zeslave

hi to all of u , i want to build a model which i have plans for it (downloaded free plans) but the main problem that i cant find balsa wood anywhere localy , here in egypt i have went to 5 wood stores and the surprise is that they don't even know it [] , so my question is are there any substitutes for the balsa , the model i am willing to build 74" wingspan .


Thanks in advance

BMatthews

Successful models can be built of any lighter wood but the design has to change. For example way back in the 70's or so Bill Northrop designed and built a model called the Spruce Goose. It was a biplane built entirely from Sitka Spruce. But the methods used had much more in common with stick and tissue free flight models than with normal balsa construction. To make up for the heavier weight of the material he built it all from thin sticks. So yes you can build a successfull model from other woods but it means changing the plans completley. No solid sheeted areas other than perhaps some 1 mm plywood around the nose, And the wood will probably need to be custom cut to suit your needs. Structures will need to be built up like you see in some of the current 3D models using small section square strips of wood. Lightening holes in the ribs.

A fine tuned bandsaw will be needed to resaw the wood down to thickness. Check for wood that is light but strong as in the same sort of density as Sitka spruce. A lot of cedars are suitable but if it's resinous then it'll be heavier and harder to glue. A light dry wood in the 15 to 20 pounds per cubic foot range would be best.

vicman

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Is foam available? You can use basic profiles to guide your shape, get creative with hollowing and lightning holes then finish it with fiberglass. Another alternative to fiberglass is women's hoseiry. Take some used pantyhose and stretch them over the foam and squeege in some thinned epoxy two or three layers thick and you are good to go. The foam method may weigh a little more but can be overcome with power.

zeslave

dear Bruce ,

Thanks for repling , pls i have also another question , i have found another plan which has been built by someone and posted the steps for building so i found this very easy to follow but the main problem is still the availabillity of wood (hhhhhaaaah here i come to the main question ) can i make the same plane he made with the same size using other ways i heared people talking about like epoxy ?

can epoxy method be used with any plans and model regardless the wing span or the motor size and if so how a motor can be mounted on fiber glass ?

Thanks in advance

the-plumber

This may sound like a stupid question, but not to put too fine a point on it, can you build and _fly_ model aircraft in Egypt ?

What I know about Egypt wouldn't fill the thimble for a piss-ant, but I have read that in many Arab countries aeromodeling is a no-no.

What I do know is that the countries which have any degree of aeromodeling to speak of, most if not all have a national aeromodeling organization, and those various national aeromodeling organizations are members of CIAM, the aeromodeling part of FAI.

I didn't find any national aeromodeling organization listed for Egypt, but that of course doesn't mean there is not one.

In any event, perhaps the best thing for you to do is touch base with other aeromodelers in your locale to find out what they are using for building materials.

Of course, if you can't find any other aeromodelers in Egypt, that could be a reason you can't find balsa.

Probably doesn't help, but it's worth thinking about.

BMatthews

Good point Fred. It also raises the issue of where other modelers over there would be. If you can find them then you'll find answers to a lot of your questions.

Another easy, cheap and strong method is to make your models from a form of paper mache. Lightweight white styrofoam cores either hot wired or cut and sanded with newsprint paper bonded on using water based varnish as used for wood floors. The stuff you want looks white when you open the can. Thin it with about 1 part water to 4 parts varnish for more soaking in ability. Use two layers of paper painted on overall with extra layers for strength. For example the wing spar areas would have about 4 layers of staggered size to avoid any sharp ridges with a layer overall. Around the nose you'd use 4 layers as well with a plywood engine mount epoxied in prior to the paper going on.

I made a few control line combat models using this method and they were pleasently tough. Crashing would tear off the occasional tip corner but none of them ever suffered from a loose engine mount or broken spar area. Later I broke one for testing and it took a few serious full speed overhand swings to knock the engine mount area loose.

So you see, balsa is only one method of designing. Look around for light materials and adapt to suit your needs.

What about engines and radios? If you don't have those you aren't going to get far.

Deadeye

Welcome to RCU!

Coroplast mat be another alternative. Check out www.spadtothebone.com to see these original and easy to make planes. I build with coroplast, but I also use balsa in my building method (but lite ply wood could be substituted no problem). Here's a few of my coroplast creations. I have about $40 USA into the airframes. All of these planes (except the white one) are copies of the popular SIG Four-Star. The purple one is the replica, then I bashed the design into a biplane, and finally the twin. The twin flew for the first time a couple of weeks ago. Also, check out the SPAD Forum right here on RCU!

Schpankme

Bruce,

I've never heard of a biplane named the Spruce Goose. Wasn't that a nickname commonly given to the Hughes H-4 Hercules, an aircraft designed and built by the Hughes Aircraft Company. It is the largest flying boat, and has the largest wingspan of any aircraft ever built.

Due to wartime restrictions on the availability of metals, the H-4 was built almost entirely of laminated Birch, not spruce as its name might suggest. The aircraft was a marvel in its time. It was also referred to as the Flying Lumberyard by critics, who believed an aircraft of its size simply could not fly.

__________
Schpankme

BMatthews

Yes the Spruce Goose is more commonly used for the Hughes flying boat but the name was also used for the biplane. Bill Northrop also put out a later all balsa version of the same outline but using standard sheeting and D tube construction called the T'winger. I don't have the old Spruce Goose article, if there ever was one, but pics of the super big 60 powered stick model showed up in a 60's vintage MAN as well as sitting beside the T'winger in the RCM article. But as I said this all goes back to the late 60's and early 70's.

zeslave

thanks to all of you ,

dear vicman i am not that pro to understand those few words u said , they realy sound great but i need some more info by details

vicman

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If you like you may pm me with your specific questions and I will try to help you get airborne

the-plumber

If you're talking about making ribs and formers (among other structural components) from foam sandwiched in epoxy/glass, why not describe the process here ?

I betcha a bunch of folks never heard of composite structural components and might like to know how it's done.

CrazyHerb

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When I was stationed in the UK. I built an all-hardwood plane using several sticks of basswood from local hardware store. Two rails for the fuse, leading edge trailing edge, thin (about 1/8 in ply for only 8 ribs...to save weight).

Covered it whith cheapest film I could find....flew it with an old .40....and it was awesome...

Sounded like a drum flying with the large open bays between ribs...but had NO profile to it....just two sticks....would flat spin like nothing I've ever seen.....

Ribs were only 1 inch tall..

Fun.....use what you can get a hold of....and keep it simple....

Good Luck!
CrazyHerb

RC-Captain

Deadeye....[X(] nice freaking planes dude, ! are all of them scratch built ?

Just my 2 cents, In you obviously have access to the internet, so why cant you just order the balsa from a web site that sells it?

good luck with building , I suck at it , or better yet dont have the patience nor the time to build.

Flying Scotsman 70

First off there is a small group of Aero modellers in Egypt and they usually buy models from abroad.Also what you said about your knowledge of Egypt is totaly correct. You obviously didn't do Geography at school as Egypt is a part of AFRICA It is an African country not an Arab one .

Also what you said about modelling in Arab counties being a 'no-no' is incorrect my parents live in Dubai and i can tell you that Aeromodelling is massive over there as in most Arab countries. In fact The President of the UAE ordered the building of the flying site!

the only thing i agree with is finding out what other Egyptian Modellers use or where they get there Balsa from.

The only thing i can think of is to find is finding the closest shop and make the drive but stock up so you never have to go back or try order it of the internet

the-plumber

Ah. Thanks for the history and geography lessons. Now I understand why Egypt is so pro-Israeli . . .

I must also have missed finding all references to Egypt's large national aeromodeling body in CIAM and FAI.

I can provide you with any number of references posted by folks in _Arabic_ countries which describe how difficult it is (or was) to practice the fine black art of aeromodeling.

I also can't seem to find any national aeromodeling bodies for Iran, Iraq, Syria, Libya, Morocco, etc., etc., ETC. !

Flying Scotsman 70

sorry if i came off a bit strong i was just pointing out that not all Middle Eastern countries are paranoid and against model flying (as you would have to be to ban it). Also in many countries the model flying group usually isn't big enough to have National Aeromodelling bodies like for examlpe in Dubai it is Extremely popular but there is not National Body like in the UK and US.

It would be nice though if aeromodelling would spread to these places and became popular enough to be accepted and established in society.

jolllyroger

When you build a heavier material i susually stronger so you can reduce the size used to keep weight down. When I was 13 I used to build airplanes from 2 X 4's that i ripped down with dads hand saw. these were then used sparingly and covered with news paper that i sprayed with krylon. These were the toughest best flying planes I ever had.