Okay, i want to get into scratch building just because it seems fun and i can say the plane is truely mine when its done. the question i have is when building the wing, do i use THIN PLYWOOD for the ribs, or THICK BALSA?? Obviously the balsa will be lighter, but the plywood will be stronger. i have never built a plane before and havent looked too closely at kits. does anyone have an answer?</p>

Typically, the ribs will be balsa, usually 3/32-5/32 thick. The plans should specify. If you want to design the plane yourself, you may want to look at several plans first to see common ways to do things.

What is the best way to cut them out. I was at the hobby store yesterday and i saw many cutting tools. there are small hobby saws and also saw blades that fit into an x-acto knife. or would it be best just to use a plain old hobby knife?</p>

Scratch built models are almost always done from plans. The designer specifies on the plans what thickness to use for each part. Thinner balsa can be cut out with an Xacto. Plywood can be cut out with a hand saw, but is much better cut out with a scroll saw or band saw. Thick balsa requires the same.

You should ask around to see if any flying buddies have kept copies of old model magazines. They used to have construction articles every issue. The designer often walks you through the whole process and usually includes tips and special techniques. They always included a picture of the plans so you could study the design. You could learn a tremendous amount just reading some of those. If nothing else, you'll understand how simple or difficult they can be.

I strongly recommend building a kit first if you,ve never built before. There are SO many things involved that you are not aware of. Building a kit will teach you volumes of things you hadn't thought of

Agreed.

Scratch building requires so many skills it's almost too much to ask here. This may sound a bit harsh, and trust me that Idon't mean to be harsh, but if you have to ask the question then you're not ready to scratch build planes. As Minnflyer says, start by building kits as you will learn the skills needed from the kit. Most good kits will have instruction manuals well laid out and they will show you how to do many steps. Once you move up to building from plans then you have those skills and you know what to do, when to do it, or when not to do it.

And as a quick answer to your question.Ribs do not need the strength of light ply. Ribs are not a structural component of the wing that gives the wing it's strength. Ribs are to set the shape of the airfoil.The strength of a wing comes from the spar structures in a wing.

Ken

G'day

Like the others I'd suggest you build a kit first. Something like a Sig Kadet Seniorita or Kadet Senior (larger version of the same plane). These kits come as a box full of sticks and sheets plus some wing ribs. The plan and instructions will tell you how to build it and you will learn a lot about the structure of a typical older style model and what wood to use where.

To build it you need some sharp knives, a razor saw, a very flat surface that you can put pins into, some T pins, glues of various sorts (epoxy, aliphatic resin, CA medium and thin), and some patience. A razor plane is handy too and you also need some flat sanding blocks with some 80 grade and some with 200 grade paper glued to them.

Generally ribs are made of balsa, spars from hard balsa and/or spruce and the fuse can be made from light ply or balsa or an open frame like the Kadets I mentioned.

And then there is covering but that it a completely new story.

I have just built two Kadet Senior models and am now building a small oldtimer called a Tomboy designed by Englishman Vic Smeed in about 1950. It needs an engine of between 1/2 cc and 1.5 cc capacity and is probably a bit smaller than you are thinking. It would be a good subject too if you have a suitable engine. The original was intended for free flight but mine will have some very small RC gear in it so it won't fly away with my 0.5cc MPJet diesel.

The Kadet Senior needs a 40 two stroke or 50 four stroke and the Seniorita will fly with a 25 two stroke or 30 four stroke though I used to fly mine with a 15 (2.5cc) diesel.

Have fun.

Mike in Oz

Yes, build a kit first that is what I did. My second plane was built from plans. As for tools, that second plane was built with an xacto knive, different grits of sand paper, hard rubber sanding block, and a coping saw. I built my next three models with just those tools, I have since bought some power tools too make life a little easier. You just don't need to buy all kinds of tools to build models when first starting to build from plans or designing your own plane. Good Luck and have fun, and yea you get more attention when you show up with a plane that knowone else has and is not an arf.

I agree with the others, start with a kit or two first. You will learn a lot about how airplanes are put together, the building process and so-on. Then when you are ready to attempt a scratch-build, start with something relatively simple.

My first build from plans was the Fun-Fly Hots. I bought the plans from Model Airplane News. Since it was a profile, the fuselage was just built from sticks and there were so few wing ribs, I just cut them out with an X-Acto knife and sanded them to get the final shape just right.The other main tool used was a razor saw. Basically, you can build that particular airplane using the same tools you have on hand from a kit. As you get into more advanced builds that require more cutting, you will need more tools. Another good one is the original Ugly Stik. It has a simple box fuselage and simple wing design. Plus it flys great.

Building from plans or designing your own airplanes is a whole other side to the hobby. I just wish I had more time to pursue it myself.
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Every now and then the topic comes along about Plans-Scratch and Kit building. The purest will state a scratch build is when the builder designs his own plane and then builds from there own plans, OK, very true. I used to use the term Scratch/Plans when speaking of my own builds just to keep the purists happy. They are correct but I gave up saying it that way. As I kid I designed my own planes but today I just buy my plans and call it scratch building, sort of like baking a cake, I didn't grow the wheat or lay the eggs to bake from scratch.
If you haven't built a few, not just one but a few kits you may find even building from plans a bit daunting. If you buy plans from MAN or RCM they will come with the original building article from the magazine, sometimes these will even be of help. Most of my own planes have been built from plans. I buy my wood in bulk from Lone Star Balsa. My main tools are my scroll saw and belt sander. A good moto tool is always a help.
You may want to try building from a kit so you have a better idea of what the different parts are called and what types of glues and clamps you may need in a build.
If you really want to build from plans then look at the Model Airplane News Plans Service and buy a set for an easy build. The plans are numbered, a number 2 would be easy and a number 4 would be hard. They have a good selection of plans, so does RC Modeler. Plans will show the sizes and type of wood needed for all parts.

Make your choice quickly though. Kits are going the way of the dodo bird. There isn't much of a good selection any longer, and there will be less in the near future as well.

Brian

Gray Beard, MAN no longer sends out the constrution artical with ther plans. Last plane I built from there plans there was a spot on the plans that refer you back to the construction artical that I did not have. I call MAN and was told they quit sending the construction artical about 5 years ago, but you can buy the back issue if it is avalable. I don't buy from MAN anymore.

We have several "old timers" in our club. They are all SAM (Society of Antique Models) members. All of the planes they fly are scratch built. These guys are artists, without a doubt.

CGr.

RCM still provides the construction article with any plans that are purchased there.

www.rcmplans.com

Ken

I second this suggestion. Build a kit of a plane in the scale you would like to scratch. It will give you a lot of experience with building materials, methods of building light yet strong in the right places, and you will still have the satisfaction of having built and covered it yourself.

I was told that but two years ago I bought a set of plans from them and the article came with them. I figured some came with them and some didn't. Most the time they don't help a lot anyway.

I agree with all said so far, build you a Sig kit to get the hang of it. Then pick out a plane you want to build from plans. Ultimate is to have a scroll saw, sander and band saw but you can build most with an exacto, small hobby hand saws and sandpaper. If you really get into it you collect more and more tools to make life easier. Also comes in handy when it comes time to repair the old ARF. Plans, copies of plans before building, templates, rib cutting techniques, sanding, covering.... I think I'll pull out a kit and start building. It's cold outside! Let's see, will it be the Ercoupe, or Waco or Something Extra or Hog Bipe or Supersportster or and hey by the way you'll also start collecting kits when you can find them. Here, Ebay, craigslist! Good luck, it's fun. I found my Pica Waco and Jack Stafford Ercoupe right here just talking with guys that hadn't even advertised them for sale yet. So they are out there, you just have to look for them.

Jim

[/quote]do kits come with some of the tools you need to complete them? or are you just saying if you bought the tools for one kit, you can use them for another build.....

do kits come with some of the tools you need to complete them? or are you just saying if you bought the tools for one kit, you can use them for another build.....
[/quote]
Kits don't come with tools. That is part of the reason for going that way. You will acquire much of what you need in tools, ans see what more you need during the kit building. A scroll saw was mentioned, and you will want a small belt or disk sander, and even a small drill press comes in handy. Many things are needed / useful to scratch build.

If you want to build from plans/scratch you will need some basic tools plus the scroll saw and sander. A kit will have MOST the parts cut for you so you don't require the scroll saw or sander. All other tools are still going to be the same. The main tools for kit building is a razor knife and sand paper. If you do a search you will find a number of threads buy people asking about the tools needed for there shop with pages and pages of guys mentioning different things they use. As a kid I started out with a tube of glue, wax paper, a flat piece of pine board, some straight pins and a razor blade. You don't need a lot of tools to build a kit and some kits tell you on the first page of the instructions what you will need.
If you go onto towers site you can find a kit and they often have the instructions posted so you can down load them. Give it a try. Print them out then sit down and read the instruction book so you have an idea what you are in store for during a build before you buy a kit. No reason to spend money on something you may not be able to finish. It can also give you an idea what it takes to build different types of planes. A trainer kit is a lot easier to build then a warbird.

I just received plans for the "Double Eagle 40" from RCM plans this week. I already have a back issue with the article, but the set of plans did not come with a printed copy of the article. I purchased a few plans from the old RCM magazine 3-4 years back and all came with aleast a text copy of the original article (no photos).

Jim

RCflyyer,

I have copied this quote from one of your other threads:

As advised above, building from a plan is not adequate to your building experience.

Unfortunately, you are starting off in the era of electric power, ARF’s and RTF’s; hence, finding a kit of your taste is somehow difficult.

Besides that decision, another important starting decision is the power source.
After that, you will need to invest in the hardware that supports that type of power.

This article will give you dimensions of a practical size trainer plus a good combination of electrical elements:

http://masportaviator.com/2010/05/14...pha-450-sport/

This kit is comparable in dimensions and could be converted to electric power:

http://www3.towerhobbies.com/cgi-bin...?&I=LXJ555&P=0

These ones are a little smaller, are tail draggers and maybe are less stable than a traditional trainer, but they combine kit construction and electric power:

http://www.stevensaero.com/StevensAe...0-p-16492.html

http://www.stevensaero.com/StevensAe...0-p-19120.html

These articles will show you the main steps in the kit building process and electric power usage:

http://www.rcuniverse.com/magazine/a...rticle_id=1196

http://www.rcuniverse.com/magazine/a...?article_id=67

http://masportaviator.com/2010/02/09...iner-part-one/

http://masportaviator.com/2010/02/26...lage-and-tail/

http://masportaviator.com/2010/08/04...er-part-three/

http://masportaviator.com/2005/09/07...ctrical-power/

http://www.stevensaero.com/Selecting...1.0-nid-5.html