For this project my aim is to build a glider which can carry a digital camera for aerial photography but above all it should be backpackable so that I can take it with me on hikes or on my bike.
I have started my build from scratch today. The design is based on a uav I saw on discovery. The wing is elliptical with a 2 meter span and max chord of 12 inch. The fuse is 50mm pvc tube. CF tubes for wing and tail boom are all 8mmx6mmx1000mm. The wing tips are glued together with plastic tube. Two 6mmx25mm CF rods are used as joiner for the wings. The wings are held together by tension in the bow string which also gives it a smooth polyhedral like profile. Finally there will be a piece of fabric stretched between the elliptical frame to form the wing.
I am planning to keep it under 1500 grams and powering it with Turnigy AerodriveXp SK 35-30 1100Kv motor swinging a 11x5 prop.

Wow!!! Innovative stuff after a long time!
All the best! keep us posted. 

Nice approach.. can't wait to see the finished product..

Thanks ujjwaana & medicineman1987, lets see how it turns out.

Glad to see such a thread here

Teaser. Do you plan to keep a 'Flat Profile' planform of the wing aerofoil ? if so, the wing loading would be very high as such planform would not provide good lift.

Thanks anwar!
@ujjwaana
It will have a triangular airfoil, more on it here. You'll get a better picture as the build progresses 

Right now i am stuck because i am not able to find good string for the bow. In the pictures above i have used a metal wire but i have to replace it with a string. I bought three deferent types of strings, one was not strong enough and the other two just stretched out due to the tension from the CF bow 

ok i get it, great  , was looking forward to this. all the best for the maiden

Good one... tuned in to this thread.

All the best for the build and maiden

BTW, I have made a design of foldable delta wing sometime back. It should be back-packble as well. Will post some details later on.

-Ismail

All the best for your built.
Very Innovative....   

Great to see this thread.   Watch out for that weak area in your last photo. 

Great Innovative  build , this should be a great FPV platform

Quote from: SunLikeStar on December 26, 2010, 10:15:58 PM
Right now i am stuck because i am not able to find good string for the bow.

Did you try Kevlar String for Tennis Rackets?
http://cgi.ebay.com/GSs-Dura-Match-19-Kevlar-Aramid-tennis-string-1-set-/130395008092?pt=LH_DefaultDomain_15&hash=item1e5c25ec5c

You may well get these in good sports stores, for a little more price. The best feature of Kevlar is that they do not stretch.

Any local supply of kevlar in sports shops? Don;t think it makes sense to buy a new racquet and stripping off the strings ;-)

Thanks for the inspiring comments guys!
@izmile would love to see your foldable delta design, if possible please post some details here.
@ujjwaana Good idea!! i'll check local sports store for kevlar string today itself. Thanks for the pointer.

Good to see something innovative. All the best for the project.
How about using the pull pull wire for the tension? Will it work? Even the catgut used on badminton racquets should be pretty stretch proof and strong enough. If you need more strength you could use the tennis one. These should be availble at shops which restring the racquets you do not need to buy a new racquet and destring it.

Ujwanna
With respect to your post at #5,
Whether one chooses a  flat plate or any other aerofoil, wing loading will not change based on the aerofoil chosen   

Great Stuff Amit..Would like to see it, try to get it at pancard if possible..

All the best.

Quote from: SunLikeStar on December 27, 2010, 03:51:42 PM
@izmile would love to see your foldable delta design, if possible please post some details here.

Will post it later on. I have not made the plans yet. Further, I don't want to bias your design.

Got hold of some tennis racquet gutting, not kevlar but still doing the job pretty well.
Attached is a picture of my plastic tube joint for wing tip. Can you guys suggest a better way of dong this

By design itself this carbon bow type frame may not be a great idea. Preferably, instead of tension'ing the carbon tunes so much at the tips you could bend them lesser and have balsa or foam blocks at the wing tips. The CF tube ends could be housed inside these blocks (at a lesser angle and the blocks themselves could be shaped to the ellipse you want.

In any case don't you first need build the wing frame with ribs and spars and then attach the LE and TE tubes??

Thanks for the help tg.
Inserting another smaller diameter plastic tube in the outer tube has solved the problem for now. If this doesn't work i might go the balsa block way.

Quote from: tg on December 29, 2010, 10:19:59 AM
In any case don't you first need build the wing frame with ribs and spars and then attach the LE and TE tubes??

The LE TE tubes and a string is all there is to wings, no spars or ribs whatsoever 

Wow! I was assuming this to be a regular built up wing. Forget what I said in earlier comment. I've got a similar (40 inch wing span) glider made of rip-stop nylon and CF rod but much smaller than yours. It flies best in almost nil wind conditions and is free flight. And like yours the wing dihedral is formed by strings that pull the wing halves upwards and connect to a pod attached to a CF fuse.

What do you plan to cover the wings with.

I am planning to use that silver car cover fabric commonly found nowadays, however initial tests will be with newspaper covered with packing tape. Can you post a few pics of your free flight glider.

Sure, will post tomorrow.