Hey guys,
I thought I'd start a thread about this years SAE Aerodesign comp, just about this comp, etc..

I'm going to be flying for Gonzaga University's first entry into this competition. We've almost got the design done, and will be building it very shortly, to enter in this years competition.

If you're competing in this comp, or just have comments about it, post here.

--Paul

Paul,

There has been a discussion going on about parts of the SAE Aerodesign in the Weight lifting Competition thread.

We (University of Saskatchewan) are also planning on attending the west competition, just have to make sure we can build the plane in time. Started a wind tunnel model today. I get a few days in March for testing and thats it.

Tyler

Tyler,
That was a good thread, but a little long, and off topic in some areas so thats why I started this new one. Our team is hoping to build the plane right after our spring break. It should go fairly quickly due to my previous building experience.

--Paul

I'll just offer you a few words of unsolicited (and probably unwelcome) advice, based on 7 years' involvement with the UK version of this comp.

Many competitors place too much emphasis on max weight and too little on controllability. When your model is staggering around, you have to be able to guide it, preferably without the need for exceptional flying skills.

Undercarriages are often far too weedy, with high rolling resistance. Make some sturdy tricycle gear with ball-races. It doesn't matter if it's draggy, 'cos you'll only be flying very slowly. Some competitors use undercarriages which are designed to deform on landing, absorbing some of the shock.

Make every effort to prepare the model well in advance of the comp, i.e. test fly it and sort out all of the annoying problems.

Consider your cargo bay. If you are under time pressure, rapid access to the cargo bay will be a huge benefit.

Propellor gearing works a treat, as long as the engineering is simple and rugged.

Don't ever be tempted to compete with a canard.

Keep it as simple as you can.

Springer

Hi Springer; Your advice is certainly welcome, and your ovservations are very good, especially the last one.

Are reduction gears allowed in SAE? I would definately employ one, if they are allowed, because a large, slower-turning prop would be, as you said, a treat for this low-speed competition. There are commercial gears on the market, for large electric motors, and I hope they would be allowed. The class doesn't have to fabricate the radio gear, or the rubber tires, so hopefully they could purchase a reliable reduction gear.

Tell me more about your observations of canards. Too small a canard would be a problem with the low speed and high-loading involved. I was thinking more of a tandem wing design, actually, with the forward wing close to the ground (for obvious reasons) and the aft wing atop a pylon. Variable camber (flaps) on the center section of the aft wing would allow it's lift to be adjusted to match the forward, lower wing while it's in ground effect, and once aloft and at speed the flaps can be reduced.

Here too, canards have not been successful, but both those I saw had too small a canard, in my opinion, for a highly-loaded application.

Stability and control must be achieved, even at the expense of maximum lift.

Are you familiar with the Russian "Ekranoplans?" (Sometimes called the Caspian Sea Monster) Good model for a weight-lifter. I wonder why we haven't seen a commercial cargo-carrier version?

Thankfully due to my previous flying experience, flight controllability is one of my first things I wanted. Also since this is our first year, I just want complete the competition with the minimum weight successfully.

--Paul

Hi Paul; Sounds like a very good approach for your first effort at this competition. Good luck be with you, too!

This is exciting. I may have to make the trip up to Lancaster. Is Pancho Barnes place still open? (just kidding).

When is the western competition?

Added a page to my SAE pages:
http://www.angelfire.com/indie/aerostuff/SAE2003n01.htm

I am curious to know how much groups typically spend on building there airplanes for the competition? Where does the majority of money come from, fundraising?

Tyler

we;ve done some fund raising, and were able to get some funding through the Student Activities council on campus.

--Paul

Tyler- I asked the professor that handled our funding about our budget once. Her answer was don't ask. A lot of our team often buys hardware and electronics out of our own pockets, and we scrounge and beg for scraps of composites from the FutureTruck team on campus (One of their scraps is enough for our whole fuselage).

Last year we guestimated that each competition quality (all-carbon fibre) plane used close to 400 dollars worth of composites alone. Our practice planes used mostly fibreglass, so they are a lot cheaper. Add in a $150 OS engine, six decent quality servos, and all the wirering, connectors, and hardware and the plane we put up at competition probably cost more then 600 bucks.

Many teams are fully sponsored.. see the ads on the Canadian planes in particular..
Others are personally paid for by Dad.
It doesn't hurt to look around for a sponsor or three!

Tyler,

Last year our team spent the equivalent of about $10,000 CAN to get 9 people from Toronto to the Aero Design West event. By far the vast majority of that money was spent on travel, rooms and vehicle rental. Money doesn't go far when $1.00 CAN = 0.65 US. We did not spend an extraordinary amount on the two aircraft; most of our major equipment like the radio and tools were already taken care of. We did however feel it was necessary to finally buy some O.S. engines as our old K&B’s were about done. On our team, each member paid for their own airfare and food and $3000 of the total was financed amongst three members of the team. Some of our funding came through the University from a student funding allocation committee. We were not able to capitalize on a lot of sponsorship, although this year I understand the response is much better. Our sponsors helped us out with donations of money, goods and discounts. We could not have done it without them.

It was definitely worth it. I had a great time at the event as well as the two previous years at the Aero Design East event. Thank you goes to all that are involved with the organization of the event.

Ken Bird
Ryerson Aero Design Team
“Solution”
27.1 lbs

Ken, would it possible to get the coordinates for the Ryerson 45-A airfoil you used? The plane performed surperbly relative to all the others...
to those that didn't see it.. the profile makes the Selig 1223 look flat-bottomed!

Paul,

The Ryerson Aero Design Team is proud of that airfoil. The S45A-3 definitely has a lot of camber and one of the added benefits with that airfoil is the depth that allows one to build a very robust structure at a reasonable weight. Truth be told, I used the Ryerson S45-A3 on the previous Aero Design entries (2000 & 2001 A.D. East) that I designed, but for 2002 I broke from tradition to try the Selig 1223 on “Solution”. Our other team “Freestream” stuck with the S45A-3 airfoil. That is the wingtip of their aircraft that you have on your post. For first timers, they did an excellent job.

I have the co-ordinates for the airfoil, but in all fairness to this year’s team, I will want to check with them first. I’ll let you know when I get an answer.

BTW, the airfoil name comes from the room number of one of the Professors at the University - S45A. The 3 was the third iteration.

Check out their website at: http://www.ryerson.ca/~aircargo/

I guess some teams have money and some don't. We have a whopping $400(Can) at this point. Makes for an expensive trip to the competition. Still have some time to find more money.

Designed your own airfoil, nice. Wish I could do something like that.

Nice lift at 27.1lbs!

We were lucky to pick up some money through the school, but since its our first year, finding sponsors is difficult. We now are up to $1300 for plane and entry. Travel will come from our own pockets.

--Paul

I'm always amazed at how far some teams come from just for this event. There's been teams from Brazil, Australia, the east coast, and of course all the Canadian teams. Davis is only 6 hours away, and it is great on Sunday to pack up and make it back the same day.

Course, we kinda have to, since the weekend of competition is our first weekend of FINALS, and there's always a final on Monday.

Flew my 2003 rules plane today twice.
Easy flier.
1080 sq. in.
8-1/4#
OS 61
TF 14x4 prop.
Rudder, elevator, motor , flap.
Building the weight box now.

Hi Paul; Nice looking aeroplane!

However, I predict that a tandem-wing design will prove superior under the span-limit-only rule. You get twice the wing area, lots of pitch stability, and ground effect on the forward (lower) wing to assist the rotation when heavily loaded.

I didn't say that a tandem-wing design will win this year's event, but given time for development I predict that a design of that type will establish a record that will mandate that future competitors under this rule must employ a similar design, in order to be competitive.

Just as pattern airplanes tend to all look alike, once the tandem-wing is fully developed for this event, I expect to see several in the ensuing years, until once again the rule must be changed to avoid stagnation of the design exercise.

Well, the rules are written so that the airplane specs can change year-to-year.

I expect a "this design always works" won't be possible year-to-year if the specs are cleverly altered.
(Sneaky minds at work, even as we speak!)
.
It is a drag to see the same design year after year win.... FAI Team Racing reached that point many years ago. ALL the planes today are flying wings.. and usually ARF's from Russia. Only incredibly expensive engines make the difference in competition.
.
This year's East Coast event has a slew of entries....
http://www.sae.org/students/aeroeast.htm
.
And based on what I've seen out here from some of those teams, the shapes WILL be different!
That's where the 2004 specs will be released.
.
There's a trade-off between how much wing you can have and still get the motor to fly it off the ground in 200 feet!
If it can't it can't fly,it can't win!

Ralph- not so sure about a tandem wing config. You do get twice the wing area, but the rear wing will see lots of bad air from the front wing, so I'm not sure how much extra lift that will produce. Also, in order to strengthen the fuselage you might have to add too much weight. The last few years we used a light carbon tube for our empennage and the tail vibrated like crazy. To fix it, this year we added almost a pound worth of carbon.

Biplanes are a good solution, but again you have interefence cutting the lift and lots of extra drag and weight. I guess it's just up to the teams to decide whether to play it safe or try one of these configurations.

Thud_Driver just alerted me to this thread and the other one that was getting so long. Thud_Driver has been our Air Boss for the last couple years in Lancaster.

I'm glad to see that some teams have found RCU and are using it for these technical discussions. We set-up the SAE Aero Design Forum with the hope that teams would use it for this purpose, but if there's good dialogue happening here, that's awesome.

Due to work and school commitments, I'm not taking such a strong role in the contest this year. Larry Stephens is the CD, and Marilyn Clendinen is the Chief Judge. Next year the contest is moving to Ft. Worth, still sponsored by Lockheed Martin, and likely to be held at the Ft. Worth Thunderbirds field. If it's there, you'd better be able to make it around the patch or else you could end up in a lake! MiragePilot will play a leading role in the contest next year.

I'm one of those devious minds mentioned by Tall Paul in one of his previous posts. The rules are now set-up to enable changes from year-to-year that will force redesign of the aircraft. This year there's a 72" span limit, next year we'll choose a minimum span that will render this years' aircraft unusable.

David Eichstedt

AIAA has had a wingspan only limit for a number of years, and is not dominated by any particular configuration other than '"normal".
Their rules are more complex, in requiring multiple tasks per flight, and altering the configuration of the ballast.
There's all kinds of ways to get lift, but along with lift comes drag, and that limited power output can do just so much.

Tandem wings don't interfere with each other if they're separated by more than two chords longitudanaly and more than one chord vertically.

The front wing is close to the ground, and the rear wing is up on a pylon. The frong wing will gain lift from ground effect, to assist getting off the ground in less than 200 ft. The aft wing has flaps, to gain added lift at low speeds.

With more wing area, an airfoil can be chosen with a better lift-drag ratio, and still lift more weight than an airplane with less wing area and a more drag because of its high-lift airfoil. Fringe benefits, you might say. More lift and less drag, too.

Here's a link to a drawing of my canard, which is designed for a distance competition. Not the same as weight lifting, of course, although ROG with 1/2 gallon of fuel is required. That's over three pounds, plus the weight of the airplane.

For weight lifting, I would make the "canard" almost as big as the main wing, and set it at the bottom of the fuselage. The landing gear would be much shorter (two sprung axles with skate wheels for the mains, and a short steerable nose wheel). This puts the forward wing close enough to the pavement for good ground effect.

Instead of the pusher, I would place the engine on the front of the pylon, above the fuselage. This will put air over the main wing, for lift to match the canard in ground effect.

"Flaps" on both wings work as elevator on the front wing and flaps on the aft wing. Steering is by spoilers on the outer main wing panels, which have dihedral.

Here's the plan view:

http://www.rcuniverse.com/gallery/sh...t=1&thecat=500

And here's the profile:

http://www.rcuniverse.com/gallery/sh...sort=1&thecat=