![\"drakeplans\"](\"http:\/\/www.balsaworkbench.com\/wp-content\/uploads\/2014\/01\/drakeplans.jpg\")
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I have this plan on my workbench right now. \u00a0So far all I have done is cut out a stack of wing ribs. \u00a0Ken Willard really knew how to design a model airplane, and he particularly knew about seaplanes. \u00a0If I build the Drake II exactly as shown on the plans I’m sure it will be great. \u00a0But I have my little idiosyncrasies. \u00a0For one thing, I generally like ailerons. \u00a0There are some classic planes (Q-Tee, Whimpy, Kadet) that seem even more classic in their original configuration without them, but I’ve added ailerons to a lot of planes. \u00a0My Drake II is going to get ailerons. \u00a0When building the wing, I can assume that the aileron will be placed exactly where Ken put his trailing edge stick and will be the same size. \u00a0That means I need a quarter inch stick of balsa just in front of it, glued to the ribs, and the ribs need to be a quarter inch shorter at the aft end.<\/p>\n
Another one of my quirks involving wings is that I like a sheeted D-tube wing leading edge. \u00a0You’ll notice that the Drake wing has sheeting only in the center section. \u00a0The outboard panels have no sheeting at all. \u00a0There’s nothing wrong with this method per se, but such a structure is susceptible to twisting. \u00a0Even Monokote can twist this kind of wing if you don’t put it on correctly. \u00a0Look at this photo of a wing, harvested from the internet:<\/p>\n
<\/p>\n Wow, somebody did a nice job of building that. \u00a0Anyway, the leading edge section includes a complete tube with a leading edge stick, thin sheeting on the top and bottom, and shear webs bridging the gap between the upper and lower spars. \u00a0A tube such as this cannot be twisted. \u00a0If you were to build this wing exactly the same, minus one of these four pieces, the wing could be twisted. \u00a0Try it next time you build a wing. \u00a0Twist the wing at each step, and when you add the last part, suddenly it is perfectly rigid…. which is why I usually build wings this way. \u00a0Actually, in much the same way that some planes seem perfect without ailerons, sometimes you have to build wings with pretty sticks and no sheeting. \u00a0A lot of old timers would look funny with leading edge sheeting. \u00a0But my Drake II is going to be built with a D-tube structure as are most of my airplanes.<\/p>\n With a D-tube wing, my Drake II won’t really need a big 1\/2 x 1\/2 stick for the leading edge as shown on the plan. \u00a0A lot of strength will come from the top and bottom sheeting, so I will be using a 1\/4 stick instead. \u00a0These various factors cause significant changes to all of the wing rib dimensions. \u00a0My ribs were 1\/8″ smaller from top to bottom, 1\/4″ longer at the leading edge, and 1\/4″ shorter at the trailing edge, than what is shown on the plan.<\/p>\n Now look at those spars on the Drake II plan. \u00a0Over the years I have seen lots and lots of plans that call for balsa spars. \u00a0I personally do not like balsa spars. \u00a0They are certainly good enough for flight loads, and I have never seen them fail in flight. \u00a0But flying is by far the least of the hazards encountered by model aircraft. \u00a0Landing, getting in and out of cars, and particularly crashing, present a far greater threat to wing spars. \u00a0My first low wing plane had balsa wing spars. \u00a0The plane was the Semper Fi from RCM, and it was a dream to fly. \u00a0I was enjoying the thrill of a snappy aircraft and becoming accustomed to the flight habits of a low winger. \u00a0On my first day out with this plane I did a lot of maneuvers that were demanding enough to prove to me that balsa spars were strong enough to handle flight loads, and then it was time to land. \u00a0One wheel got caught in just a little bit of long grass, and the plane swung around and jammed a wingtip into the grass. \u00a0Next thing I knew there was nothing but shredded garbage on one side of the plane instead of a wing. \u00a0No more balsa spars for me. \u00a0Ever since then (1991) all spars are basswood or spruce. \u00a0The increase in strength is tremendous, but the weight difference is negligible. \u00a0My rule of thumb is that 10 to 20 size planes use 3\/16 spars, 40 to 60 size use 1\/4, and the bigger planes use 3\/8. \u00a0Tiny planes use 1\/8 to 3\/16, depending on the situation.<\/p>\n Another detail I will be changing on my Drake II is the wing tips, simply because of the D-tube. \u00a0I don’t feel like blending 1\/16 balsa sheeting into the curved wing tip, so I will build the panels to end at the last full rib, then add a sheetwood tip just like the pretty wing I showed above for the D-tube detail.<\/p>\n This may seem like a lot of stuff to change, but it really won’t make the plane fly much differently. \u00a0The ailerons will make the plane more maneuverable, but other than that, to the casual observer it should look pretty much the same as the original. \u00a0Now consider the fuselage design:<\/p>\n <\/p>\n Notice the way the front of the hull is built, with 3\/32 balsa sides and bottom. \u00a0Theoretically this should provide plenty of strength for good landings, but who makes those all the time? \u00a0Sooner or later every seaplane will smack the water hard. \u00a0With a 48″ wingspan and a .15 size engine, this plane has what it takes to put a big crack in a balsa hull, and possibly tear some pieces off. \u00a0I can only assume that the original model was intended to be covered with light glass cloth. \u00a0Normally one would expect to see a detail such as this noted on the plans, but maybe it was considered a covering detail and was noted in the original magazine article, which I do not have. \u00a0At any rate, it’s not there, and I have serious doubts about the strength of the hull as shown on the plan. \u00a0In my opinion it should have light glass cloth, or a better grade of wood on the bottom of the hull. \u00a0I’m planning to build mine with 1\/16 plywood on the bottom and a 3\/32 balsa doubler about an inch tall along the bottom of each fuselage side. \u00a0A lot of seaplanes have a glass\/resin\/paint finish on the hull to keep them watertight, but that adds a lot of weight. \u00a0I’m planning to seal mine with a couple of layers of Balsarite and finish with Monokote.<\/p>\n There are some other details I will probably change. \u00a0The wing will definitely be held with bolts rather than rubber bands, and the engine servo will be installed in the engine pod next to the fuel tank. \u00a0I’ll probably do something different with the rudder and elevator servo mounts as well. \u00a0When it’s all done, it will look like a Drake II, and it will fly like a Drake II, but it will by my personal airplane. \u00a0My way isn’t necessarily better than somebody else’s way. \u00a0It’s just the way I like to build.<\/p>\n","protected":false},"excerpt":{"rendered":" Even when you have a good set of plans, sometimes it seems like a good idea to change a few details. \u00a0Perhaps you have a favorite way of building or mounting wings, or maybe you like taildraggers so much you … Continue reading <\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n