Originally Posted by rcjim11

Ok, that's great!, but one more thing: which airfoil do you choose? I have the profili program, so I would print the appropriate chord and go from there.
Thank you
Jim

The foam spar is the spacer that sets airfoil thickness. Wingnutt has produced an awesome little spreadsheet to calculate the dimensions.

Originally Posted by pdiddyg40

I totally agree. How did you do the lights? Just regular strips on LEDs on the inside before closing it up? Hows she look at night? Great build, sir!

That is about the size of it. I put different colored strips on the front and rear sides of the spar. I also added a couple of white LEDs on the upper surface of the wingtips to differentiate the top from the bottom. These small Depron wings are designed to hang from my larger 8 foot blu-cor wing (same basic construction) and be dropped in flight. Here are some pix from SEFF last year.

Now you've gone and done it. . . . tsk, tsk. See ? Now you have to explain the multi-engine, tractor mounting technique used on that big wing.
Out with it ! How did you mount'em (more specifically - How did you tie into the structure) ?

Originally Posted by sawman

Now you've gone and done it. . . . tsk, tsk. See ? Now you have to explain the multi-engine, tractor mounting technique used on that big wing.
Out with it ! How did you mount'em (more specifically - How did you tie into the structure) ?

I thought I had already posted this ... Oh, well, I suppose one more time won't bore anybody to death.

I use medium weight fiberglass cloth and finishing resin and wrap it around a wooden dowel that has been wrapped with wax paper. Once the tube is dry, I remove it from the dowel and cut the ends to length with a chop saw. The internal structure of the nacelle is made from carbon strip and plywood formers. I mount the motor with the extensions soldered in place and slide the skeleton into the tube allowing enough space so that I will have a gap of about 1/16" between the nacelle and the back of the spinner. The skeleton and 'skin' portions of the nacelle are then glued together with medium CA.

Once the nacelle is constructed, I slide it into a slot that I have already cut into the leading edge of the wing and then I apply foam safe CA to hold it in place. The bond ends up being quite strong. I can hold the weight of the entire plane by one of the nacelles without any difficulty at all.

Maybe you did post this and I just missed it. I'm not able to browse the forum as much as I used to.
Anyhow, interesting that the nacelles are just glued to the wing. I expected something to distribute loads to the spar, but obviously that's not necessary. Thanks for explaining.

Originally Posted by atone1

Mine are symmetrical and thick enough to fit the lipo used plus at least 1/8" clearance. The thicker airfoils seam to be a little more floaty (Slower) and the sleek thinner ones are for faster speeds.
Here's the crazy way I do the ribs. Measure where the rib goes and cut a strip of foam that length plus your thickness needed. Cut two 1" pcs of foam strips long enough to get the thickness and length needed. Cut the LE 45° angle on the front and tape both ends together. This creates templet with side view of your wing section right where the rib goes. Draw center line down the rib piece. Hold the templet on the center line and trace the inside. Cut out one and use it to copy the other one needed. I keep it simple as possible. You can get your rib length and do what ever airfoil looks right to you. I loop tape the ribs together sand a slight reflex in the top of the rib pcs but I don't even know if it matters.
Maybe I do that so I think I know something about aerodynamics. My wings fly like their on rails so I'll keep doing it.

I glue the ribs and spars to the bottom wing panel before folding the top over to glue it. let them dry a couple of hrs. I leave the forward camber of the ribs unglued so that I get the shape I need. Then glue everything and fold the top panel over; tape the trailing edge and weight it down good. Pu gorilla glue is great for this as it expands into all the voids and sets up. Let it dry over night.
Works for me,
Al.

Thank you for the detailed guide, I need to add that to my reading list for when building commences!
Is that section used as a template very thin mock-up piece so that you can decide how big you need the full wing & gap with the battery and all installed? Oh and could you tell me way the chord is on that one please?
Thanks
Jim

What is the official name of this wing design? Not sure what to write in my log book. And I don't use bluecore foam.

Originally Posted by FeiJi

What is the official name of this wing design? Not sure what to write in my log book. And I don't use bluecore foam.

I think most people are just calling it the "Bluecor wing", even if we are using FFF or depron.

Originally Posted by FeiJi

What is the official name of this wing design? Not sure what to write in my log book. And I don't use bluecore foam.

This is the original Bluecor Flying wing design from Daydreamer and the thread was authored by Scottflight. This is a chevon style flying wing.

You don't use BC foam? BC foam is the cheapest way to build lots of these wings.
Al.

Originally Posted by atone1

This is the original Bluecor Flying wing design from Daydreamer and the thread was authored by Scottflight. This is a chevon style flying wing.

You don't use BC foam? BC foam is the cheapest way to build lots of these wings.
Al.

Ok, Bluecor Flying wing. I can't find it here (China) and I'm not sure what the foam board is I'm using, its kind of brittle and covered with paper or a plastic coating. I get it from places that make signs. Well, the paper covered foam is brittle, the plastic coated is a little bendier but is heavier.

Originally Posted by FeiJi

Ok, Bluecor Flying wing. I can't find it here (China) and I'm not sure what the foam board is I'm using, its kind of brittle and covered with paper or a plastic coating. I get it from places that make signs. Well, the paper covered foam is brittle, the plastic coated is a little bendier but is heavier.

The plastic coated stuff is what you want.

Originally Posted by KFC

The plastic coated stuff is what you want.

I actually haven't been able to buy the plastic coated foam but I find it where old adverts are being thrown out. Got lots of it in store now so will use it instead of the other. I find that flying in -10 to -20c also makes the foam that much more brittle and prone to cracking and my tape quits sticking and the hot glue separates more easily from the foam. I was flying yesterday and couldn't figure out why my elevons weren't working, turns out the servos were just sitting in their holes but weren't attached to the foam.

Originally Posted by scottflight

Fold the wing over so that you pre-crush the leading edge.

Next hot glue in the spar strip. Glue it about 25-33% from the leading edge all the way down. Close is good enough, really. I think I did 25% in my last one.

ok guys what is the point in the pre crush I dont really understand
This is where I am currently at

Originally Posted by on1wheel01

ok guys what is the point in the pre crush I dont really understand
This is where I am currently at

It looks like you have already progressed beyond that point to me. I think all he means is to pre-bend or form the curvature of the lead edge to make it easier to glue the spar and join the trail edge. If you form just the top panel you will have a flat bottom wing. If you form top and bottom equally you will have a symmetrical wing. Hope this helps, others in here can probably give you a more definitive answer.

Here's the way I do the LE on the wing panels.
I just cut the back of each panel on the leading edge 1/4" back for 1/4" Bluecor foam. Sand it smooth with a sanding block. You can cut or sand a little more if you want to get thinner LE for faster wing setups.
After the LE is like you want it, I line up the root section of the wing panels with the LE and loop tape the back of them to the bench. This keeps the panels from moving while your trying to run a long tape joint. Make a 7/8" mark in a couple of places on one side of a wing panel from the LE back. This is used to line up the packing tape. Pull a nice long piece of packing tape off the roll. Start at ether end and run the tape all the way down the LE lining up the tape edge with the 7/8" marks. Most of the time I hover the long piece of tape over the whole run and line it up as close as I can. Stick one end down and use a credit card to squeegee the air out as I go or you'll get air pockets and wrinkles all the way down.
That's how I do all my long tape runs as static electricity will suck the foam up to the tape as you try to place it down. Do both of the LE tape runs before gluing the spars in. Try to get the root end as close as you can when taping or you'll have to sand it later to get them to line up like you want. Too much dihedral in your wing will make it a pain to fly inverted, so check it before gluing the two wing sections together.
Fun stuff those long tape runs.
Al......