Balsa, SPAD, and foam- comparison?
 

I've built a SPAD already because they're cheap and durable but am curious about other materials. The guys at the field say that balsa is lighter and more precise- looks true by the planes they have. But what about foam? The idea of cutting out a wing in one pass looks good.

Any thoughts on the advantages/disadvantages of the various materials?

RE: Balsa, SPAD, and foam- comparison?
 

hot wire foam cutting is done it is then often sheeted in thin balsa this si done alot in high speed models as jsut monokote would simply employd..

RE: Balsa, SPAD, and foam- comparison?
 

hi im going to start building a plane and im wondering what meterials i should use foam,balsa thats my chouces my dad said

RE: Balsa, SPAD, and foam- comparison?
 

On sheeted foam wings, it is the balsa skin that gives the wing its strength, the foam only gives the wing its shape. For even higher strength, the wing can be covered with glass cloth and epoxy or some other resin.

RE: Balsa, SPAD, and foam- comparison?
 

The decision on building materials should be made based on the plans and expected performance. If you're building a small electric, unsheeted foam can be a great, lightweight building material. If you're looking for more speed, additional strength might be needed, which might require balsa or fiberglass covering over a foam core. Balsa is a simple material to work with, but will require some work. Remember, all decisions are a tradeoff. Lighter building techniques often sacrifice strenghth (OK, not if we're talking carbon fiber).

I just finished a plane of my own design that is a foam core fuselage and foam core wing, with 1/16" balsa sheeting. 68" wing span, 54" fuselage length, final weight about 8 lbs. I could have built lighter, but its quite strong. I like the way it flys, but others might not. I may try building the same design next winter with a balsa stick frame.

Let us know more about your expectations for the final product, and then we can advise on materials.

Brad

RE: Balsa, SPAD, and foam- comparison?
 

Long ago, I read about someone using foam wings with grocery bag paper glued to the outside as a skin. Either wood glue or epoxy works well. This paper skin considerably adds to the strength and stiffness of the wing.
A few years ago, several of the guys at our flying club were flying a simple flying wing design powered by .40 engines for RC combat. The wing was hot wire cut foam covered with self sticking shelf paper for strength.

RE: Balsa, SPAD, and foam- comparison?
 

All I know is the SPAD materials- durable and heavy. I am playing around with the idea of making my next wing out of foam, but am curious if it saves weight and also how it compares to coroplast for strength.

RE: Balsa, SPAD, and foam- comparison?
 

Not quite accurate. Byron originals had many large scale designs that were foam with low-temp covering covered directly over the foam. Their strength came from the use of hardwood spars inside the wing. Most guys cover the foam with balsa to make it easier to cover, and to make it dent resistant; not strength.

RE: Balsa, SPAD, and foam- comparison?
 

Not quite accurate. My Cor-Star series of coroplast planes come out within a pound of their balsa sisters. Of course, the durability is a no brainer. 500+ flights on the airframe in the picture. Foam cannot cut it when it comes to durability with coroplast.

RE: Balsa, SPAD, and foam- comparison?
 

A lot depends on the type of flying you want to do (or are capable of doing).

Coroplast is great if you want to bash your planes around. I think if an all-out nuclear war broke out, only cockroaches and coroplast would survive.

As to foam, there are three types of foam planes, Flat foamies, molded foam fliers, and balsa-covered foam, which is usually reserved for wings only.

Now, that said, Foam wings are heavier than built-up balsa wings, but more resistant to damage.

If your skills are at the point where you are wanting to try a nicer plane than you can build with Coroplast, I would HIGHLY recommend getting a kit. When you build with wood, there are a LOT of things to consider in the design. With a kit, all of the engineering has already been done (Like where to put doublers, and how to strengthen critical areas, etc.)

If you tell us the type of flying you like to do, we can recommend several, well-proven kits.

RE: Balsa, SPAD, and foam- comparison?
 

I'm so new it's hard to say at this point what my goals are. I'm really just trying to build skill now. I'm flying a SPAD Debonair which is a bit heavy according to the guy whose training me. The logical next step is to go to a flat wing with maybe a thinner profile for more speed and maneuverability, hence the question about foam or balsa building. I'd like to do combat later on and maybe build an aerobat too.

RE: Balsa, SPAD, and foam- comparison?
 

Try a Sig Something Extra. It's a very easy build, it's easy to fly on low rates, and it's very versitile for learning several different types of flying.

http://www2.towerhobbies.com/cgi-bin...1p?&I=SIGA6176

RE: Balsa, SPAD, and foam- comparison?
 

Blue foam covered in brown paper is worth a try. Lighter stronger much cheaper than balsa and much easier to repair. I build wings this way up to 45" with .32 engines.

There is a kit for a 4 engine Lancaster of 8 foot span that blue foam and paper. Flies eally well on 4 x .15 Sc engines.

We fly 12th scale combat and I have wings that are 3 seasons old and still good.