GreenAce92's Sailplane Projects thread

[GreenAce92]

Well im just going to start off this thread here, so if people do follow my builds it will be easier to follow(as suggested by a few persons)

Anyways currently im doing my first fiberglass dlg bird, but im now taking more interest in the F3J series sailplanes. Im the thermal guy so i figured i'd post here, as i am not any good hills/mountains so no slope or DS'ing for me.

Im in the works of designing a mini F3J sailplane a 42in span with detachable wings. First prototype will not be fiberglassed (i have to get more cloth lol) but yeah it will be launched by a small like say 20ft surgical tube, and only 10ft of rope or so, it will be just a pure height launch by Strength not like a slow kite start. At least im hoping anyways, and i also plan on making the plane have detachable wings. I will have the normal long skinny aerodynamic/sleek etc... fuse plan, and then there will be slits in it, for my (glassed popsicle) which will inter-lap(ill have 4 of them total) so i have 2 main joining points, where i will have pins go through and join the two wings. It will have a single servo aileron system. Will be slightly heavy on the loading side im expecting. But yeah for flat land thermal sailing i expect. I'll be posting some design renderings. Im using google sketchup so i will probably not have solid 3D bodies or if i do they will not be all nice and smooth but in reality i will sand then smooth.

[GreenAce92]

Well this is just a rough draft model i guess of what type of a glider i'll work towards. It has the 7degree dihedral wing tips for stability since the main wings are just flat across. This is a no rudder model, saving weight while still allowing aerobatics. yeah like i said it'll be something like this, my electronics(according to my drawings) seem to big for a 42in span model.well for the skinny small fuse anyways. When i see an F3J model in my head i think of like a Pike Perfect model, but after reading what F3J is i saw how the guidelines said, you launch and just pure thermal i guess is how i took it in as. Minus all the rules. But yeah so i'll see what i can do, need new foam, i have my DLG glider in the process of being built, having some troubles with the pod. Im going to try and do the whole horiz moving stab, i like the idea i think its great.

Or if it still counts as a F3J type bird,(launch, thermal) i'll probably build a mockup of a Schweizer glider.

[GreenAce92]

More progress, wing is finally in one piece, i tried the 60sec epoxy not so good... i just hot glued the joints. then im glassing it with 2oz/sq yard stuff. Will have to do top then tomorrow do bottom and overlap from towards the top so its a nice smooth finish. Yeah it is really sleek! i did a smooth light swing and it was so fast that i smashed it into a chair causing a dent im like dohh!!!! so i had to reglass that area, im not too sure about the pod, if anything i will carve out enough area to fit my electronics then leave the rest of the foam, i have to glass it more but i need more of the minwax stuff, stuff is great! then i have to build my Full moving horzontal stab, should not be much of a problem although im going to have it off center when its attached to the rudder, the rudder will be mounted hugging the side of the pod with some glassing. Still trying to figure out how to use Tow...

pics...
btw its roughly a 50in span bird with extreme high dihedral, i didnt notice how hight it was but at least it will be very responsive to my rudder inputs.

[steelhead]

Good stuff!

Dean

[GreenAce92]

Im starting a new non dlg project, this sailplane was bad, too much dihedral when you would throw it, the glider would barrel roll and go inverted. not too good. Im going for a 2.5meter wingspan as i found out that catching boomers you need big planes to see them!

[wingsnapper]

What you describe is a common thing when attempting to DL a sailplane without a +tail. Put that thing up a highstart and let us know how it does.

[steelhead]

Your wing does look like it has too much polyhedral. At those angles, the angle of attack on the oncoming wind can cause a huge stall as the plane fishtails and the wing changes attack.

It's not the size of the wing that will help you catch thermals. No matter what wing size, you will still fly it to the edge of your vision. Big wings do help with vision at higher altitudes, but it is all relative.

With 1 meter HLGs, 300 feet is great, but I occasionally feel like I could have gone higher with a bigger span.

When I fly 2 meter, I get the same feeling at 600 to 1,000 feet.

As far as sailplanes go, my fav size is 100 inch span. 2 meters is pretty good all around, but something seems to work best at about 100 inches.

I've flown sailplanes all the way up to 15 footers and like the way the 100 inchers fly. 15 footers are still visable at 4,000 feet, but it's not really fun to fly that high.

Be carefull- to build bigger usually means more cost.

Hot glue is useful, but is not strong.

To use the tow, spread out the fibers and lay them down ont he foam wing before glassing.

Dean

[GreenAce92]

oh! before glassing! i see... yeah i have to get some more material before i go puts around, not to mention another receiver i may have to borrow the Ar500 from my radian lol not too happy about that one

[steelhead]

Thought you might like to see this video of big planes in thermals.

No really great thermals in the vid, since they put the plane too high for the video camera, but you do get to see in one scene the camera zoomed in really tight on the plane, and it backs off back to reality. My camera has 10X optical zoom :)

Most of the scenes with planes in them are all at altitudes lower than 900 feet

I think that year we maxed out at 3,900 feet while on the race course.

At the altitudes we fly, we need a Variometer to tell us if the plane is rising or sinking. You get to hear the variometer in one scene.

http://www.rcgroups.com/forums/showthread.php?t=530220

Thought you'd enjoy it-

Dean

[GreenAce92]

Cool! thanks its very inspirational!

i know of the variometer ive heard of it before, it changes in pitch i was looking at a build of one for a model sailplane it was odd but cool

[GreenAce92]

Alright well now that i have foam, its time for my teenage imaginary brain to kick in, im thinking of a insane quick launch, like those sailplanes launched on two PVC pipes, where they get chucked in the air, so the idea is pop up wings, it gets shot like a bat outa hell and then it slows down, and stops(momentum dying) toggle the ch5 switch and extra wings pop out, and i sail! Im thinking of something weird though, like cellophane wings, two sticks popping out with flimsy plastic wings....


ahhh never mind just thinking some random ideas here im building something though to sail with no engine just a pure sailplane

wait i've got it, im going to create a simple mixed aspect ratio winged V-tail sailplane, dubbed BumbleBee you'll see why as it is a fat bird! ill draw some hand sketches and scan it

[GreenAce92]

This is a different idea, probably for a DLG flying wing type of bird

has a mixed aspect ratio wing it will probably change fuse wise, as i will not be able to balance it like this without a massive battery. I was thinking of doing a rotary drive for the outer ailerons with 2 really long wires, but i was not sure how to well actually i have an idea but not sure how well it will work.

[target]

What you need sir, is plans of an established design!

IMO, you are wasting some of your time (depending on what your goals are, that is) designing your own planes that may, or may not, fly well.
I recommend building kits or scratch building others established designs before designing yor own.
Just my opinion.

Rock on.

Target

[GreenAce92]

I guess, i just like creating and watching my own bird fly my main problem is getting the design into reality, as i cant really print out plans unless some does tiling or something for me

[Shedofdread]

GA92,

Take a look a at www.aerodesign.de under 'modelle' there are lots of 3-views of F3B/F/J etc. If you take one of the older designs, ie ones that had wings made of straight tapered sections rather than curved ones, you could 'interpret' ;) that design. That way you know it will fly well. No need to print plans - the dimensions tell you how big to make the foam panels and the templates you need can be printed on 'deskjet' etc.

Yes you need a fuz but with the dimensions, create your own. Fishing rod section for the tailboom and lost foam for the plug.

Bish, bosh, jobs a good 'un!

S

[GreenAce92]

well i've made several DLG sailplanes and other sailplanes already, i was just suggested to make this thread by a few people in order to not have so many posts...

i have built a version of what i made a rendering of up there of the muskrat

see below:
http://www.rcgroups.com/forums/showthread.php?t=1021306&highlight=Planker+DLG+series

this model was very successful! except when i tried to hi-start it, where she veered to the right and smashed into the ground, but it had discus launch heights of unfiberglassed gliders, i thought if i made it where most of it had a high aspect ratio, and blended the rest in it would work much better. I was also thinking of building a model of a vulture lol lots of those here.

I saw a video of a way to steer aircraft, where they would raise or lower the wing tips of aircraft wings, it worked very well! as when you watch videos of birds flying they dip one wing to turn that way

[GreenAce92]

crud according to this low aspect ratio wings are not very good for soaring makes sense how im understanding it is that there is less area to catch the uplifts, span wise anyways.. hmm...

http://www.nurflugel.com/Nurflugel/n_o_d/weird_04.htm

I am probably going to build a high aspect ratio flying wing sailplane but its a planker type(this is what i call them) where there is no sweep, the leading edge will sweep but not the TE

doing more reading, so indeed a high aspect ratio is the way to go for sailplanes, the airflow is spread out more thus causing less wing tip vortices problems, making more lift

[FLY F3B]

So, Mr. Ace, how is your thermalling coming along. Still have a flyable Radian?

Mike

[GreenAce92]

Ahh yes i do sir lol, she is a beauty! love it very durable in fact i had this problem lol she got alittle far from me about a mile, crash landed on nose(was stalling badly) had it all recorded on camera, but plane is great no damage. Sweet stuff! handles wind well

im working on my own 100in model of an F3J kinda sailplane

actually it will probably be a semi-scale model of some sort of a DG extreme high aspect ratio sailplane R/E to keep it simple once i get more glass cloth and perhaps a good hot wire cutting rig ill try and do an F3J model seems simple enough to me extremely strong, light and aerodynamic tiny skinny fuselage and strong spars

[FLY F3B]

Great. Have you been practicing your thermalling? You know, power up, shut it off, and keep it up as long as you can..... Let us know of your successes here will ya? Pay attention to the air...which direction is the wind (if any) blowing...once you know that, if there is any minor change in direction, it is likely due to a mass of warm air lifting off the ground and sucking the surrounding air toward it to fill in underneath where it was. Fly in that direction watching your glider carefully for signs that it is rising or changing course on its own and make adjustments to find that rising air mass...

Good luck.

Mike

Ahh yes i do sir lol, she is a beauty! love it very durable in fact i had this problem lol she got alittle far from me about a mile, crash landed on nose(was stalling badly) had it all recorded on camera, but plane is great no damage. Sweet stuff! handles wind well

im working on my own 100in model of an F3J kinda sailplane

actually it will probably be a semi-scale model of some sort of a DG extreme high aspect ratio sailplane R/E to keep it simple once i get more glass cloth and perhaps a good hot wire cutting rig ill try and do an F3J model seems simple enough to me extremely strong, light and aerodynamic tiny skinny fuselage and strong spars

[Kiesling]

In addition to practicing the things Mike suggests, you may also want to get in touch with these guys:

http://www.wnysef.org/

They are not too far from you and it can be a great help to see what other people are doing in person . . .

Tom

[12ten]

GreenAce I highly recommend this book to you. It will definitely accelerate your learning curve IRT aircraft design.

http://ecx.images-amazon.com/images/I/51WE6MF59GL._BO2,204,203,200_PIsitb-sticker-arrow-click,TopRight,35,-76_AA240_SH20_OU01_.jpg



get it here (http://www.amazon.com/Model-Aircraft-Aerodynamics-Martin-Simons/dp/1854861905/ref=sr_1_3?ie=UTF8&s=books&qid=1240272055&sr=1-3)

[GreenAce92]

i dont know lol sometimes for model aircraft you could care less about aerodynamics(not sailplanes lol) but i mean a flying sock? lol

yeah i have been thermalling i was out flying like i think max was like 3 hours with occasional engine but there were strong strong thermals! i could do a tight bank with wings perpindicular to the ground and i'd still rise! Mostly though the thermals are downwind so im squinting for a tiny tiny plane! thats why i'd like to get into a 100in span sailplane size, but im worried like the radian has a reliable way of getting back, often when i thermal im at least 1000ft away from my standing pt across not up i could only be 300ft up but its like 1000ft away from me

so a pure glider worries me on how to get it back, with 10mph winds or less its not that bad especially when you have height

[target]

Hence, the challenge.

Try a couple of clicks of down trim, and no motor on the Radian. The faster you glide, the more ground you can usually cover, but the sooner in time that you get close to the ground....
You have little to loose by trying that with the Radian; if you get in trouble, you can power up and climb.
But make sure you have a clear view between you and the ground the plane is flying over!

G/L,
Target

[blackoutjon]

well Mr. Ace when i fly my pure glider i always play it safe and when i sense i am getting to low and know i can't catch anything i always bring it back and point the nose down a bit and it doesnt really matter how fast i am going because i have spoilers so i dont worry about slowing dowm i just flip the switch and it falls like a rock (one reason to put spoilers in a glider), sometimes you get lucky though and just saturday i caught a thermal just 50ft off the ground ( at least i thought it was 50ft). it was pretty weak and didn't gain much altitude, but it did keep the plane up for an additional 3 mins. and even after that it was still low and pretty far down wind and it i got it back home safe and sound. My advice thought is dont even worry about it and you will do find just play it safe.

[blackoutjon]

well Mr. Ace when i fly my pure glider i always play it safe and when i sense i am getting to low and know i can't catch anything i always bring it back and point the nose down a bit and it doesnt really matter how fast i am going because i have spoilers so i dont worry about slowing down i just flip the switch and it falls like a rock (one reason to put spoilers in a glider), sometimes you get lucky though and just saturday i caught a thermal just 50ft off the ground ( at least i thought it was 50ft). it was pretty weak and didn't gain much altitude, but it did keep the plane up for an additional 3 mins. and even after that it was still low and pretty far down wind and it i got it back home safe and sound. My advice thought is dont even worry about it and you will do fine just play it safe.

[blackoutjon]

oops

[GreenAce92]

thanks for the encouragement guys! and the great advice and tips

question if i somehow figured out how to drive these 2 rotary drive ailerons on my sailplane,(later i could just do a simple 2 servo version which could be flapperons) but as i was saying, taking one servo and running 2 really long shafts which would have the bent ends which would raise and lower the ailerons like who it is done on the Super gee or light hawk i believe for the flapperons how pheasable is that? i dont think very as the wings would bend in flight thus causing binding on the spinning shafts?

[12ten]

i dont know lol sometimes for model aircraft you could care less about aerodynamics(not sailplanes lol) but i mean a flying sock? lol


Parlez-vous anglais?

[target]

thanks for the encouragement guys! and the great advice and tips

question if i somehow figured out how to drive these 2 rotary drive ailerons on my sailplane,(later i could just do a simple 2 servo version which could be flapperons) but as i was saying, taking one servo and running 2 really long shafts which would have the bent ends which would raise and lower the ailerons like who it is done on the Super gee or light hawk i believe for the flapperons how pheasable is that? i dont think very as the wings would bend in flight thus causing binding on the spinning shafts?


You are better off mounting smaller servos in the wings. Then you will be able to change the camber/reflex of the trailing edge, if you have or get a Tx that supports that.
The drag is minimal.

Target

[GreenAce92]

oh yeah my eclipse 7 can do that, needs alot of repair took a tumble down the stairs breaking many buttons, aside from that the pitch and roll trim do not work lol plus my rx's ch2 doesnt work haha so im using ch3 plug for elevator plus i can use the ch3 stick to trim it works good for now

[GreenAce92]

Well i am building tomorrow, dont know what exactly(another freehand but i feel like this one will be good) it will be a hi-start launched, i dont trust any of my friends yet to handle the radian no way....

Anyways keypoints:
- Large wingspan, high aspect wings
-all foam fuselage
-fiberglass reinforcements(finally hit 70degrees!)
-will probably be a R/E model only to keep it light

[GreenAce92]

Note to all interested-

I am sorry if there seems to be a gap in productivity ever since i have received the radian, although i do have this bird which can climb right up to the heavens, i still do have a desire to build and experiment and learn. but the main issue is that i have exams for school so productivity has ceased, when i can i go fly the radian, thankfully it is a fully capable bird but when i get time i shall resume.

Again this is only for those who were wondering why there isnt anything built yet but you know school sucks at the end of the year lots and lots of exams

[target]

School should be your primary focus; you're on the right track.

Target

[GreenAce92]

Alright come summer though i will be building like crazy, i do have many things i have to address though for instance

Fixing my Hitec Eclipse 7 buying another good radio for sailplanes got any good suggestions? i like the 2.4ghz but i like the functions And i guess im going to be going into pure sailplanes no power

[blackoutjon]

dude if you want a pure sailplane you should buy and Oly IIs and a high start, from what i have heard it is easy to build and fly, it also has a good airfoil for penetrating well. just thought i would let u know. I am even considering getting one this summer after i finish my 3m gnome. :)

[GreenAce92]

OH i have a nice hi-start already, im going to build my own bird gotta get a new radio though, for now ill do a simple 3ch aileron/rudder/elevator sailplane gotta steal my Parkzone Radian's radio not too happy bout that...