Goldberg Gentle Lady
Below are some pictures of the first plane I made, a Goldberg Gentle Lady. These pictures were taken after I had been flying it a while (after many crashes and repairs). Overall it has been a great first plane. It is very stable, handles well and soars and soars and soars...
After building a couple other models (mostly hand launched gliders), and logging a number flights with my Gentle Lady, I discovered a few things I would modify if I were to make another one. I would make the fuselage a little stronger and change the way the wing attaches to the fuselage. The dowel that holds the wing on in back has broken off a lot, and is usually the reason why I have to stop flying after a crash. I would also change the control linkages from balsa and wire to nylon tube and wire. The balsa pushrods are somewhat large to fit in the space toward the back of the fuselage where the tails mount. For more details see the section below, Gentle Lady Modifications.
Gentle Lady Modifications
Figure 1 (above) shows the original suggested design that the plans and instructions that come with the plane outline. The rear hold-down dowel has broken off a number of times after hard landings. The modifications I would make that should help solve this problem are shown in Figure 2 (below). I would change the hold-down dowels such that they go though and stick out of the sides of the plane. Then to attach the wing place rubber bands from the front dowel on side to the back dowel on the other side. I have used this design on other planes and it seems to hold up quite a bit better. If you make this modification you will also want to add some reinforcement to the sides where the dowels stick through, and glue the dowels to the formers.
Now that you have made modifications to the hold-down dowels, you can change the fuselage structure a little. My Gentle Lady is the only plane I have put together that had the upper sheeting on the fuselage behind the wing run with its grain in the same direction as the fuselage length. All the other planes I have built run the sheeting cross grain. Running the sheeting cross grain adds quite a bit of strength without adding any weight. There are a couple of reasons I can think as to why the Gentle Lady does not run the sheeting cross grain, one, it makes construction a little easier, and two, it makes it possible to add an access hole to the rear hold-down dowel (if the sheeting was cross grain, it would probably chip/break of pretty easily by the access hole). But if you have modified the hold-down dowels you no longer need the access hole, so if you want to put a little extra time and balsa into making your gentle lady you can strengthen the fuselage without adding any extra weight by running the sheeting cross grain.
The final thing I would change is the control rods/linkages. This may be more of a personal preference, but it will also allow you to add strength to you model. I prefer to use the linkages that have the rod/wire run through a nylon tube. With these linkages, as you are building your model, you put the tube in and know exactly where your control wire will run, instead of guessing where push rods will end up. With the nylon/wire linkage you no longer need to worry about clearance through the back of the fuselage. This will allow you to make the rear former just behind the wing a solid square piece instead of a square piece with a big hole in the middle of it. This rear former has been the source of most of my problems with the plane. It really is not strong enough and is the first thing to break in a hard landing (as stated above the rear hold-down dowel beaks off). If you use nylon/wire linkages, you only need to put two small holes (one for each control linkage, Figure 2 only shows one, there would also be one running along the other side) in the former to allow the linkages to pass through.
I have not actually tried any of the above modifications, but I am planning to someday when I have the time build another Gentle Lady. If you try any of the above let me know how they turn out.
Ben Yahr's Redtail
I have plans for another two meter sailplane. It is called the Redtail. I got the plans from Ben Yahr. I am currently working on some other projects and do not know when I will get a chance to put this plane together. The plans are drawn with flaps, rudder and elevator. I will probably also add ailerons. Below are some pictures of Ben's models.
© 2001-2002, Matthew J Litke