AIAA Contest Build Thread - Manhattan College

[Mikeyburger240]

I am changing the name of the original thread to better represent what my group is working on as part of AIAA. We are working on a airplane design that we will build and I will fly this coming April. We have to build a airplane that will complete three different missions.

The first mission is to just do a circuit with no payload. The second mission is to carry 6-10 soft balls inside the fuselage of the plane. The third mission will be to carry bats weighing 1.3 pounds each on the outside of the fuselage. We would like to carry at least five, but more would be good. We are given four chances to complete the three different missions and we cannot change batteries between between each of the different missions

The basic frame shape is shown in the attachments. The first two softballs will be carried single file, and the remaining possible eight will be two by two after that. The bats, we are assuming, will be strapped to the bottom of the fuse and possibly under the wings. The shape of the rounded fuselage will be given by a type of frame around the structure part. The entire length will have two carbon fiber bars running the length to give strength. The wings will come apart in two. Each side will be strapped onto the body. Two more pieces of carbon fiber will run through the wing into the body.

As for the electronics, I am really unsure of what we need. We are restricted to using NiCad and NiMN batteries and they cannot weigh more than 4 pounds. Also, they can not have more than 40 amps of current draw. I am not sure about the voltage and how this would be determined. The motor we project will be be required to provide up to 8lbs of thrust. I am not sure if this is enough or too much. The TX will be a DX7, but I am undecided on what kind of RX we will be using.

This is a link to the rules.
http://www.aiaadbf.org/2010_files/2010_rules.htm

I really appreciate any input, and once we actually start to build it I will keep the thread regularly updated with ideas.

Mike

[Aero Ace Ace]

Deleted-no longer relevant.

[Deuce]

School project?

You could try playing with MotoCalc (http://www.motocalc.com/) .

James

[Aero Ace Ace]

You could probably get 22 sub-c cells into a pack around 4 lbs. That would be 26.4v nominal. You can still get 1000 watts if you are careful not to exceed 40 amps. I would start looking at 400 kv outrunners and adjust the prop to keep the amps in check. You might even want something slower with a bigger prop, since you aren't after speed as much as thrust.

It looks like you are required to set up the radio fail-safe to force the aircraft to violently crash if radio contact is lost.

"Radio fail-safe check. All aircraft radios must have a fail-safe mode that is automatically selected during loss of transmit signal. The fail-safe will be demonstrated on the ground by switching off the transmit radio. During fail safe the aircraft receiver must select:
Throttle closed
Full up elevator
Full right rudder
Full right (or left) aileron
Full Flaps down (if so equipped)"

That should be fun with 5 baseball bats. I guess you wouldn't want a lipo battery on board a crash like that anyway.

[MIT KID]

Hi Mike, welcome to the world of design build fly. I've been involved for 5 years now. I'm glad to see that you're interested, but being a competition I would strongly recommend not disclosing aspects of your design in a public forum. Teams typically take every measure possible to ensure details of the design remain secret until the competition weekend. Perhaps you guys are not interested in all out competition, but better safe than sorry.

There is a site dedicated to dbf, where you can gain a lot of info on past setups, and find previous design reports.

http://terrabreak.org/

Best of luck, and feel free to PM me with any questions

-Adam

[plasticjoe]

I got a call from the University of Dayton on the same project .... pretty cool

[Mikeyburger240]

Hi everyone,

Aero, I like the idea of the sub c cells. They seem like a good option. I don't really know a lot about motors. Would a 400kv one be able to produce enough lift? I know that changing the prop size can change the thrust it is able to produce. And yea I did notice the fail safe positions, too bad, but I guess it would be better to make it crash.

MIT-Kid, well at first we were going to be kind of secretive, but this is out first year and we have agreed that we will be happy if we can just get this thing to fly. So maybe next year we will be a little more professional. Thank you for the site. I looked at it and some of the info will be helpful.

We will be starting to cut the wood for the frame this weekend. Also, what would be a good material to cover the plane. I was thinking of partially covering the wings with balsa, and then cover all of it with wrap as well. For the body we are still undecided between using really thin balsa, like 1/32, or just to wrap the body. What do you think?

Thanks
Mike

[CAFplanekid]

Mike,

I would suggest reading past reports from competition teams (the top three from competition are available at www.aiaadbf.org ) to get ideas for construction methods and even design processes.

Jonathan