Design/Build/Fly @ Rensselaer

As expected, the last couple weeks of the fall semester, along with the holidays, have not allowed us to make as much progress on the plane as we would have liked. Nevertheless, we have managed to complete most of the detailed design and plan to have it finished by January 17th. After that, we will spend a week on any last-minute issues that need to be addressed before starting the build phase on the 24th. The work we have done so far has been challenging and sometimes frustrating, but very rewarding. We have dealt with several changes in the center of gravity (which required major fuselage redesigns); different airfoil choices; disagreements over the use of elevators; and changing propulsion and electronics gear. The only major design tasks remaining are to design the landing gear and its mounting points, analyze the CAD models for strength/weight optimization (using COSMOS and ABACUS), and integrate the individual teams' work into a single result.

It has been fascinating to see the overall design evolve. We have developed about a dozen CAD models for the fuselage alone, each one different and more refined than the last. Starting from a simple box-like shape, we have gradually molded the design into something that meets the structural, aerodynamic, performance, and payload needs of the mission profile. The next two weeks will be interesting: we will really need to test the concept of web-based teamwork in order to finish the design before the start of the semester, and several team leaders will be leaving for co-op positions. However, we are all confident in our ability to successfully complete the project; we have already accomplished much more than we could have dreamed of in years past. Look for more updates as we finish the design and start fabrication.

Have a safe and happy New Year!

So we've made a lot of progress since our last post, mainly due to the nightly meetings held by each of the sub-groups. We've finished a lot of the structural and component selection aspects of the design, and feel like we're generally in good shape. However, the final two weeks of the semester are bringing our work to a crawl because of all the exams, projects, and general chaos familiar to every engineering student. We won't be able to finish the design before we leave for winter break, but we now have a new tool to collaborate from home: Teamcenter. This is a team integration system developed by UGS Corp. which allows for the management of data, documents, announcements, inter-team tasks, and more in a customizable, browser-based interface. This has already eliminated the need for endless emails and keeping track of who has what version of this-or-that CAD file, and we hope that it will allow us to actually get work done without having face-to-face meetings. Does anyone out there have any experience with such a system? We'd love to get some first-hand advice on how to utilize this resource most effectively.

Hi everyone, I hope you had a nice Thanksgiving. I'm finally getting around to posting our first progress update, and we've gotten a lot done! I'd like to start by thanking Mark Watkins and Tom Brownell for helping to secure a generous donation from Globalspec, as well as Chris Leonard for setting up this blog. Both contributions will be enormously helpful for us as we go about this design project.

This year's DBF team has been the most productive in recent memory. We started out with various small-group conceptual brainstorming exercises to get the creative juices flowing, resulting in about a dozen basic aircraft designs ranging from the conventional to the more radical. We then discussed what we had done and used factor-of-merit charts (useful, albeit somewhat unpleasant tools for quantifying what makes one choice better than another) to narrow the numerous concepts down to three options for the preliminary design phase. These consisted of a high-wing twin-prop model resembling a C-130; a low-wing single-prop puller; and a twin-prop canard (an airplane with the main wing in the rear and the "tail" in front).

Each of the designs was further developed by separate groups over the course of several weeks, with the goal of determining component types and locations, performing calculations and analyses, and producing scaled drawings. Finally, the three preliminary designs were presented to the entire team, cardboard mockups were built and flown/dropped off a fifth-story balcony, and a final design was chosen (again relying on discussions and FOMs).

Last week, we began the detailed design phase using the winning concept, a twin-prop canard. Team members broke into groups for each part of the design: the Lifting Surfaces group, which is designing the wing and canard; the Propulsion and Electronics group, which is selecting motors, propellers, batteries, control servos, transmitters, and wiring; the Fuselage group, which is responsible for much of the aircraft structure, payload systems, landing gear, and integration issues; the Dynamics group, which performs many of the calculations needed to make this thing fly; and the Research group, which will do everything from experimenting with carbon fiber construction, to component prototyping and drop-testing. Additionally, the leaders of these groups make up the Integration group, which will meet each week to ensure that everyone is communicating and working together.

We'll post updates (hopefully at least once a week) as we continue through the process, and we welcome advice, discussion, and questions from CR4 users – feel free to post comments here or PM me.