grubbyjeans

Here is an EXCELLENT source for 3-views:

[link=http://www.suurland.com/]Click on 'Blueprints'[/link]

calvino

eh, sounds like UBER FAST ROLL RATES, not what would seem scale IMO, heck, it is 4 less hinges to fail[8D]

cubnpede82

Hey all,
new to home built foam board stuff. Just got 3 sheets of elmers papered foam board to give it a try. I like the DR-1 by the way. ! .
I plan to make an SE5 , the e-flite slow flyer inspired me and I got dragged along to the craft store the other day so I decided to find a few things I could use to fly and this was there. I plan to make only a profile fuselage then reinforce with 1/8" bass wood on the tail 2/3 and a stick that will be part of the motor mounting system on the front 2/3, I may make pieces that stick to the sides of the fuse. to have a profile from top/bottom. still not sure there. Any advice on stick mounting a motor would be great. Also is there need to add down and right thrust? and about how much? I'm not sure it's going to work but I'm going to try to get some airfoil into the wing by bending the foam slighty. Is having airfoil really necessary for a light foamy? Any advice on this project or help would be greatly appreciated.

Thanks to all for this wonderful website.

Isaiah
[email protected]

P.S. Here's my first balsa plane, it's still a hangar queen as I'm a fairly NOOB pilot of about 2 yrs.

Pecanpatch

Hey,
I think the down and right thrust helps for high powered 3D models but not so much for a trainer type noob plane.

Nice looking tiger moth? I take it that is an arf?

No , you dont have to have an airfoil....... It takes a lot of flying experience just to tell the diffference between a flat wing and one with an airfoil.

j.m.

Um....


No it doesn't. A properly balanced plane with an airfoil will not fly upside down. It will require a bunch of up elevator. Most foam planes however, are what is called a "cg" flyer. This means that the plane gets its lift by having the cg farther back than it needs to be, so the wing has a positive angle of attack no mater what position the plane is in. This will keep it in the air, but by default the airplane will not be stable because the "wing" is very close to stalling.

Anybody will notice the difference an airfoil makes, as it will increase speed (less drag) and run times (more efficient) by requiring a lower throttle setting to maintain level flight. The airplane will also turn much better, and it will most certainly climb faster, as the drag doesn't increase on a proper airfoil quite like it does on a barn door. If you don't believe me, then just look at the drag curves for different aircraft. I guarantee you that parasite drag increases at a much faster rate for a fighter type aircraft with a nearly flat wing, than for a Cessna or Lancair.

Pecanpatch

J.M.
Your crazy about a properly balanced plane with a airfoil wont fly upside down without a bunch of up elevator.(I think you meant down)
Thats how the IMAC guys will tell you to balance the plane. Till you need no elevator trim either way in upright or inverted flight.

I have the report in my hand were Auburn university did a Wind tunnel test on a flat plate and it is suprisingly effiecent.
The envelopes on these planes are much smaller than what you describe as well.

The airfoil planes do fly better. We have a Hobby Lobby Super Zoom. Great flying airplane. Turns well.But it was $90.

My flipper cost me about $20 with CF rods.

Anyway this is the Flat foam forum for noobs and inexpensive fun planes.

KISS= Keep it simple stupid

calvino

well, I can see with a flat wing, all it gets lift from is the angle of it, sooooo, if you are inverted, it doesn't care[8D]

j.m.

i know what you all are thinking, and it does make sense. All that i am saying is that is is much more efficient to fly with an airfoil instead of a flat plate. The IMAC airplanes you are thinking of have a semi or fully symmetrical "airfoil". A fully symmetrical "airfoil" Isn't an airfoil at all. It is simple a teardrop shaped wing. (the most efficient shape under the speed of sound). This is why an airfoil is so much more efficient. One, because a flat bottom wing is exactly half of a teardrop shape, so it is almost as efficient. And two, it doesn't require an aft CG to get it's lift, so the top speed of the craft is automatically increased.

$20 for a foamie is mighty expensive. I built one for about $8, and i am working of converting this right now:
http://www3.towerhobbies.com/cgi-bin...?&I=LXLFF9&P=7

That's all i'll need besides radio gear, which i can get for a total RTF price of $60. A little sanding work is all that's required. (the wing is already surprisingly stiff).

team3d

Hey guys i am back,

I have a question though and something i think people should try.
I have been having the need for speed latley and been
looking for a cure. But i wanted a hotliner 60" size plane.
I have been planning and thinking how i am going to do this, i wondering
what servos i should use on this type of plane, i am designing something that looks like the Micro flash http://www.espritmodel.com/index.asp...OD&ProdID=2088
when i am finish i will post pictures.....
I also wanna know if anyone done this before and i would love to see people
give this size plane a try, i wanna see what you guys can come up with.....


chuck

theradioflyer

Wow, this is a pretty cool thread. I've never check it out before so I've got a lot of reading to do! I love flying depron made planes, the glide slope isn't very good but the teaching vrs $$ is awesome. I learned 3D with foam and then drew up my own planes. My avatar is the first I did and it flew well. The second was a Yak I drew and then painted with acrylic paint out of an Estes Aztec airbrush. To date I designed and flown four flat foam models which I used as a stepping stone to create my own design balsa built-up 3D design which I flew super bowl Sunday and it flew awesome.

God Bless All, I have some reading to do. Here's a video of my 6mm depron Yak 54:

http://www.youtube.com/watch?v=6uXUAzGg2sU

Jay

j.m.

i think you mean the glide ratio, but i get the point.

Actually, because of their extreme light weight, foam airplanes can have some of the all around best glide ratio's of any plane out there. (they are going to be gliders of course)

Foam airplanes are EXTREMELY cheap. I can build them for $1.33 a piece for materials only. (6 sheets of EPS foam for $8)


Instead of using expensive carbon to stiffen things up, you guys should try to use some monokote. It makes a world of difference, and barely adds any weight.

calvino

eh, wouldn't the heat to appy it melt the foam?????????[&:], sounds cool though, thought of it, HEY, it prob does about the same as tapin, plus it looks better[8D]

j.m.

i have a hangar 9 heat iron, and i use it on about 3.5 (that's a little more than halfway) Yes, if you do use it on full heat it will melt the foam.

Monokote is actually better than tape, because it shrinks a little as it is applied. It really stiffens things up.

Pecanpatch

J.M.
I dont want to get in a pi$$in match with you........
but again your wrong.

Foamy type airplanes do not have good glide ratios.

They have no mass.

Mass is energy.

The are typically draggy with servoes and crap hangin out in the breeze.

They are like ultralight airplanes (I have owned 3)

They basically fly like a wiffle ball.

Low mass, high drag

crappy glide ratio

On another note Monocote reenforcemant would never hold up to my snap roll button and other crazy manuevers.

http://www.youtube.com/watch?v=KWDRz2Q3DVY

tclaridge

Drag has two components: parasitic, and form. There is also component of drag due to lift. More weight requires the wing to generate more lift which causes more induced drag. A lighter aircraft will actually generate LESS induced drag.

So foamies may be a little dragier than a clean built-up model, but at less than 50 mph, it doesn't make much difference. The parasitic drag difference between a foam surface and covering is probably not measurable. Frankly, the aerodynamic characteristics of a flat plate airfoil are really pretty good at low speeds also.

I have the Ikarus Su-27 XXL with a wing load of about 6oz/sq ft. It glides real nice. This plane inspired me to build another project, and I am almost finished with the P-13a. If you love to build and fly, and you don't care to go much above 50 mph, flat foam is hard to beat!

Pecanpatch

Glide ratio, also called, Lift-to-drag ratio, glide number, or finesse, is an aviation term that refers to the distance an aircraft will move forward for any given amount of lost altitude (the cotangent of the downward angle). Alternatively it is also the forward speed divided by sink speed (unpowered aircraft):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~
Its all about how far forward you get for each foot of altitude you loose.

I garantee my Nitro 5 lb PT-40 trainer would have a heck of a lot better glide ratio than any of my 17 oz foamies

j.m.

Well THAT's your problem!

A 17 oz foamie is no light weight aircraft at all. (and it's probably a 3d plane too)

I am almost finished with a foam glider i am converting to rc, and so far the AUW is 7oz even (54" wingspan)

All i need to add now are pushrods and control horns.

When i threw this plane with a light toss in my front yard, it went all the way across mine, and halfway across my neighbor's.

we both have 1 acre lots.

You tell me that 150 feet of gliding from a light toss isn't a good glide ratio?

I think you need to learn how to build lighter, and learn what airplanes are designed to do.



A p-40 was designed when they didn't have high horsepower engines, so the plane has very large wings that make alot of lift at slow speeds.

A 3d aerobat is designed with a 300+ horsepower motor in half the size of the p-40's engine. (believe me, 300 ponies of an airplane is alot)
Aerobatic planes aren't designed to glide. They are supposed to go really fast.

Pecanpatch

J.M.,
I bow to you.... You know it all with your 1 year flight experience (in your profile)

Now back to my paying job...... (working on U.A.V.'s)



Check out my photo gallery to see what I've been up to for the last 35 years

j.m.

one year flying experience with RC planes doesn't mean anything.

I am in my third year of an Aerospace engineering program, and the second and third years focus mainly on gliders. I am not saying that you don't know anything. I am simply saying that foam gliders are alot better than you think.

Here's a link of the plane i am converting:
http://www3.towerhobbies.com/cgi-bin...&I=LXLFF9&P=ML
if you think you might want to try it, then i will pm you with tips and tricks on how to do it.

tclaridge

I would bet that aspect ratio (drives planform efficiency) is a bigger driver than weight on the glide ratio. I have two planes of the same size, one in profile flat foam, one built up. The flight characteristics I see can be explained by wing loading. I think the flat foamies have a tendency to glide like a "leaf in the wind" because they are so lightly loaded, but thats what makes them fun to fly. High thrust-to-weight, low wing load, easy to repair and build, and cheap. What's not to like!

Pecanpatch

J.M.
Where I live........ in the middle of about 130 acres (no trees), there is always some wind. So anything under 15 ounces just gets blown all to hell.
We all gravitated to larger heavier 400 sized models.

The really light stuff is considered indoor as far as I'm concerned. I dont do indoor.
I'm not interested in converting toy-r-us gliders into RC planes. (it's not in the context of this forum)
Yes I'm a 3D flyer. You asked that Like it was a bad thing.

I'm a Machinist/autocad designer at a Major US airline. Many young engineering co-ops have come to us to ask "how can we repair this? We tell them. They have no practical experience to know any better. Then they consult Boeing or whoever to see if its okay to do that. Then they write the repair and pretty much get all the credit. When the part comes back to us at least we know it is a tangible repair. Something that is capable of achieving with the equipment in-house.

This is called teamwork. Everyone has to get along and try to work together. Maybe they teach that in the 4th or 5th year.

Pecanpatch

Here is my latest video.......
a friend edited this for me......... he did good!
The winds were 6 -7 that day and I was at a flying field where I was limited to a 300' box to fly in sort of.........

But I thought it turned out pretty good....... The Chile was good that day too.

FFF at its finest here!

http://www.youtube.com/watch?v=ZWQszCuzHIw

Off Topic:
Here is my latest Ultralight Video....... Windier than }{ell that day.....
Thats me with the airshow smoke..........

http://www.youtube.com/watch?v=xB8DdVG5Q54

jumper666

Pecanpatch, is that you at the sticks and catching? Good video and choice of music.

Pecanpatch

Yes it's me
This was at the Annual Chile-Fly in McDonough GA

ntjp2005

Don’t be too hard on him Marko. In time he will grow up to be an outstanding fff builder. I am over 40 and still not grown up….. Just ask my wife LOL…. I still live by “NEVER GROW UP” And the best one…. Your only as old as you think you are… I kind of like being 15 my self…. AND yea I knew it all then too. I was actually really smart once>>>> but then I got married and found out just how dumb I was. All he needs is a good wife.

LT