Ribbed Foam Wing: 2019 Edition

[@DonTimmons-kh4dz]

Appreciate your educational skills, and passion for helping us along with your building techniques. Thanks

[@duncanmartin2626]

This is super cool. I can't wait to try it with a 3mm depron skin, and then the doculam - should make a super light, fairly sturdy wing.

[@ricknoah9184]

I so like this technique !! Wow ! I've been contemplating a hot-wire rig for a while now. This video pretty much seals the deal on that. I'm sure you are aware of the nightmare a decreasing chord swept wing can get- no matter how it's done. I anticipate that 'wiring' the sweep and reducing chord will take good timing and I'll probably need to practice it before I do production wings. I LOVE the way that a "box" style set-up assures alignment of all parts involved. Brilliant ! I 'was' going to skin a wing with 210g beehive carbon fiber, but now I'm not so sure. Like you are saying... it's tough in all aspects of stress. Now- I will likely skin it with construction paper of a weight that gets clean bends. Then a few layers of acrylic clear coat to seal the paper and increase lateral strength. Then design painting.. and done. My concern, all along, has been both wing compression and large unsupported areas that could vibrate and detach the surface layer of air. It's about a 1.1 meter wing that will have a 4s 64mm EDF. Data sheet says it can get 970g thrust on 4s. I'll see about that. Heck, I'd be happy with a 1:1 thrust to weight and it looks, now, that I'll get better than that. Again... I'm humbled here. Thank you so much for his video. It will be a game changer for me.

[@CarlLydickRC]

Awesome! I was also really happy with the technique the first time I tried it. One thing that can also make this process even faster is to build your box 2x as thick as you will need and then use the bow to slice it in half. Now you have two identical cores ready to cut both wing panels! Can't wait to see what you build with it!

[@charlesbovalis6591]

Very impressed with this video. Especially at the 14:26" where it shows torsional rigidity ... I will try your technique on a small control line plane and then the sky is the limit. And for finishing I will also try the watered-down carpenter glue and light packaging paper. There are so many variations one can try. Thank you for providing an excellent creative "spark".

[@lzappa9109]

Dear Joshua. Thank you so much! Your efforts are really appreciated.

[@Kiromos]

I have made ribbed foam wings by cutting out individual ribs.. this is so much better! Cheers!

[@FINNIUSORION]

I had an old duraplane given to me with no wing, i used dollar tree foam board and drew out a wing and built exactly like you would with balsa. The most expensive part was the styrofoam ca glue that i have anyway for my foam planes. But it works great. Reinforced with a 1/2 inch spruce dowel down the center and glued plastic from a 2 liter bottle where the rubber bands contact the wing.

[@jdouglasmorgan]

It's a great way to make light weight wings. Having made several this way I have found a few things that help. Keep the Gorilla glue thin, spread with a playing card like Sparky applies it. Also make your wing boxes thicker than you expect, this leaves more meat top and bottom and makes the structure less flimsy. Finally, hot wire as soon as the Gorilla glue is ready, the longer you let it cure the harder it gets, makes cutting it more difficult. And WR has it right, make the box deep enough to cut in two pieces for left and right panels. BTW, I prefer brown GG for skinning but that's just me.

[@JoshuaOrchard]

Thanks for the comment, John. As I'm sure you are aware, your building is the main inspiration for this video. Cannot wait to get off my balsa building kick and give some new techniques a try.

[@wattwaster5936]

Getting back to the wing cores, cut them into sections, so you can use the better foam types to put ribs between the sections. Since I am making models with wing spans in the 2 foot total length normally, my sections are 2 inches wide so I can take out any defects. More often than not, these $1 toy foam glider kits have wings that are warped slightly, or worse. One of my videos can do a better show-n-tell that hundreds of words, but in short, the better foam wing ribs stiffen the wing cores. Once the Gorilla brand urethane glues have set and began to cure, which a light water misting can speed up a bit, I can think about what I want to do about a spar, which is only needed if I plan to add RC gear. All sorts of options will work, but since I am currently focused on gliders for my grandkids, even 1/32 inch thick balsa is overkill. If I use the lightweight RC gear, that thin balsa is more than enough if I cut the wing from root to tip carefully in the COG location. The purpose of the gliders is to help find the best location for the COG sweet spot with the center of pressure in mind. Most of my later RC flyers of the same aircraft design are around 10 to 20 percent larger than the glider. I am on a Bugatti 100p kick at the moment.

[@wattwaster5936]

I probably should read all the comments first before offering some hints and tricks with ways to make the work go faster and easier. OK, I don't see any comments about cold rolling thin foam board, which would have helped align the foam sheet better when you went to attach it. It is a very simple process and easy to learn, but you need some foam rubber that is bigger than what you want to cold roll. You also need the roller, which can be a stiff, smooth tube, or rod that is not curved, or warped. I have used a couch cushion, a foam topped bed, and large pieces of foam rubber that were at least 2" thick since it is the foam that will press the foam board into the roller as you move it back and forth against it. Place the foam board on top of the foam rubber, press the roller against the foam board, starting with very light pressure and with each pass, increase the pressure as you feel the foam yield. Done well, the foam board will roll up as tight as you want with no creases. I have cold rolled all sorts of thin (generally under 8 mm thick) foam board, even the cheap, thin foam dinner plates and takeout boxes. As long as the foam board is flat, you can cold roll it. If you need to cut out the flat part of a dinner plate, or takeout box, don't throw out the trimmed parts since they make excellent glue spreaders. I normally get by with a pieces that is around 2 to 3 inches long and around 1/2" wide. I use a marker to highlight the half of the spreader that will be spreading the glue so I don't grab that part and get glue on my fingers.

[@Andy-df5fj]

How does the crash durability compare to solid white foam and tape construction?

[@JoshuaOrchard]

Been trying to think how to respond to this question for a few days now and I suppose the best response is, it depends on the crash! It's not a building style that lends itself to be forgiving in a crash but more toward something that is far more light with strategic structural design. It would likely be easier to repair as the foam pieces could be easily joined using aliphatic or gorilla glue and then be re-covered.

[@Andy-df5fj]

@@JoshuaOrchard Thanks for the well thought out response. I've been thinking about building something with this method but then remembered why I fell in love with foam wings. They take a beating. However, now with the 249 gram limit, I might want to try something lighter even if it means flying less carelessly.

[@DanielSponholz]

I need to try this! Thank you for sharing. Very inspirational.

[@demej00]

Nice technique for large indoor planes.

[@JoshuaOrchard]

Hey man, you should check out the Seamaster II I built on my channel. Some of the best snow flying I've ever done!

[@topbrent]

Nice method. For a inexpensive covering that also greatly adds to the structural rigidity of the sheeting, it would be interesting to see you do a test using newsprint (packing paper) and 50/50 water thinned TiteBond 2.

[@JoshuaOrchard]

I've seen this technique used before and frankly it has no appeal to me. The finish is so warped that to make a scale model would take way more work than it is worth. I'd rather use epoxy and glass to get the finish what I'd like with better strength and a much smoother finish.

[@AEROERGO]

Very useful tip, mostly for big planes, but... how are you supposed to build an elliptical wing with this technique ? - Greetings from Argentina! ;) -

[@anthonylong601]

That was really useful thank you. Did you have any special joints in the purple spar section ?

[@wattwaster5936]

The method you are using is a lot more work and effort than is needed and since the common objective is to have a stiff, strong, non-flexing wing, not the best way to go and tons more difficult to repair. Cut out a wing core as desired with your hotwire device out of the really cheap, and easy to find "pop-corn" foam board used to make picnic coolers and all sorts of cheap insulating, or protective spacers in boxes of things. You can also find it sold as home insulation board, which often comes in 4'x8' sheets for cheap. The other home insulation sheets are nearly twice the price. Once you have your wing cores ready to go, you will notice they are a bit flimsy and easy to twist, or damage. Using a wood that is less likely to warp if it gets wet, like redwood used for fencing, cut the wood to match the shape of your foam wing half, but slightly larger, which comes in handy when working with cheap foam that is tapered. I am currently making a series of videos about this in a smaller scale using the $1 foam glider toy kits sold by the Dollar Tree store since they are terrible gliders, but can be made tons better to look like any aircraft desired. Now start collecting large foam drink cups for skinning your work latter, since it is free for the taking, or you can buy a box full for less than $20 in Sam's Club and other like stores. Most of us will never need to buy another box of foam drinking cups in 15 years, or longer unless you make a lot of huge aircraft models. I tend to save the large cups I buy a drink in and even save the thin plastic ones for skinning my cheap foam, easy to damage fuselages. What a lot of us don't seem to notice is how great these two types of plastic products are when used in our hobby.

[@manoomunicnent1773]

I use 5mm foam board flooring underlay. It's bare so no need to be removing paper like foam board and it's cheaper.

[@JoshuaOrchard]

Awesome suggestion!

[@charlesbovalis6591]

Can you point me to where I can get the 5mm foam board underlay please ?

[@wattwaster5936]

@@charlesbovalis6591 Large lumber and hardware warehouse stores often have it, but the new stuff that replaces the Dow, or Corning fanfold foams is a very different foam to work with. It is very stiff and subject to crumbling from the experiments I have tried so far. The old Dow fanfold foam for floor underlayment was blue in color and the Corning was pink with a cartoon drawing of the Pink Panther on one side. Both are out of production as far as I can tell due to the gas used to make the foam was harmful to our atmosphere.

[@charlesbovalis6591]

@@wattwaster5936 Thank you for your time - very much appreciated answering back to me. After doing some online searching today, I found a company that I will try their product ( Polystyrene sheets ) and I have several thickness options to choose from - the company name is: "Evergreen Scale Models Inc" and I can't wait to try their product ... Thank you again. I have ordered the 1.5mm 2mm and 2.5mm sheets to try ... can't wait to get my hands on these ..

[@wattwaster5936]

@@charlesbovalis6591 Oh yeah, I remember Evergreen. I don't recall them making a foam board, but their styrene products are famous for plastic kit modeling and model railroad. Their assortments are nearly endless for plastic modeling and they have been in business for more than 50 years.

[@factdesignbr]

Even the balsa ones get a lil flimsy brother. No worries. No I build using foamboard, wood and fiberglass but covering is always a challenge lol

[@dradden1556]

Very cool 👍

[@mpikas]

How did you get the paper off the foam board? It seems like most people end upwith a warped piece of foam that wouldn't work for this.

[@JoshuaOrchard]

I just peel it right off. Unless you are using Elmer's foam or the like, there is very little adhesion of the paper to the foam. While the foam is quite wobbly the entire point is to make many pieces to give it better strength. See my Seamaster II video. That wing is STRONG.

[@williamlukesr.738]

did you buy or make hotwire cutter whereto buy or how to make it PeteMaker

[@JoshuaOrchard]

AS with most of my specialty tools, I made my rig myself. There are many different setups out there that you can try. As, I worked with the publisher of this article, I'd highly recommend you give this link a read. www.flitetest.com/articles/hotwire-bow-parts-list-and-build-instructions

[@charlesklein7232]

is your method stronger then sold foam? certainly lighter!

[@JoshuaOrchard]

Strength is a relative term. A hot wire cut foam core has no strength to sustain an airplane until you add a carbon spar, fiberglass, etc. This example, I suspect is indeed much stronger than foam. The glue joints provide the load from lift to be distributed across the skin of the wing and into the ribs as well. Solid foam would likely be less rigid for lift but also torsionally. A simple foam core would have all sorts of twisting moments that would distort as changes in lift would happen unevenly across any more compound (non-square) wing shape.

[@manfredrichthofen3867]

This is a Part of The Wing! Give us a Wing!!!

[@JoshuaOrchard]

Happy to! kzbin.info/www/bejne/nqnPZ6OKr76NqKs It's all rinse and repeat to make wider. At a certain point you will probably want to have some sort of rigid spar but that Seamaster has been dead solid so far.

[@MarkHopewell]

Outstanding.

[@waiex1]

Shout out to Zamalot! And John Morgan!

[@poppopscarvinshop]

Very, Very Cool! Thank You!

[@excellenceinanimation960]

Brilliant!

[@fourfourfoureightyfour23]

: O MINDBLOWN !