Ribbed wing vs different types of laminated wings

stereodreieck86

Active member
Hello guys,

what's your opinion on Strength and Weight vs a traditionell laminating method (Glasfibre/Balsa) vs foam with brownkraftpaper vs a rib construction ?

Cheers
Nik
 

Merv

Site Moderator
Staff member
I have flown old school balsa planes and FT foam board planes. The foam board planes are by far much tougher than a balsa plane. The will survive what would have destroyed a balsa plane. If you are building something super efficient or super fast, balsa may have some advantages. For me, a common sport flyer, foam board is the way to go.
 

stereodreieck86

Active member
Yes, I like to follow my German incentive and build something super-efficient. I am also experienced enough (7years into the hobby) to NOT crash my plane.
The wingloading is going to be 43-48grams per squaredm.

I purchased a HotWireCutter (yesterday), gonna practice a little and use my gained experience for something like a Cessna 1,2Meter.

A HoWireCut wingcore (left and right) would cost me 60bucks plus shipping here in Germany, plus the additionell cost for vacuum pump, bags, tubes and so on (probably in 150bucks range or more) plus uncertainty if everything is gonna go well which is unlikely because I am a Noob when it comes to this building technique.

Getting a wing build would cost me 350-500bucks.

A ribbed wing would cost me 80-100bucks plus covering film.

You can see the model I like to build the wing for in this video.
 
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Merv

Site Moderator
Staff member
Looks like you are going to build a glider type plane. I have limited experience with gliders, the high performance ones that I have seen are all built from composite materials, fiber glass or carbon fiber. A high performance glider in the hands of an experienced pilot is very impressive to watch.
 

bracesport

Legendary member
although not finished I have a DLG thread based on flyboa's work that has low aspect wings made of FB - I use a homemade handheld wire cutter and laminate the wing halves with Gorilla glue - the latest wing has a 3x1 CF flat added to the lamination - there may be some ideas in there for you! :D
 

Jackson T

Elite member
I just finished my 4 metre wingspan balsa glider, and the wing weighs around 1050 grams or so. That includes about 250 grams worth of wing joiners, as it's a 3 piece wing. It has some carbon fibre tow on the centre 1.4m section, which was about 21 grams, so it was definitely worth the weight. The wing has 93 sq dm of wing area, and the whole plane has a wing loading of 20 grams per sq dm. I think the whole plane cost me around $200 Australian dollars (123 euros) in balsa, and the covering film was $15 dollars (9 euros) per 5m roll from Hobbyking. I'm not sure if it would handle a loop, but it is a 4m wing, so it has a huge moment arm which makes lots of torque on the centre section.
Good luck with your build!
 

Corbarrad

Active member
A well-made and covered balsa rib wing will probably be the lightest and most efficient but also the most fragile of the three.
You may well warp your wing while building it, storing it or leaving it out in the sun for too long while depending on your covering material it might be pierced by as little as dried up grass stalks while landing.
Somebody tell me again why I just ordered parts for one...?

A glass-laminated foam core wing will also be pretty slippery and efficient, but the core will make it heavier and you will need specialized equipment to cut the core. laminating can be smelly, messy and altogether unpleasant, too.
They're also pretty much imperviouss to most storage and transport accidents.
You can also balsa wrap a foam core but the wood in turn will need protection by either paint or covering film.

Foamboard wings are cheap and cheerful, light and sturdy. They might not be the most efficient, especially with voids and bumps created by the foldover techniques used by most FliteTest planes. Short of getting slammed in the car door, being stepped on or folded in half by g-forces their only enemy is moisture and maybe too much heat, which will soften the glue joints.

So you basically have to choose 2 out of these three: cheap, sturdy and efficient.

And yes, a solid crash will do any of the competitors in...
 

Chuppster

Well-known member
A well-made and covered balsa rib wing will probably be the lightest and most efficient but also the most fragile of the three.
You may well warp your wing while building it, storing it or leaving it out in the sun for too long while depending on your covering material it might be pierced by as little as dried up grass stalks while landing.
Somebody tell me again why I just ordered parts for one...?

A glass-laminated foam core wing will also be pretty slippery and efficient, but the core will make it heavier and you will need specialized equipment to cut the core. laminating can be smelly, messy and altogether unpleasant, too.
They're also pretty much imperviouss to most storage and transport accidents.
You can also balsa wrap a foam core but the wood in turn will need protection by either paint or covering film.

Foamboard wings are cheap and cheerful, light and sturdy. They might not be the most efficient, especially with voids and bumps created by the foldover techniques used by most FliteTest planes. Short of getting slammed in the car door, being stepped on or folded in half by g-forces their only enemy is moisture and maybe too much heat, which will soften the glue joints.

So you basically have to choose 2 out of these three: cheap, sturdy and efficient.

And yes, a solid crash will do any of the competitors in...

A good middle-ground is a NerdNic Speed Wing. It uses DTFB to make a quick and slippery profile that cuts through the air pretty nicely.
 

Piotrsko

Master member
The only reason to use complex expensive materials is where the cheaper stuff cant structurally cope with the expected loads. Thin really high speed long wings for example. Otoh, most of your expenses are for re-useable tooling which reduces future cost significantly.
 

willsonman

Builder Extraordinare
Mentor
The only reason to use complex expensive materials is where the cheaper stuff cant structurally cope with the expected loads. Thin really high speed long wings for example. Otoh, most of your expenses are for re-useable tooling which reduces future cost significantly.
mmmm, I disagree... but only a little. The way the FT does their "oragami" style is quite strong for the size, but exceptionally dirty aerodynamically. Getting flight characteristics that are more real will require better materials that can accommodate cleaner building. The Master series is a step in the right direction however, still has several aerodynamic drawbacks.
 

stereodreieck86

Active member
mmmm, I disagree... but only a little. The way the FT does their "oragami" style is quite strong for the size, but exceptionally dirty aerodynamically. Getting flight characteristics that are more real will require better materials that can accommodate cleaner building. The Master series is a step in the right direction however, still has several aerodynamic drawbacks.

Aerodynamically dirty is definitely not an option, I am not willing to ruin the Look or Performance of my German Classic Vintage E-Glider, and the simple fact that we don't even have DTFB is the nail in the coffin(keep in mind I am from Germany).

I have a second wing for the Carrera Favorit but it is in bad shape and definitely not the latest and greatest airfoil (Clark Y) that's why I would to build a new set of sets (with a newish airfoil like RG15, HQW or S7036) but seeing how difficult (I can simulate and design a ribbed Wing in WingHelper) and expensive, at least 120bucks for a ribbed wing and god knows how much for the "Vacuumwing".

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Piotrsko

Master member
Idunno, been in the hobby forever. Name the material and I have probably used it for something that flew. Worked at Hughes A/C Space & Comm and had access to the exotics scrap can. Afaik, there was not much advantage aerodynamically at model scale at model reynold numbers. The wind tunnel data I saw said everything was inconclusive whether or not the boundary layer was attached or turbulent, definitely never laminar. But it's been 40+ years since I needed to mess with wind tunnel data so there may be some refinement.

Having said that, I also believe that FT models don't really fly, they just beat the air into cooperation.

If you want to do all that precision stuff on very exotic expensive equipment, by all means go ahead, hope you realize whatever benefit you seek. I just don't see the need to fly that in my schoolyard.
 

bracesport

Legendary member
I am pretty happy with all the different FT style wings as they apply to differing needs on differing planes - my latest DLG wing uses the DTFB shaped with my hand held wire cutter that is then laminated and glued with Gorilla glue - this embodiment of a wing (@750mm each) has a 3x1mm CF flat spar and I have just removed the paper and skinned it with newsprint - it is 11x160mm in the chord so should be quite slippery - check out @flyboa’s foamboard DLG thread to see how his design perform! 😆
 

stereodreieck86

Active member
I am pretty happy with all the different FT style wings as they apply to differing needs on differing planes - my latest DLG wing uses the DTFB shaped with my hand held wire cutter that is then laminated and glued with Gorilla glue - this embodiment of a wing (@750mm each) has a 3x1mm CF flat spar and I have just removed the paper and skinned it with newsprint - it is 11x160mm in the chord so should be quite slippery - check out @flyboa’s foamboard DLG thread to see how his design perform! 😆

I know your thread already, its on my watch list and the threads from Nathan Knight are on my watch list as well. Looking forward to your first flight.

The wind tunnel data I saw said everything was inconclusive whether or not the boundary layer was attached or turbulent, definitely never laminar.
So, you don't believe that airfoils make a big difference ?!

You can easily simulate an oldish Clark Y vs oldish E205 vs something like Helmut Quabecks HQ(W) in XFoil or XFLR5.
On that note: Liftdistribution makes a big difference too.

But it's been 40+ years since I needed to mess with wind tunnel data so there may be some refinement.
Puh, how can you make any assumption if your knowledge is 40+ years old ?!
 

Piotrsko

Master member
No I didn't say airfoils don't make a difference, I said that the construction method is transparent to the flight characteristics. I prefer a Naca 8% 40% laminar, semi symmetrical, but a shoe profile works good also particularly if you have narrow feet. A clark Y and associated "improvements" is really only good at producing drag but they are easy to build for the novice.

truth is truth, no matter how old it is. Your Sims are merely educated and smoothed guesses presented in pictographs in color. What occurs when the computer says it will fly and it don't? And where did you get your data for the computer from?
 
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