Corplast for Thermal?

[daisycutter]

Does anyone have plans for a easy-to-fly, easy-to-build from coroplast plane for thermal?

Thanks in advance :)

[fprintf]

I have tried making a thermal glider out of blue fan fold foam. I used two arrow shafts for a spar - cut one arrow shaft in half and then attached each of the peices to the ends of the whole shaft with my chosen dihedral angle. So I had a flat center section with two upturned tips.

All in all I found the blue foam not stiff enough for any kind of histart launch. It does ok when attached to my slow stick fuselage and really floats around quite nicely. In fact in that configuration is probably stiffer than I actually need. It tends to flutter when any kind of speed is introduced.

How about just making one by eye like I did? If you have a cheap, easy source of coroplast then there is nothing wrong with making mistakes except the wings might fold.

How did you plan to launch it? tow hook and winch/histart? Electric?

[scififlyer]

Coroplast is great for slope, lousy for thermal. But if that's all you have, keep it simple and less than 6 feet/1.7m wingspan.

[steve wenban]

this post is a tad late I guess but i have 2 corroflute ships that thermal very well 1 is 2.6 metre and the other is 2.0 mtr in the style of Zagi's . but I am into slope thermal so I get the best of both worlds :D

[steve wenban]

the 2.0 metre version is by and large my favorite its fast great roll rate hangs on in a thermal and has a flat stall unlike normal zagi death spins :p

[Solcat]

What plans did you use? How thick of coroplast is it?

[steve wenban]

Sorry no plans yet They are still in my head I just drew it straight on the corroflute I made a half pattern from sail cloth and just go from there I will take some dimensions tonight when I get home and post them for you the thickness of the sheet is 3.0 m/m
with a 5.0m/m Sparwith the flutes running vertical its 6O.0m/m
thick at the root section and 15.0m/m at the tip (thats the 2.0mtr version) the sweep angle of the leading edge is approx 70 degs
and 60degs on the trailing edge will have to post the chord dimension at the root and tip tomorrow. I really enjoy flying the 2.0 mtr over the 2.6 it has a far better flight envelope but the 2.6 kick its butt in a thermal and its is remarkably fast but roll rate is majestic but slow .

[steve wenban]

iI sat down last night and drew up a set of lines drawings for the 2.0mtr version of my wing Called the Windshear 80 and will post them as soon as I scan them in so stand by

[steve wenban]

here's the line drawings .any questions dont hesitate to ask

[BMatthews]

Steve, I don't see anything about the airfoil shape on there other than the flute direction. Can you post up something that shows the airfoil for this unique model of your's?


Back to generalities-

So much of the performance of a glider for thermal flying centers around the airfoil shape that I feel this would be the biggest part of the challenge. The basic fold and pull that works so well for the engine powered SPAD's won't cut it other than for general trainer type gliders. In the end the control over the airfoil shape may be the biggest factor in a decent glider from this material. I think it CAN be done but it will probably take a bit more work whether it's for a flying wing such as Steve's or a conventional planform.

[steve wenban]

The section will depend placment of the spar Ive found that you can change the section in the corro from flat bottom to fully symmetrical the choice is up to you I have had many doubt that if flies so well but I only fly slope/thermal as my slopes around home are all inland slopes and I dont get the great coastal lift
Cheers
steve

[steve wenban]

just to add a note the current 2.0 mtr has a semi symmetrical section and work extremely well Experiment with it . it does work and flies great I have now built this model a number of times with an improvement on each of them

[steve wenban]

1 more thing to add regarding wing sections .Yes I agree that preformance is greatly enhance by choice of the miraid of wing sections available and much research could be gone into to achieve the perfect or near as can be perfect thermal design . However sorta defeats the purpose when you know that a clark Y
section will thermal very nicely (Gently lady ,Easy Answer)
the aim was to keep it cheap keep it simple
otherwise we may as well just build F3F models dont you think?

[steve wenban]

cool bananas Ive made senior member

[T. Lyttle]

Good thinking, Steve, don't try for a silk purse etc. If it is to be just a blunderabout job for the thermal field, coroplast should be just fine. ~30 years ago, a company manufactured(!) a cardboard kit that was not universally accepted as "serious", but it sure was cheap. It used music wire for spars, just bent in the middle; worked as well as could be expected for the price, consider it for yours.

Also, I got my nephews to build some freeflight gliders from cardboard, using a very unscientific airfoil bent in such a way as to incorporate a spar of sorts (not that hard, probably easier with coroplast). The stuff is cheap enough, knock yourself out, should be fun!

[steve wenban]

One of the ohter guys that as mad as me is experimenting with
cardboard of cereal boxes for upper surface wing skins with packing tape to seal them He has had a great deal og success on the slope using 3.0mm corro lower skin spruce spar and cardboard upper skin Ive even built a 2.0 mtr beetle out of corro
hes a -photo

[Mchone, Jake]

Cool! I've thaught of that cardboard idea...but never got around to it. ;)
That looks like a Gadget, is it? Ive always loved the Gatdget's lines and smooth flight! Ive never had one, but I am waiting for Stocker to get finished with his new Dadget DLG disighn
(thred here: http://www.rcgroups.com/forums/showthread.php?s=&threadid=190731&highlight=gadget )

[steve wenban]

No not a gadget more like a bluto redesigned by a fellow in Hong Kong and renamed the beetle But it was small so I redesigned it again and brought it up to 2.0 metres

[Mchone, Jake]

Cool-enuf!
:D