Thread Tools
Aug 02, 2018, 06:33 AM
treefinder
springer's Avatar
Follow the link in my blog post here: https://www.rcgroups.com/forums/show...foot-span-wing

You may find some ideas for your build. The wing is only 7' span, but very stiff, and could easily be scaled up.
Sign up now
to remove ads between posts
Aug 02, 2018, 01:01 PM
Jack
jackerbes's Avatar
If you want it to be in two pieces for transport and put together for flight look at the plans I used for the 96" wing here that used fiberglass tubes and rods for joiners and spars:

Big Blu 96 KFm9-Winged-Glider - https://www.rcgroups.com/forums/showthread.php?1470211

The KFm wings are a wonderful thing if you're building with flat sheets of foam...

Jack
Aug 05, 2018, 12:17 AM
"Crunchies Rule"
oldscooler's Avatar
Quote:
Originally Posted by springer
Follow the link in my blog post here: https://www.rcgroups.com/forums/show...foot-span-wing

You may find some ideas for your build. The wing is only 7' span, but very stiff, and could easily be scaled up.
Here is my 100" scratchbuilt Vol-Lent aerobatic sloper. Wing panels are white foam cores sheeted with 1/16 balsa. Panels fully loaded are 15oz each, loaded fuse is 19oz. I have a rectangle CF wing joiner with full length 1/2" balsa sub trailing edge. Panels are very stiff and the plane performs very well. Now the girder boom may throw you off in this post suffice to say is pretty indestructible as the reason I invested the time to see how it works. It passed with flying colors.

But here is my question regarding duplicating these 50" panels in foam board. The root is 10" with a 6.5" tip. I want to reduce the fully loaded single servo panels down to 10oz each. Does anybody think it's possible to make this target weight with foam board and strategic CF stiffening tubes? Thanks... E
Aug 05, 2018, 03:58 AM
Jack
jackerbes's Avatar
Here is a 96" span 792 sq. inch wing that weighed about 16 oz., it is a two piece wing joined with tubed and rods that also served as spars. The plane flew at this weight:

AUW: 1460 grams = 51.5 oz.
Wing Loadingt: 9.4 oz./sq. ft. or 28.5 grams/dm2

https://www.rcgroups.com/forums/showthread.php?1470211

The only sacrifice on using the Kline-Fogelman airfoil for a glider wing is that the wing is a little thicker and has more drag so the power off cross country speeds were a little lower than better glider airfoils.

But that did not matter to me, I just wanted a glider and don't fly any kinds of competitive events.

Jack
Aug 05, 2018, 12:06 PM
"Crunchies Rule"
oldscooler's Avatar
Jack, will that airfoil fly inverted and perform rolls? I would sure like to see a video
Aug 05, 2018, 12:23 PM
treefinder
springer's Avatar
The 7' wing is built up with 5 ribs per side, 2 " chord height as I recall.the whole plane weighed 26 oz. So 15oz weight per wing is possible for a 100" span I would think.
Aug 05, 2018, 12:42 PM
Jack
jackerbes's Avatar
Quote:
Originally Posted by oldscooler
Jack, will that airfoil fly inverted and perform rolls? I would sure like to see a video
Yes on inverted, a big half loop and then some up elevator to maintain level. No ailerons so no real rolls but slow tail flip almost rolls.

Look for the Big Blu videos here: https://www.youtube.com/user/JackErbes/videos

That wing was stressed pretty well and it survived it all. It would take on a big curve on a hard pull up but it is still in one piece and never failed on me. Lots of fun to fly, just sit on the tail gate of the truck and go into a trance... It averaged right around 175 to 200 FPM descent rate with it's nose into the wind and just enough down elevator to keep it moving into the breeze.

And it would thermal too but I never had a good flying venue for thermals here on the coast. The coastal breezes tended to prevail over thermals.

Jack
Aug 08, 2018, 06:34 PM
"Crunchies Rule"
oldscooler's Avatar
First test try at a 30" tapered panel. Going for 50" next. 10" root, 7" tip. Still lots to learn.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Dollar Tree Foam vs Elmers Foamboard Tripod333 Foamies (Scratchbuilt) 21 Jun 06, 2018 06:44 AM
Build Log Dollar Tree Foam Predator Drone j8kuo Foamies (Scratchbuilt) 3 Sep 28, 2012 06:50 AM
Discussion black vs white dollar tree foam unbroken23 Foamies (Scratchbuilt) 11 Jul 23, 2012 12:04 PM
Help! 3D Plane From Dollar Tree Foam? nightfox7 Foamies (Scratchbuilt) 14 Jun 23, 2012 07:36 AM
Discussion sanding dollar tree foam woohoo Foamies (Scratchbuilt) 7 Jun 20, 2012 11:54 PM