In keeping up the interesting conversations with engineering students carrying out their capstone projects, this week we spoke to Ethan Dreissigacker whose team, as the title points, is tasked with the design and development of a 10 horsepower propulsion system for use in boats. “Walvisstaart” in Dutch means a whale’s tail. The system’s named so because it tries to mimic the movement of a fish’s tail. Since the Netherlands based sponsor Walvisstaart systems wants to make such propulsion systems for large boats plying the water ways of Netherlands they chose the whale’s tail as their name.
So what is Ethan’s team doing?
Ethan’s team is building a fully functioning prototype of the propulsion system albeit on a small scale. The design is inspired by the movement of a fish’s tail, hence the novelty of the undertaking. Not only is the model fully functioning, it is also scalable thus increasing the complexity of the project.
And how did they go about their project?
It’s a little difficult to convey details of this project in only words, for which reason I’ve included here a few pictures which you can follow along to get a better view of what these guys have done.
In the picture below Ethan shows us a model of the fin which they made by rapid prototyping using the 3D printing machine in the machine shop. They first developed a blue print of the fins using a 3D CAD (Computer aided design) software called SolidWorks. SolidWorks provides a file which is then input to one of the 3D printing machines which then builds the rapid prototype model of the design.
Once the rapid prototype is built it is then used for building a silicone mold using which the final components are fashioned, in this case the final fins built of resin and fiberglass are fashioned out of the silicone mold. In the picture below we see the final fins painted bright.
In the following pictures we see the other components of the system, the rotor, the gears and the metal housing frame all of which had been machined in the machine shop from scratch.
So finally since they have successfully built the model what else are they looking for?
Ethan described their aim is “to test as many iterations of the system as possible so that they could look for all the things that could break and fix them.” Given that the machine shop and its instructors are just across the hall, breaking things and fixing them is not a problem hence the freedom to make the system as resilient as possible by stretching it to its limits.
Ethan further describes their goal is “to bring the real system as close as possible to the ideal system designed and modeled on a computer,” the computer model doesn’t account for real world problems in machining hence achieving this is quite an objective.
Well that’s about the whale’s tail. We hope you have enjoyed it and we’ve got a few more related pictures and videos on Facebook, they are even better and we’re sure you’ll enjoy them. Below is the link or visit our Facebook page at Thayer School Machine Shop.
-Pavan R. Yerram