The king cobra comes with the core cut and formed to size. I only needed your hot glue sheeting technique but after watching your full build I would not hesitate to make a core from scratch. Thank you guys so much. As for adding "chapters" personally i would not waste your time and effort. Anyone who is interested in this should want to watch the entire video anyway. It's obvious its not your first day on the job 😉. Again thank you guys sooooo much for taking the time to walk us through this build.👍 Seriously guys I've built a fare share of balsa builds but some of the tips you presented in this video you cannot find in any book!👍👍 No joke! You Sir are a legend. Those 2 boys are lucky!
Thank you so much for the kind words .😊 Matthew & I built the king cobra some years ago powered it with a nova Rossi R13 60 rear exhaust with a tuned pipe she was quick unfortunately his servo lead was stuck under his wing causing a short and the rest is history lol a lesson learned
Thank you for another great informational video. I’ve been building my own models for over 30 years and have not built any foam core wings, very interesting. The thing I most enjoy about your channel is the fact that you are doing formative activities with your sons, this is so important in America, especially today. Keep putting out more great build and flying content, it is truly enjoyable. PS, more four stroke builds, they will do everything the two strokes will on sport aircraft when tuned and propped correctly. Thanks again.
Well thank you. It’s true most of the youth today lack some common skills, I wanted my boys to know how to do carpentry, have a well rounded understanding of I/C engines, electronics, fabrication with metal, wood, and most importantly have fun doing it and the best way I could think of was building and flying model airplanes and they love it and we learn something new on every build. What more could a father ask for thank you again kind sir
thanks for sharing ... i learnt a lot of new stuff particularly sheeting and heating the landing gear wire to get good consistent bends. nothing like experience!
Thanks again for yet another great and informative video. Outstanding. I've also built quite a few models in my day but have usually been hesitant to use a foam core construction. Sheeting the whole core usually leaves a couple places where the sheeting lifts a bit after time. Not sheeting the whole wing and using the cap strips looks like the way to go. I've got to get a chamfer plane, too. Never heard of such a thing. What a handy little device. I really appreciate the fact that you folks are sending along different tips and tricks for those of us that build our planes. Thanks again.
Thanks for the nice comments very much appreciated makes it worth while for me to do them. Side note if you are using a large pour space white foam the cap strip method may not be sufficient strength. I generally use cap strip method on green, pink or blue foam it is very close cell or very dense much stronger slightly heavier although if you’re not sheeting the entire wing the difference is negligible and you will have a stronger wing. Thanks again
That was pretty amazing to watch! You are a great teacher! I hope to see a lot more instructional vids from you in the future they really help us new guys! Thank you!
One last thing I've done in the past is to remove the foam between the cap strips, then you can cover in transparent film if you desire, great video 🙂👍
Thanks for the comment Glen, love hearing from you. It was an immense amount of work on my father’s (above comment) behalf. He did a pretty solid job. And it was all his idea!
Nice video with several helpful hints. Well done. One thing, I noticed when you showed the servos for the wing, the mounting lug brass sleeves appeared to be reversed. I have seen many installed as I saw in the video by club members. I was advised years ago, the flange end of the sleeve should be on the bottom resting against wood Servo bearer. When the screw is tightened down to point the rubber begins to deflect, that is the proper amount. The rubber also acts a deterrent keeping the screws from backing out.
I shared this with a group I just joined . Lot of great ideas there . The hot glue shocked me , was so clean , simple , and fast . The chamfer plane was a new one on me awesome idea .You could maybe save your self a lot of work , if you took some #12 or 14 copper wire and bend it to size of your landing gear block and servo holes ( make three , one for main block , one for smaller block , one for servo ) . Made to fit in your soldering gun make it a bit deeper and use some scrap plywood to use as runners so won't burn the balsa , two steps in one cuts it and hardens it same time. Give it a try on some scrap first , may surprise you . Do you put any type of cover over the servos , seems like oil would get on them .
Thanks for the comments and ideas I think I will try the soldering gun idea. No servo covers were used they are clear of the wheel path and no exhaust slime manages to get there. We are preparing a video of the airplane it’s pretty amazing. Thanks again
We have two moonrakers one with an os 46ax the other with a 55ax this is balsa USA best kept secret this could very possibly be the fastest airplanes we own but don’t let that scare you because they are gentle and precise. When we get proper weather we will definitely do a video
We are all well, thanks for asking. we have done so much since our last video we are not sure where to pickup at, but hopefully we will figure it out and get some more videos going
Awesome, Thanks for your video. I am starting my first build ARF of a balsa model (Phoenix Corsair 0.52). Which video would be the best to learn to build (installing the servos, pushrods, mounting the engine, fitting fuel tank and tubes linkage to the glow engine, glueing the hinges, installing the gear, etc.). Thanks
I suggested making a set of wires for your soldering gun to cut servo holes . look up Red Leader foam spar cutter . Will give you the general idea .. Still think your is best video out there
Good job. I found this video most enjoyable to watch, not having a lot to do with foam core wings, and seeing the process of building one, i found it very interesting to watch. What are the benefits of foam core wings to a standed wing ?
Thanks for your replies to date. the next question concerns the foam used. You are using what looks like one of the Dow roofing foams. These are fairly dense.( & possibly heavier) However, our DIY stores in the UK do not stock it. I note that most videos on the subject use white polystyrene foam. This is less strong. They also sheet all over. Presumably to compensate for strength. I much prefer your sheeting- hence commenting on your vid- How do you feel about using white instead of blue. Would I be in trouble if building an Avanti F3a 60inch wing like you have?
I assume you are talking about the a avanti by Donald Grassi I actually have the plans for that it looks really nice. The blue green and pink foams are heavier than the white however they are considerably stronger and do not require fully sheeting the wing. I would not hesitate to build that wing out of foam very similar as to how I did it in the video the only difference would be double tapping the center section. If we are talking about the same plane that thing looks like a really good design.
So far I have only watched a part but will watch the rest when i have the material to hand. My major question concerns weight. I am about to build an Avanti F3A plane & this would save hours of building time. How does the weight of a wing compare to a standard built up balsa wing? It would save me buying lazer cut parts & hence costs as the fuselage is relatively easy to cut from a plan with a fretsaw. But getting wing ribs dead right on such a plane would be vital. This makes it so much easier.
This is a great question the foam core wil be slightly heavier. completely negligible when you see how well a foam core performs in the wind a definite more solid feel. On my templer plane I designed I use both build up and foam core and find myself using the foam core more frequently. Give it a try
The wood I used is just standard size balsa wood there are several places on the internet to purchase balsa wood we are fortunate our local hobby shop has it. I’m glad you enjoyed the video
If one had a bigger wingspan ( say circa 63 inch) it would be interesting to see how you dealt with longitudinal stiffners, Carbon tubes, or ply cross braces, to reinforce the joint.
I have built multiple bill Evans simitar airplanes with 64” span with no braces just sheeted center section and taped. I have in the past put spars and dihedral braces in them using my table saw and router but it is a little messy thanks for the comment
Qustion I have on the pelican . When I cut the four cores it will be same templates . Can I just set the outer template to the required wash out and get what I need with the main wing and tips lining up right. And can I remove a good part of the foam between cap strips to save weight without losing too much strength . gonna be electric power and just an easy flyer as haven't flown in 40 yrs .
I didn’t mention it but after the core has been cut I return it to the blanks so it lays flat then I cut the dihedral angle on my table saw. I have also done them on my stationary belt sander but you must be careful with this method you don’t want to get the root out of square. Great question thanks
Lot of updates here to the original method for skinning foam wings. I like the use of hot glue for the balsa surfacing rather than the smelly rubber glue we used to suffer, and also the capsticks instead of skinning the whole wing which used to lead to awkward trimming of the final panel to fit. As you indicated, clearing out the holes for the servo and undercarriage block is time consuming. I wonder whether a dremel would be easier. We sometimes used a small hot wire tool, and that seals the foam at the same time. People should be aware that the vast majority of the strength of the wing comes from the balsa, not the foam, so the sheeting should run over the thickest part of the wing. Don't be too mean with the leading edge sheet. I think I would have made it 2cm wider, but then perhaps your flying style is more genteel than mine so i need all the strength i can get. Finally, the scrimming tape and CA does sound like a good idea, much easier than epoxy. And far speedier. 😅
Thanks so much for your comment an update on the miss bikini airplane we ended up putting a ST G-34 in it and it is my son’s plane and he is not gentle with it at all in fact he beats on it rather nicely and she is holding up well, we need to put together a video of it. The other factor on this type of wing is the torsional strength of the covering it kind of works like spokes in a bicycle wheel if you will, thanks again and I wish you many happy landings
Just a question I noticed you didn't cut any lighting holes in the foam have you ever and is it beneficial with this design do you think ? Nice looking wing !!! Lots if tips here
This is a great video and I've learned some handy tricks and methods but I'm curious as to which model he was building. It's probably hidden in the comments or video somewhere but I haven't seen it? Does anyone know?
Hi guys, I see you have HS 311 servos. How satisfied are you with them? Are they reliable? Do they have a bad potentiometer? I use Hs422 thanks for the reply, Jan
We have found that the pot in the 311 will fail if you use 6v we use are regulator set at 5.4v and have not had one fail yet. The manufacturer claims they will handle 6v but they will fail in a very short time speaking from experience run 4.8 to 5.4 and they are great. Thanks
The one I use is cordless and the sanding head is the shape of a triangle allowing it to get in tight areas or focus its sanding on small areas, I do believe at some point in the video I show it but needless to say great question thanks much
I am at the 19:14 mark. It appears the wing is “backwards “. The end has an up arrow and an”R”. So, if this indeed is the right wing, the skin is at the wrong end. We shall see. Please understand, I think the system is great, I appreciate the lesson. I know, it is a symetrical wing, so in this case it does not matter.
L'apertura alare è di 45 pollici o 1143 mm e il profilo è simmetrico. Spero che sia quello che stai chiedendo. Non parlo molto bene l'italiano. grazie per il commento.
You didn't mention how you attach the templates to the foam or how to make sure you don't introduce washout or droop and so they don't move during the cutting process. If you add a stop to your templates trailing edge you wouldn't have to worry about running past where you want to go. I also put a notch in the leading edge ramp so I can rest my wire there while it's heating up. Then you simply lift the bow out of the notch to start your cut.
Those are really good ideas and your right I didn’t mention that I use calipers to level my templets I just mentioned to make sure that they are level with each other, and I did mention in the video that I use drywall screws to attach the template. When you are doing these videos often times it’s easy to overlook things that are obvious to me but may not be to others and that is why we have a comment section so good people like yourself and others can offer suggestions or ask questions and we greatly appreciate it so thank you so much
On that wing I would cut a slot in the foam for the dihedral brace in it’s shown spot on the plan add an additional 3” of sheeting to the center section on each panel add leading and trailing edge sheeting and cap strips on there normal centers glass the center section no spars needed and you will have a very strong wing you will also find that the four star 120 will handle the wind much better. Thanks for the question
Why not just make a mould, put aluminium on the sides, insert a central strut and mix in the A & B mix and let the foam fill the void. Out would pop a finished wing in seconds.
