects in Fusion 360, exploring the different tools and workspaces available in the software. I used a variation between tutorials I found online and designs of my own creation. On the website linked below, I go through the different tools and workspaces I used in Fusion and each individual project I made. I also included multiple screenshots of my website and work in Fusion 360. The main obstacle I faced was really my own time management skills and procrastination, like many seniors. If I had to do this project again I would start making and exploring in Fusion earlier. I started in the spring and because of that I did not get to explore all I wanted to, for example, I would have loved to try to use the manufacturing workspace or do more types of animations. Overall, I really enjoyed working on my capstone. I learned many new things about Fusion 360 and I can take these skills to college where I will be majoring in engineering.
Link To The Website I Made: https://sites.google.com/scienceleadership.org/amelia-shamble-capstone/home?authuser=0
Link To Annotated Bibliography: https://docs.google.com/document/d/1blZxydsE70CfNqbANRSn7ZvK-nPz_kB5RbCAjCigKOY/edit?usp=sharing
The stated goal from the onset of my capstone was to create a wooden rowing boat. Shortly after this, I decided on a method of construction known as “lapstrake,” or “clinker,” which uses overlapping planks of wood to create the hull. Between the beginning of the year and Christmas break, my time was primarily spent searching for and collecting lumber. To build the boat, I would need two categories of materials, that being wood for planking and for the frame of the boat. The wood used in the frames was mostly red oak collected from a tree I cut down but also included several other species taken from a pile of firewood. Planking for the hull was made of Long-Leaf Yellow Pine, a structural timber used mainly in houses. Fastenings such as nails and screws were either stainless steel or bronze to prevent corrosion damage. The build began by laying out the keel and creating templates for the ribs. These were pieced together from multiple segments of wood using various complex joints. Tar was used as a bedding agent between all pieces of the boat. Once ribs were assembled, planks could be templated and made. Planking began at the bottom of the boat and built towards the top like shingles on a roof. Seems were laid with cotton fiber to prevent leaking and then riveted together. The boat was thoroughly waterproofed using tar and teak oil. Finally, oars were made of leftover planking material. Measurements are unknown because I did not measure anything.
Link to video: https://youtu.be/7dUwyOqK6NY
Whitehall Rowing & Sail. “Westcoast 11.6 Single Slide Seat Sculling Rowboat.” Whitehall Reproductions, 27 Apr. 2018, https://www.whitehallrow.com/westcoast-11-6-single-slide-seat-sculling-rowboat/. This source is somewhat limited in the scope of information provided. The main reason I saved this was because of its visual content. This source displays multiple images of the Westcoast 11.6 Single Slide Seat Sculling Rowboat. During the research phase of this project, I looked through many sites such as this one to find inspiration. As I began to form a general picture of what I wished to build, I took pieces of information from a wide array of different locations. This helped to shape my vision for what I wanted to make without directly stealing everything about one particular design. Most of this visual browsing was done via Google Images and so was not recorded within my bookmarks.
Sauzedde, Louis. “Steam bending wood without using a steam box.” Youtube, 4 Mar. 2016, https://youtu.be/50uXPPt8-VI. When fitting the planks and gunnels of my boat, I will need to bend them at varying angles. Many of these planks will also have to be twisted simultaneously to fit the complex curve of the hull. As I am using subpar materials, the likelihood of breaking planks or splitting the grain goes up dramatically. To avoid this, I plan on steaming at least some of the planks I put on the boat. The heat and the water from the steam melt the lignin within the planks and allow them to bend. Lignin is an organic polymer that holds plant fibers together. When it cools, the lignin hardens back into place. This video was very helpful as it provides various methods for steaming planks. The plastic bag method shown here is very useful for my purposes as I do not want to buy plywood to construct a steam box or borrow one from someone.
Sauzedde, Louis. “Building the TotalBoat Sport Dory: Episode 12 - The Stem.” Youtube, 17 Dec. 2017, https://youtu.be/SW6UOXqJi_8. One of the most important aspects of this video was the way in which the narrator discusses his process of building the boat. He covers some of the histories of his type of boat including some additional approaches to constructing the ribs. I ended up piecing the ribs together while he used plastic frames. I also did not use a solid bottom. Videos like this can help to expand the way in which you think about your project. A lot of people tend to religiously stick to tutorials and end up not thinking for themselves in any meaningful way whatsoever. In this project, I would like to stay as far away from that type of thinking as possible in order to make something that is wholly my own.
Sauzedde, Louis. “Building the TotalBoat Sport Dory: Episode 21 - The Broadstrakes.” Youtube, 12 Apr. 2018, https://youtu.be/6xpnWQVM2C0. While somewhat similar to source six in the importance of its visual information, this video provides unique and helpful insights into the process of fitting and positioning planking. Here, the narrator shows a strategy for helping the planking to bend at the ends. This part of the bend is particularly stressing on the planks as the fasteners that will go through the wood near the ends put a great deal of strain on the grain of the wood. This can lead to splitting or fracturing of the plank whether through the fastener holes or along the width of the grain due to excessive stiffness.
Sauzedde, Louis. “Building the TotalBoat Sport Dory: Episode 24 - Getting out the Second Binder Strake.” Youtube, 14 Jun. 2018, https://youtu.be/xTQWnOgVZAs This channel and this series in particular have been very helpful in general for figuring out the different steps in making this project. Within this video, the information provided about chamfering and fitting planks has greatly helped me to visualize what will need to be done in order to begin attaching planks to the hull. While what the narrator says is often helpful, equally important to me is what I can observe about his process and the shapes of the planking. You can see in the video the ways he holds the plane and positions the boards. Also of note are things such as the shape of the planking, for example, it is cut in an arc.
Furie, James., Kiely, Benedict., Shaw-Smith, David., Shaw-Smith, Sally. “Hands: Shannon Boat Builder.” Youtube, 1988, https://youtu.be/0meQiENR4zA “Hands” is a 37-episode documentary series that focuses on Irish crafts and heritage. This particular episode shows the process of building a traditional rowing boat interspersed with segments about the history of boatbuilding in Ireland but more specifically that area. While this video was far from comprehensive and mainly served to entertain, it did provide several interesting insights into the practice of boatbuilding. His use of smaller tapered copper tacks to join segments of planking together will be helpful. Also, while most modern resources such as websites or forums show only modern methods this shows older and often more accessible methods of construction. The fasteners I need to use will all need to be made of non-ferrous metals in order to prevent rust. Purchasing screws made from bronze is incredibly expensive while nails are far cheaper. By utilizing these methods, I will be able to save a great deal of money on my project. Waters, Mike. “Construction Methods Lapstrake/Clinker.” Small Trimaran Design, https://smalltridesign.com/Trimaran-Articles/Construction-Methods/Lapstrake-Construction.html Due to their age and obscurity, websites and forums like this one are often quite hard to find. While this is often the case, they can often be treasure troves of knowledge. The demographics of the wooden boat building community are predictably old and not internet savvy. These people, if they can even be found on the internet at all, often tend to flock around archaic forum sites such as this one like neanderthals around a fire. Of course, it is hard to determine credibility here so everything should be considered carefully. Some of these people can be incredibly slow. This specific post explains some of the benefits of the lapstrake method of boatbuilding. These include increased rigidity, internal space, and a classical look. I really chose this design because it looks cool. I also despise traditional boat caulking.
“A Question About Planking.” 7 Jul. 2017. Boat Design, https://www.boatdesign.net/threads/a-question-about-planking.58199/ While the user who began this thread as well as several of the commenters are complete buffoons, there is some useful information to be found here. The comments on this post serve several purposes in the process of my research. One of these is the comments by the user “PAR.” Their points about Lapstrake construction providing additional rolling resistance and stiffness are things that I found quite interesting. The secondary, but just as critical purpose of this source is confirming my preconceived notions about boatbuilding and allowing me to shut out the opinions of other people. Usually, this is not something I have any trouble whatsoever in doing. Even so, it is nice to be encouraged every once and a while.
“Louis Frechette profile - Saved” 27 Jan. 2022. Pinterest, https://www.pinterest.com/lfrechette22/_saved/ Like the first source, Pinterest provided a great deal of inspiration and information which has informed my construction process. Sites such as this one as well as Instagram provide vast quantities of easily accessible diagrams and photographs. While these almost always have been ripped from their context, they are still of great use. Sources such as Pinterest provided the foundation for my brainstorming process. Here, I was able to easily compile them for later use. Another use for this resource is as cheap inspiration. Browsing Pinterest does not feel like work at all and yet it usually results in the benefits of increased motivation and drive. It also keeps my mind focused on the project. This is important due to the sheer scale of it all. Due to the length of the project, it is easy to become sidetracked and waste many weeks doing things that have little to no value such as annotating this bibliography.
Hocker, Frederick, M., Ward, Cheryl A. “The Philosophy of Shipbuilding: Conceptual Approaches to the Study of Wooden Ships.” Texas A&M University Press, 2004. https://books.google.com/books?id=MAxh1P1v7okC&pg=PA77&hl=en#v=onepage&q&f=false In order to balance the above collection of youtube videos and dubiously credible forum posts, I will be including this incredibly dense book on boatbuilding. Sadly, the entire book is not available online for free, but it is not like I would have read the entire thing anyway. Despite this, I did read most of what was available and skimmed the rest. For the purposes of this project, I am not that interested in the specific types of boats discussed. Instead, I am primarily interested in the methods of construction utilized by these ancient shipwrights. For example, their use of sintels as fasteners instead of nails or rivets was interesting and surprising. Also useful was the great number of historical shipwrecks mentioned in passing. Using these names, I could do additional research and find pictures of these vessels. This allowed me to examine the types of joinery used and other methods of construction.