i get the first kit when available!

I like your 'Intermezzo' Jaron - a 1 metre wing fits across my car rear seat nicely!

I recently converted one of the little Multiplex Fox chuck glider to r/c power (like a mini EasyStar) and have to say I like EPP foam for it's 'bouncability' !

I've crashed Depron models and it splits easily, the EPP takes a lot more abuse before damage occurs.

EPP sheet is now available in the UK without too much difficulty and I have just got some 3mm and 6mm sheets.

I may just have to go for the Intermezzo design as the sheets are 1 metre
The icing on the cake would be 'plug n play' wings of different size/design that could fit the one fuselage.
I'm looking at ways to make a spar with servo contacts on it that will 'plug' into a fuselage - makes for easy transportation and interchangeablity of wing(s).

I don't have the luxury of a laser or hot wire cutter, but as you say, a sharp blade, glue and tape is all that is needed for KFm wings.

Nigel.

Jaron,

Looks good .... tried to get a flight in on mine today and had no sucess.... It'll happen soon. Keep us posted on your progress....

Nick

Originally Posted by jaron

One of my main goals of a UAV/FPV/AP platform design is its stable flight characteristics. The flying wings I've built so far are all easy to fly and very stable.

Jaron,
Totally agree. Do you think it would be possible not only to make it stable, but also self-stable? I mean, if you let go the stick, it always comes back to stable flying (like an easy star)?
I don't know much about wing design, but I was wondering if putting the fins at a 45 angle (instead of vertical) would also work like dihedral. Is it worth the attempt or have you tried/learned from something similar?
Cheers,
Luiz

P.S.: I am trying to crash my first UAV wing (so I can built a new one) but I am unable to... I do all kinds of stunts ant equipment tests with it, but it always comes back for more. It was even run over by a car and survived! It has a funny tire mark on it.

mecevans, for now Intermezzo is just a drawing but so far all my designs flew right from the "drawing board" and so I'm (still) confident that it'll fly. However it'll take a while till maiden flight because winter is giving me a hard time here.

Nigel, I considered EPP too but a sheet cost me about 15$/10€ here and then there is all the carbon reinforcement that it'll require. Intermezzo's wing will be more or less wrapped up in reinforced tape and I hope this will give it the desired crash resistance. Luiz' EPP combat wing approach is very interesting in my opinion.
As I already mentioned, the successor of UAV Flying Wing won't be made of Depron (presumably XPS), is more modular and has removable wings. Unfortunately I've got to find somebody who is CNC-cutting the parts for me before I can continue.

Luiz, I can't tell you what exactly the consequences of non-vertical winglets would be but I'd claim that the self-stabilizing effect is marginal. Theoretically you could increase sweep because it has a similar effect as dihedral.
It could be due to the fact that I'm more a heli guy than a fixed wing pilot but I like my planes to go where I point them. As electronics gets smarter, smaller and cheaper we can give our planes a broad range of flight characteristics - from highly sensitive to super stable. Stay tuned!

Jaron, interesting thread and nice looking wings. I'm not into FPV, but have an interest in AP, would like to have a "holiday wing", and:

...the successor of UAV Flying Wing won't be made of Depron (presumably XPS), is more modular and has removable wings...

is just about what I have been thinking about I like the pod design, and assume that getting the propeller away from the trailing edge reduces the noise significantly compared to the more common design with the prop very close to to TE...? I might also consider a front mounted motor with a folder prop, ie. kill the motor and let the prop fold before triggering the camera.

About the airfoil, you seem to be using the KFm foils for the first/intermediate designs, and consider moving to a more conventional foil later on. Do you have any thoughts or experiences with the lifting capability of KFm versus other foils? For convenient transportation I would like my wing to be as big as necessary but a small as possible, so lift is very important. Something like 120cm span and a two part wing, possibly with removable winglets, would be good with regard to transport. My payload would be a digicam weighing in at 200g or so.

knutb, you are right about the noise reducing effect. There is a significant difference between a standard flying wing pusher configuration and the way I put the propeller away from the trailing edge.
On the pro side of a tractor configuration you might have less noise, more agility and more efficiency but these are the reasons why I'm using a pusher:
- no propeller/camera interference
- complete separation of power system (back) and electronics (front)
- more flight stability
- acceptable propeller noise

In my opinion the main advantage of the KFm airfoil is its simplicity and its superiority over a flat foamy wing. I also realized that my KFm planes have a significantly better stall characteristic than other designs but this could also be due to the fact, that all my planes have a very low wing loading. If you are able to cut foam cores, I'd rather go that path - they are definitely more efficient.

Depending on the flight duration you are expecting, you should be alright with a payload of 200 grams on a 120cm KFm wing. My UAV Flying Wing was designed to fly in Swiss wind conditions meaning that I could make it very light. I flew mine with a 120 gram camera and a 200 gram battery and with the right motor this wasn't a problem at all.

Thanks for the input jaron. I don't know if I'm able to cut cores; I haven't tried yet! Guess I have to get some suitable wire and a power supply an give it a try. Using a long sanding block together with templates might work as well, I've seen others doing it, probably here on RC groups, but I can't recall where/when. Otherwise a built-up hybrid balsa/depron design might work as well. Or do as others have done, modify an existing wing to a pod design and make the wing halves detachable. I have built and flown one KFm wing, and it flew well but I didn't try to use it for heavy lifting. But they are definitely easy to build reasonably light and strong.

Jaron,

I ran across this website:

Flyingfoam.com


Check it out they may have something for you...

Nick

Intermezzo 100 is finished and has successfully flown its maiden flight. I'm really impressed!

Details in the Intermezzo 100 blog post.

jaron, I'm a total n00b with some EZ* and stryker flying experience, but a natural tinkerer... so, I started looking into building something on my own and found this thread. Mainly posting to say thank you for posting your design. Great read.

One thing you mentioned is that you were planning to go away from the stepped KF design. Were you planning to go with a symmetrical design, or one with some camber, flat bottom, etc...?

I tried my hand at cutting some pink insulation foam last night, and it cut pretty smoothly. definitely encouraging...
This is just some random profile - just for some cutting fun.

and my little helper

Looking good, frankn7!

The wing will have a modified Sipkill airfoil that is used by the combat wing guys. The coordinates are in the attachment.

Maybe this could be useful for you: Profile 2.2
It's the template printing software that I'm using.

Thank you, I'm using the same program for playing around.

What's your target for minimum speed at level flight? and in your estimation, what do you think your angle of attack would be at normal cruising? I'm using the nasa simulator to look at lift numbers, and was thinking of going with more camber for slow flight conditions <20 mph. Thoughts?

I haven't set a target for minimum speed at level flight nor did I calculate or measure the angle of attack at normal cruising.
I try to layout my planes for stable flight and easy handling. My (pragmatic) approach is to find proven concepts and adapt them so that I can implement them with my (inaccurate) building techniques. That's why I've chosen the modified Sipkill.

I'm no aerodynamics engineer and I can't give you an accurate answer to your question. My knowledge is based on the research I've done for my specific requirements.
In practice the thickness of an airfoil with a broad speed range would be around 9-11%, maybe 12% (depending on the type of airfoil). The airfoil I'm going to use for the UAV successor has a thickness of about 10%. Very thick airfoils have some aerodynamic disadvantages and I would rather keep the wing loading low in your case.

Jaron, thanks for the info. I'm going to take a crack at it with 9.8% thickness (as you had in your file), but a little bit more camber at 3%, and see what happens. Good thing foam is cheap