In 2013 our hull was made by skewering expanded polystyrene (eps) discs onto a spindle, fairing it to the desired profile and fiberglassing over the form. It was pretty straightforward, but time intensive. Some of our eps had come from cellofoam via a roofing contractor we knew. We'd heard they could make big, intricate shapes. If we had the financial resources but limited time, might we be able to work with cellofoam to make our fiberglassing form? We decided to find out. Hence, our trip to cellofoam's plant in Winchester, Virginia, where Plant Manager Rick McMahon gave us a guided tour. Our conclusion: Yes! Cellofoam could be a valuable resource for our submarine team. Not only could they make a shape to the size and dimensions we needed, but they could mark centers or ship it with a center-axis spindle in place. Thank you for the great visit, Mr. McMahon and the cellofoam team!
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One of our goals is to learn how to lay down fiberglass more proficiently. Three new team members--Nisha, Scarlett and Liam--who did not work on the previous sub came over to the Carts' house and learned about types of fiberglass and types of resin. We worked on sample squares and tried our hand at making bulkheads by pinching a "wet" strip of fiberglass. Here are our results:
What a great day! The hull team came by in two groups and we were able to experiment with heat forming acrylic. Our first efforts included putting a simple bend in small acrylic samples. Everyone got a turn at clamping his/her sample in a vice and heating the piece with a heat gun. We ended up with some interesting shapes. Then we tried our hand at forming complex curves by trying to mold a piece of acrylic to a metal bowl. We experimented with three techniques: heat gun, drape forming, and vacuum forming. We clearly need to do more testing--possibly consult with someone who has more experience--but we learned a lot about the importance of temperature control, good clamping, team work, and problem solving. Here are some photos of the team at work.
Fueled by their desire to propel the sub with a jet of water, the propulsion team hit on the idea of dissecting a jet ski. Our fiberglass mentor, Mr. Whitley, conveniently knew of a used one available for this purpose. (Thank you, Mr. W!) Mr. Riz picked it up, and the propulsion team set to work. Below are photos of the team taking the jet ski apart in their quest to understand how it worked. Some of the lessons learned are: it's harder than you think to take apart a jet ski; a jet ski propulsion system is likely considered a prop design because it has radiating blades (we're hoping to enter the non-propeller category); it might be difficult for a human-powered vehicle to supply the rpm necessary for this system to work well.
Today we met with Mr. Dave Whitley, owner of Fusion Fiber Marine. We discussed how the last hull was constructed, the problems we had, and ways to avoid them in this year's construction. Boy, did we learn a lot! Today at our meeting we made lots of very important decisions. 1. the name of the submarine The Nautilus 2. one person or two person submarine One person 3. to vote on propeller and non-propeller or to let the propulsion team decide let the propulsion team decide We also took some Groups pictures that will be uploaded to the website soon! There are also some changes to the leads and assistant leads of the submarine component teams. |
AuthorSMrs. Carts, hull advisor Archives
November 2015
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