I had been thinking of getting into R/C modelling for a long time, but it somehow felt like another expensive and time-consuming hobby which would be forgotten in a month, so I resisted the temptation. But recently the thoughts about it kept cropping up, primarily because of some things we were doing with the kids. We went to a local hobby shop, and asked about nearby R/C club. As it happened, there was going to be a big demonstration of models during that Labor Day weekend. Moreover, the store had a nice transmitter outfit at a very good price! Moreover, I just got a small raise, and my wife was also intrigued by the newly found toys. I had read on the Net that it's a good idea to start with a sailplane, since it's a relatively small investment and is fairly easy to fly. The only glider in the store was a SIG Riser 100 kit for about $30, so it ended up in the car's trunk alonside the radio. We spent the next two days at the modelers' show. It was just as exciting as the "real" airshow we went to some time earlier, despite some real show-stoppers at the latter -- a truck powered by three jet engines, and the B-2 bomber. The kids couldn't wait to get home and start building our glider. It turned into a long odyssey, since I was home only on weekends and couldn't spend _all_ the time making the model. Under normal circumstances it would probably take a week or 10 days of intensive gluing, sanding and covering to finish the model. Even though it was a bit more than we bargained for, I'm still happy that we didn't buy an ARF kit; we all learned quite a bit by having to do almost everything from scratch. I want to pass these experiences on to other beginners. * * * First, you need a good workbench. Since a complex model can take weeks to complete, and not every home has a workshop which is not used for anything else, that workbench should be easy to remove and prop against the garage wall or somewhere else. I worked on a trestle table I made a while ago. The top is a hollow-core door, which is recommended by most modellers as a bench surface: cheap, does not bend, relatively lightweight. The door can be placed anywhere: on a pair of horse saw brackets, or a trestle base made from 2-by-4s (like mine was), or on some smaller old table. If the surface won't be used for anything else, and doesn't have to be pretty, get the door from a lumber surplus yard -- you'll save a lot by buying one that is chipped or scratched a bit. Most of the time parts of the model need to be pinned down to the plans before gluing. The door itself is too hard for that, so it is important to put some softer material over it. If it isn't soft enough, you'll hurt your fingers trying to stick pins in it. If it's too soft, the pins won't hold the wood reliably, and you'll end up with a warped model and weak glue joints. Many people recommend fiberboard or chipboard which can be found at any hardware store. A more expensive board sold under the brand name "Homosote" is also good. Others use ceiling tiles, or a sheet of cork. The only important things about this element are: it has to be flat, it should be large enough to hold the largest pin-down structure you'll be making, and it has to grip the pins well. * * * I started out with only basic tools: - an X-acto pen knife and a lot of sharp blades - a utility knife with a sharp blade - some sewing pins - a long (3 ft. or more) metal straightedge for cutting longer pieces - a good, precise ruler - a pair of home-made sanding blocks, one with 100 grit and the other with 150 sandpaper It quickly turned out that ordinary pins were a big pain to use. A trip to the hobby shop got us a pack of T-shaped modeller's pins. They come in various sizes, but I am getting by with only the medium ones so far. I also kept having trouble with longer crosscuts in thick wood, even in balsa (not to mention spruce or plywood). A small 4 in. razor saw blade and a holder was the next item on the shopping list. It is essential for precise cuts which the X-acto knife cannot handle. On several occasions I could use small but relatively strong clamps, such as those sold in office supply stores to hold large reams of paper together, but I managed without them while making this particular model. Remember to use ones that aren't _too_ strong, and to put electrician's tape around the tips, since balsa is really soft and easily gets squashed under moderate pressure. I also had to use a small carpenter's square a few times. I'm fortunate to have a well-equipped workshop for wood projects, so I had drill bits, screwdrivers, a good small finishing sander and a precise variable speed drill. For the occasional rough sanding of a wingtip, or drilling a few holes in the fuselage, "big" tools can be used, if set to their lowest speed and operated _very_ carefully. But it's a better idea to spend another $70 or so for a good mini-tool kit such as Dremel. I'll most likely buy one before making the next model. For finishing I found the 150 sandpaper to be sufficient, especially if applied gently, without much pressure. Since my model will be covered with foil, its shin doesn't have to be smooth as silk -- simply "very smooth" will do, I hope. * * * Glues come in a bewildering variety. I decided to stick to [sic!] three basic types: thin cyanoacrylate (CA), Testor's wood model cement, and 5-minute epoxy. Cyanoacrylate, known as "Crazy Glue", is amazing. However, it's also quite expensive, especially in the form sold by hobby shops or mail order modellers' supply outfits. A 2 oz. bottle of it will run you $6 or more. There are several types: thin (which penetrates tight-fitting joints and sets very fast -- in a couple of seconds!), thick -- which sets more slowly and has a gel-like consistency, and the thickest one, used primarily for gluing joints with gaps in them. Because I'm cheap, I decided to risk an alternative which worked out pretty well. A local K-Mart or Farm & Fleet will have a wide selection of glues. Among them you can certainly find CA glues which work with wood. Note that ordinary "Crazy Glue" won't; the magic word to look for on the bottle is cyanoacrylate _ester_. I picked one (QuickTite) which was about $2 for a 0.17 oz. bottle, and it works just fine. This may not be the right thing to do when you are building a competition aircraft or a meticulous scale model for an exhibition, but it's OK for "ordinary" planes. CA which covers the skin dries into a tough shell, with potential bad health effects. Also, many people are sensitive or even allergic to its fumes. As with all chemicals, make sure to work in a well-ventillated space, and avoid skin contact with the glues. I use Testor's wood cement to glue large non-critical surfaces such as top wing sheeting. The reason is that it's very cheap, doesn't set too fast (so the pieces can be positioned precisely without great hurry), and the joints in question won't be bearing much of a load. I try to use it relatively sparingly, because it's much heavier than CA, and I strengthen the joint with a few drops of CA in strategic places along the edges. For strength and filling imperfect joints, epoxy is a must. It is also messy. You want to prepare everything in advance, get someone's spare pair of hands to stand by, and mix it _very_ thoroughly before actually applying it. Use a clean piece of wood to apply it -- the stick you used for mixing may be mostly covered with one of the two ingredients, so you'll get a weak joint if you spread that around. The 5-minute epoxy works best for me. It gives enough time to apply the glue and position the parts precisely, but sets before your fingers become numb from holding the pieces together. * * * When I first pinned down thin spar strips and the wing's leading and trailing surfaces down, and happily dropped CA on all joints, I ended up with a great mess. The paper plans stuck to the wood in all those places! This taught me the hard way to use one more layer: wax paper, or transparent backing from plastic covering such as Monokote (you aren't likely to have any while making your very first model, though...), or finally plastic foil used for wrapping food. Several people have had bad experiences with the latter, which apparently can be dissolved by certain CA glues. But my CA and Glad Wrap foil worked just fine for me. One more original idea suggested by an Internet contributor was to get a can of "tent protection spray", used to make tents waterproof, and spray it onto the plans; reportedly nothing will stick to them after that! Make sure not to put pins too close to the joints; otherwise the glue will seep onto the plans through the holes made by the pins. On the other hand, I found that the epoxy I had did dissolve Glad Wrap, and made the bottom of the joint look like gooey mass of plastic. You should probably use aluminum foil under such a joint, and peel it off right after the glued parts can be lifted safely. * * * It really pays to spend quite a while perusing the plans without even touching the parts. I know, you are anxious to start, but patience is one of the greatest virtues in modelling. Make sure you have some idea of how the parts fit together, which ones have to be firmly attached to each other and which ones will be hinged, etc. You might then want to look at all the parts, trying to fit them to the plans. Which balsa sheet is 1/32 in. thick and which one is 3/64? Which 1/4x3/8 piece is spruce and which one is balsa? Which piece of plywood will be needed for scraps and shouldn't be thrown out even after its main piece has been used? (as a rule, you shouldn't throw anything out until the model is finished -- even then, you might need some scrap pieces for inevitable repairs!) A large model like my 2 m. sailplane is likely to come with 1:1 scale plans, and those can be hard to manage while working over them -- especially if you start working on several parts in parallel (for example, assembling the fuselage while the epoxy which joins the wings is hardening will let you save a lot of time!) See if the plans can be cut into smaller, easier to handle logical pieces. Also, make sure that the plans are flat. They usually come folded several times, and will buckle even on a flat surface, making it hard to pin the wood totally flat. Get an old but clean rag, spray some water on it, and then iron the whole thing until the paper is flat. * * * It sounds like a truism, but it is very important to be precise when cutting wood. Some minor errors won't matter; but others tend to accumulate, and even small inaccuracies can result in an unacceptable dihedral wing angle, or a warped tail fin. In the SIG Riser kit the wings are composed of four pieces, with three epoxy joints which must be at a specific angle. Careless construction, in my experience, is hard or even impossible to correct by sanding later on. I wasn't precise enough in positioning the end ribs at the specified angle, and ended up with an imperfect joint. I hope I'll get away with it, because the gaps weren't too big, but I could have saved myself hours of delicate and tedious sanding had I done it right to start with. * * * The kit has a few parts which have to be bent out of shape and then glued, such as top leading edge sheeting. When a piece like that is long, it is impossible to achieve a good contact just by holding it down with your hands, and even many pins might not be able to take the stress of bending a half-inch wide strip so it touches the curved ribs. As a result, I got several bad joints which had to be re-glued. But thin CA glue, or wood cement, doesn't adhere well to wood covered with cured cyanoacrylate... In a few places I had to use epoxy to get it right. The combined Net-wisdom later told me that I should have used a gap-filling thick CA, or sprinkled a bit of baking soda in the gaps and then dropped CA on it. Baking soda apparently reacts with CA in such a way that it quickly dries to a consistency of a stone, or at least concrete! It is very hard to sand, but in some cases it can save the day. But of course it is best to dry-fit the parts, and make sure that they will adhere without a problem before applying even the first drop of glue. * * * Be prepared to improvise a bit. For example, my radio came with a tiny receiver which would easily fit in a much smaller fuselage; but the servos it came with were standard size, and with the servo arms provided with them they would not fit in the glider side-by-side. The salesman at the hobby shop didn't have any small wheels in stock, but very kindly agreed to take off a pair from other servos and sell them to me. The servos and standard trays still wouldn't fit easily, so I had to make a custom mounting bracket. This took some very careful fitting, cutting, and quite a bit of patience. If I had to do it again, I'd probably get a pair of mini servos instead. The nose cone had to be shaped out of a rectangular balsa block, and I didn't have a good carving knife handy. It turns out that a few cuts with a razor blade and then some careful strokes with 60 grit paper on a sanding block quickly reduced the piece to a shape which could be easily finished with a fine sandpaper. The pushrods in the SIG kit do not use clevises to attach to the servo arms; they are supposed to be bent into a Z-shape and inserted in the arms. But the wire from which they are made was too thick to fit in the holes; I had to very carefully enlarge them until the wire went through, but at the same time didn't have much play. My radio has the servo reversing function, so I didn't have to worry about it; but pay attention to how the motions of the arm will affect the control surfaces! You don't want to end up with a plane which goes down when you _pull_ on the elevator stick... Make sure the servos and pushrods are low enough to give you clearance for things that tend to be installed last. In my case it was a close call: the dowels used to attach the wing with rubber bands go across the width of the fuselage, and are marked on the plans; but by the time I got around to fitting them, my servo mount was firmly in place... The dowel pins barely cleared the pushrod sleeves, even after I drilled the holes for them a tad higher than indicated on the plan. I later learned the hard way that it was a bad idea after all: a hard landing ripped a dowel off, along with a piece of plywood. Follow the plan closely when it comes to servo location. They contribute the most to where the center of gravity will be, and you cannot alter this by much other than by moving the battery, the other heavy item, or adding a balast weight, which in an ideal world should be avoided. My CG turned out to be within milimeters from where the plans show it should be, but it could have been otherwise: I remember with horror that I was playing with the mount's position quite a bit, moving it back and forth to see what strikes my fancy the most. Luckily, they ended up more or less where the designer intended. Even so, I needed a couple of thick bolts wrapped in rubber foam stuck in the nose to make the balance just right. * * * Time to cover the model. It is a complex process, but it was in general easier than I expected (I was worried about it quite a lot). Still, I made a lot of mistakes. First, I underestimated the amount of covering needed. It should have been obvious that a 6-foot roll won't suffice to cover the fuselage _and_ a 72x6in wing (on both sides!) Get at least two rolls for an average size plane. Second, learning to apply Monokote-type foil takes a bit of practice and quite a lot of wasted material. I bought a TopFlite tacking iron, with temperature adjustment knob labeled with cryptic "Hi", "Mid" and "Low" settings. The TopFlite covering, however, recommends a specific temperature setting... go figure. I had best luck with the knob just past the middle position. There is no way to explain how to tack the material down so it won't curl, warp or break later. You have to have _the touch_, and that comes after a bit of practice. Start slowly: cut the covering roughly to size, think about the pressure points, and bend it around the edges. I start with the trailing end of the wing, and just slide the iron lightly along the edge. It will lightly stick to the wood, so you can stretch it a little and tack it with a long steady stroke to the leading edge. Don't worry about small creases and warps: those can be ironed out. But if the thing doesn't "look right", pull the covering off, straighten it out and try again. After tacking on the edges you need to cut the foil to size. Just slide an X-Acto #2 blade along the wing (or fuselage) so about 1/8 - 1/4in is sticking out beyond the line along which you tacked it in. Finish the job by gluing that free strip to the wood. Keep thinking about the forces that the heat-shrinking and air lift will exert on the foil. For example, if your wing is covered with two pieces of foil, and you don't iron them down to a wing rib spar strip and to each other, you will end up with a big hole when you heat-shrink it. All seams have to be quite strong to prevent this from happening. Covering such as Monokote doesn't stick to CA-covered wood. Moreover, my iron lost some of its Teflon when I was sliding it over such tough spots. Avoid them like a plague when applying the plastic foil. Seams are comparatively easy to make; if you have a wood surface under the seam, the bottom layer will stick to it, and the top layer will stick to the bottom layer easily. A few runs of the iron along the edge, and you will barely see the joint. Let the plastic overlap by 1/4 of an inch or less and you'll be OK. The initial covering is nothing compared with the inevitable repairs you will have to make. But by that time you should get the hang of it. Remember that there are two steps where you can correct things: one is when you heat the plastic with the iron, push out bubbles of air, smooth the wrinkles, etc. The second, more effective but also more delicate, is when you use the heat gun (an ordinary hair-dryer usually won't do) to make the covering stretch and shrink. Be patient, and move the heat gun back and forth in steady strokes. With some types of foil even a heavy-duty 1500W heat gun which can make hardwood smoke will take a minute or more to make the plastic pliable, and then to shrink it. Blow the hot air at an angle when you see wrinkles. * * * The first thing that will happen is that you will crash. That's why I chose a glider -- it's slow, and a crash won't dig a foot-deep hole in the ground, as it might with a powered craft. I went to a city park which had a 20 degree slope, with nothing around but grass within 500 feet. The wind was 10-15 mph. I threw the sailplane against the wind a few times to check the trim, then I threw it a bit high -- it flew a few dozen meters and hit the ground badly. I just wasn't ready. Be humble. accept the fact that the laws of physics are working against you. You'll learn to overcome them in due course. * * * There is an enormous amount of knowledge and experience available on the Net (you have access to it if you are reading this!) But many advanced modellers will frown and have little patience if you ask questions which show that you haven't spent any time trying to think them through, or researched them through "conventional means". Public libraries sometimes have one or two good books on making models; they can save you the embarrasment of sending a really trivial question to millions of Internet users. Magazines are another good source from which you can learn the fundamentals of R/C flying, model building, and -- yes -- some of the jargon the R/C people like to use. To mention just two, Model Aircraft News and R/C Modeller were very helpful to me. They also have many ads for instructional materials (books, videos) not sold through regular chanels. But the most valuable resource is your local club and its members. They can answer questions, show you their tricks first-hand, teach you to fly your first model, let you participate in their events. You may be too shy to ask for help, fearing that you intrude; but in most cases they are doing it all for fun, and the fun includes showing off their hobby to others. Imagine yourself five years from now, after you've gone through 3 radios and 10 models: what will _you_ say to an outsider who is eager to learn? When you are really serious about modelling, you'll have to join AMA (the principal nationwide modellers association), or else you won't be allowed to participate in any organized activities. The membership is affordable, and provides additional insurance coverage and other perks which are well worth the $50 or so per year. [12/28/95] (to be continued...)