If you were to attach a motor to an umbrella which way would you face it? With the umbrella in the up position and the prop facing down like it's diving, the motor would want to go forward but the air going into the umbrella would try to make the umbrella go up right? I would think that filling the umbrella with air would be the only way it would be controllable. If the motor were facing the climb position it would be pretty much uncontrollable right? Not that any umbrella flying around would be!

Any thoughts on this?

HaHa, you must have too much time on your hands, with all the kits available, why do you want an rc unbrella, I think it's a disaster waiting to happen.
Joe

It wouldnt work cuz the umbrella would want to spin with the engine, if planes didnt have rudders they would spin too. Am i rite?

NMTR13

its been done here in the uk, ill see if i can find pics, it works aswell!!

partly right , most aircraft in a normal configuration need some form of vertical surface behind the c/g for directional stability, otherwise they would spin.
however, there are lots of tailless models out there including flying wings with no fins.

do a search on 'horten brothers'

I would appreciate them pictures just to get some ideas. Any other thoughts on the subject?

First, It's the wings that keep a plane from spinning

Second, let's, for a moment, entertain the notion that you were going to attach an engine to an umbrella (I'm assuming you mean at the handle). If the prop is facing away from the opened umbrella (Blowing it's prop-wash into it) AND assuming that you have somehow managed to prevent the umbrella from spinning (Which it WILL try to do), The umbrella will go in the direction that the prop is pulling it, not vise versa.

Why?

For every action, there is an equal and opposite reaction, right? (This reminds me of the old cartoon trick of mounting an electric fan to the back of a sail boat.) As the engine blows air backward, it propels itself forward, but the air that it is moving, is (theoretically) being caught by the umbrella. So in a perfect world, the umbrella will not move. In other words, let's say the engine is blowing 5 psi of air back. This means that the umbrella is getting hit with 5 psi, so they will cancel each other out.

But this is not a perfect world, and some of the prop-wash is bound to miss the umbrella, so the prop will win the contest,

But now, of course, weight comes into play. Is the remaining force of the prop enough to overcome gravity?

I love s**t like this!

Now that's a good answer....I'm still waitng on cab to post some pictures of the flying umbrella adn we shall see how they set it up

If you put the engine on top, pulling up, it will probably fly. I'm curious how you plan to steer it, though. The weight of the handle and the shape of the parasol would probably make it really stable, but directional control sounds like a problem.

if you put it on top of the umbrella, pulling up would blow the air onto the wrong side of the umbrella. If I did that it would be difficult to control, but if I put say 4 flaps about 8 inches by 8 inches on every other side of an 8 sided umbrella I could get "rudder" and "elevator" movements in hoa flying, which is a good start. but how to get the umbrella to stop the spinning motion as mentioned above

different thought
maybe a norvel 15 with an 8x4 prop.....a hole 9 inches in diameter cut directly out of the top of the umbrella so the blade could act as the nose of the umbrella and still let prop blast move over balsa or coroplast surfaces at the bottom of the umbrella which would act as elevator and rudder....or stabalizers Which would mean that...hmmm...

I hope you're not seriously considering this.

My thoughts exactly.[]

I think you NEED to build this. That way, people can fly on rainy days!

Joe,

Don't listen to the nay-sayers. Who would of thought a 2 foot by 2 foot piece of flat plastic board would ever fly!!! After all their is no air foil, right.

I think you and everyone else already know that there is a lot more to it than an umbrella and a motor, and that is what you need to figure out. I am sure there are some here that can help you do that.

TW

ok, i have tried to contact the guy that built it but as yet no reply, but its only been a day and hes on a british forum that doesnt get visited that often so give it time.
i may yet find the magazine that i saw it in( yeah, right, in that mess?!)..

from what i remember, he used a normal sized adult umbrella and a small profile fuselage with a fin and rudder (large rudder) at the back as normal, no tailplane/elevator.

the motor i believ would have been mounted with a little upthrust and this gave power for forward flight and the elevator controlat the same time.

(power up for climb, mid throttle for cruise, idle for descent, you know what i mean.)

the umbrella had sort of an airfoil ( think of an umbrella cross section, its a heavily undercambered skin right, not efficient , not pretty but an airfoil nontheless.

i remember that there had to be a hole cut in the top middle of the umbrella skin as there was too mush 'lift' being created, after this mod i believe it flew well, ill draw up a diagram from memory, bear with me.....

why not, i have seen wierder things fly, besides this is 'proven' !!

Good luck with your project, hope your AMA is up to date

Check with Wiley Coyote, he probably knows the answer to this one!

good drawing, not exactly the thought I was looking for but this one might be a little better....how does the air get from the motor to the umbrella though if it's aimed straight back....and even down a smudge? Thanks cab for your effort...I think that should get some minds working!

the umbrella is a wing in that example, forget air going to it...

heres a forgotten fact.. a porp dosen't blow the plane forwards, it pulls it forwards, a prop is a spinning wing, the "wind" is a by product. in other terms, if you mount the engine to the ground, theres no way prop wash can get around it, but it'll still pull with all its might. the difference being in flight the air is moving. on the ground its sitting in its own turbulence.

mounting the engine ON the top of the umbrella wont hurt your pulling power one little bit. might hurt it a few seconds later when it hits the deck tho LOL

do it as in the picture and use the tlar method ( that looks about right) and it will fly

that thing of yours reminds me of the flying parafoil wings for combat. same set up, but swap the umbrella for a parafoil kite. only they had a shed load of down thrust

in the rcme just for fun column phil, i remember.

maybe you would want downthrust, i dunno, i just drew the pic from memory.

somebody try it!!!

if no-one does i might have to!!!

Ok now I got a working flying umbrella going, now to specifics.....First off is which motor to use, or does it even matter....I like the norvel 25 for my PBF so I think I may buy another one of them to have. I'm going to also take the coroplast idea from the pbf and make a profile fuse out of it with one hell of a rudder. Does weight make a difference? CG on the umbrella? really all I need is a rudder servo and a throttle servo right? the elevator is built into the lift of the motor and umbrella combo. When it DOES fly and I add full throttle will the fuse be ahead of the umbrella or will the umbrella shaft stay perpendicular to the ground? Adding to that question is a full throttle loop possible?

Post pictures when you get it flying, I got to see this, oh, and wear a hard hat

have you ever seen an umbrella turn inside out with a strong wind......dont push your luck eh!

coro fuse is a good idea. you will not get it right on first time and it will have to take knocks.
throttle up and the fuse will move forward pulling the brolly with it, i have decided to make one aswell!
i would have thought the c/g would be about 1/3rd way back from the brolly leading edge( ? )

good luck, get building!