Fokker D.VIII Ep.02: I'll be your wingman

[@jimslaughter4579]

I never would have thought to do a built up wing totally out of foam! Good stuff!

[@JoshuaOrchard]

Thanks, Jim! My latest project (the Saab B.17) is built in much of the same way only for a heavy metal warbird style. A lot of folks are SHOCKED when they find out that the spar at the outer ends is only foam but the strength is there. It's all totally floppy to start with but as you add foam pieces the strength increases with it. I appreciate your comment and following along.

[@johnkunz2018]

I am really digging this build. Thanks for sharing it.

[@typxxilps]

I just subscribed recently due to a recommendation from someone else and just want to let you know that I like your work and love for details. Thanks a lot of sharing even those tiny points that a gorilla glue loves to glue on its own once it had been opened. And of cause a FOKKER is always a plane I love to become airborn - greeting from Germany

[@JoshuaOrchard]

Thanks for following along! Bigger does fly better and more room for details!

[@stompar]

Another great video ! Answered some of my questions about wing structure and connecting Servos and electronics to foam

[@rodchurchill5576]

Really loving this build ! But I would have made the outer wing spar in one piece and cut the ribs . I may be wrong but seems stronger that way .

[@josephkerkau2520]

Cutting foam ( pink) use the bandsaw for your curves, and use the table saw for your straight edge..very Is smooth edge....

[@eyobabebe7536]

I really like ur job man keep going, but i want to ask u something about the foam, what type of foam.u used for the ribs (green one)? And can u make us full building of the p51 mustang and please share us the plan in the description!

[@GRW3]

I learned watching an Adam Savage video that most razor saws are Pull Saws. The cut when you pull and just compress the wood when you push. You still go back and forth but ease off on the push, you’re just relocating the saw. My cuts have been cleaner since then.

[@JoshuaOrchard]

Excellent point! I should touch on this the next time I use my razor saw.

[@samerset26]

Great content! You're an awesome builder. I'm more of an orthodox modeller - foam is reserved only for electric motors and I use balsa and ply for nitro or gas engines. But this project(mianly wing's weight) made me consider using shown techniques and materials for 1/3 scale Nieuport 11 powered with 38ccm 4 stroke gas engine. Of course additional wooden spars whould be necessary as well as plywood construction of firewall. Also the whole model would need to be covered in Oracal covering film to prevent foam from melting after contact with exhaust gasses/fuel. What's your take on this idea?

[@JoshuaOrchard]

I think you are on the exact right track. The foam work would likely need to be glassed with epoxy in general to protect it, sure, but more to make it more rigid from the vibrations of the engine and give torsional strength. I've seen many B-17 models with foam core wings that are sheeted in a balsa skin. This is a great idea for your application since the balsa can act as an additional fuel barrier and also give the added torsional strength. Do keep in mind that ANY foam that is simply covered up and not coated in an insulative balsa barrier will experience off-gassing of the foam from the heat of the sun, causing the bubbles on the surface. If you go this way, the model only sees direct sunlight when it flies.

[@samerset26]

@@JoshuaOrchard I appreciate and value your feedback! I didn't know about this foam off-gassing effect, thanks for info ;) When it comes to foam core wings covered with balsa sheeting, the weight difference between them and classic ribbed construction with balsa sheeting (3mm ply ribs with propper lightening holes) is negligible, at least from my experience, but airfoil difference along the wing is significant . Probably, just for s**ts and giggles, I'll try this method - foam ribbs and formers with pine spars (single spar made by two pine slats on top and bottom with foam sides creating a box spar) and stringers, all covered with 4mm foam and covering film. Plywood used only in criticall points and as firewall (without using fiberglass or carbon). Maybe lighter, faster to build/repair and cheaper (with todays prices and shortages of balsa) outcome will outweight fragility and transience [don't know the propper word to express that it will most likely survive max 20-40 hours of flight time] of this solution.(english is my third language) So i'll get back to work and finish current BKB-1 project, and when the time comes, I'll keep you informed about how this idea is working out.

[@allanknights136]

I noted in your wing ribs holes that I assume are for a carbon rod/tube? My question is, how do you calculate where the holes are cut, assuming there is some dihedral.

[@JoshuaOrchard]

Well, surprise! They are not for a tube spar! As you can see in the video I only talked about the ply spars. The holes are there for running your servo wire. This is fairly typical. Since I did not design this airplane I cannot speak to how it was determined to use a tube spar or not. Generally the stringer/shear web design can be very effective and light weight vs. the simplicity of a tube spar. If I were to design this I would use CAD and incorporate the tube and simply subtract the geometry of the tube from the ribs. Pretty much any CAD software should be able to easily do this.

[@JRIVERA1124]

Where is the plan for this , please

[@JoshuaOrchard]

The plans are from Aerodrome RC that I personally scanned and enlarged to 1/4 scale.

[@bobsteffens376]

what is the white foam board that you skin the wings with and where do you get it

[@JoshuaOrchard]

This is foam board from the dollar store! I peeled the paper off first and it makes an excellent skinning foam for this build. You can order it by the case and have it shipped to your door so you do not have to sort through the store trying to find non-damaged pieces.

[@JimmyC_2112]

Looking great. I've just started playing with hot wire cutting. Two things. A topflite woodpecker would be easier than the one hole at a time with a nail technique , I'd think. 2, the cutting out of each shear web according to plans. that sounds like a real pain. As well as so many places to get an accumulative issue by the time you get done. Well done. I would not attempt it. I'm curious if this "box" technique would be quicker or easier. I'm looking forward to seeing the rest of this build. kzbin.info/www/bejne/jWiYdo2ajseaeas

[@JoshuaOrchard]

Yes a woodpecker tool would also work, but easier? I don't know, They are smaller parts and the time taken is minimal at best. We're splitting hairs on that one. Cutting the shear webs is no more difficult than cutting them from scratch on balsa anyway. Any way that you join them together will be work regardless of your effort and foam is cheap. Why not just use the cheaper material if the time invested is the same? The box technique that Carl uses is the same that we've both learned about from our old friend John Morgan. It works however since I am not sheeting my model in balsa, I need thicker ribs to alleviate the "droop" that you get in the foam skin. Sure, I could use the thicker foam but that inherits more drag in the hot wore as you make your cut. Being limited to about 30" of width for any hot wire cut makes this a difficult endeavor so you end up doing things in sections, which then becomes more work to figure out how to join... Keep it simple.