I believe the name for this plane would have to be, "Flite Test Swappable Bloody Sullivan Armin Wonder". It is getting a little long and my son keeps telling me I should not name all my planes bloody sullivans just because I always bleed on them at some point, (Hint #1, be careful of your xacto blades).
My son has built two of the Bloody Wonders from the Flite Test plans and I just wanted to play with making one with more of an Armin Wing style. I really don't think it will have any superior flight characteristics, I just thought it would be fun. I measured the original Bloody Wonder to come up with the design and the cutout. The one major change is the tail section is the same piece as the center of the wing, to do this I cut it as shown and added a 4 inch strip to each side to get the wing to the correct length. You can see the cut out below with lengths shown.
The 4 inch strips should be added before you cut it out. That will ensure glue all the way from end to end for a stronger bond. The strip is added by using a strip of clear packing tape half the width under the body and half the width under the strip. Then hot glue down the gap. Just be sure you let it dry on a flat surface and be sure to run a scrap of foamboard over the glue while hot to force it down in and create a perfectly flat surface.
Once I had it cut out, I taped the opposite side.
As you can see, I like a clear difference between top and bottom on my planes. The black and purple change is right where the top section will fold back to create the upper section of airfoil. I flipped it back over and removed a half inch strip of paper right where I want it to fold.
In the Armin Wing build he just removes the paper from the entire upper section. I like to remove this strip first. Fold the top section back at this point. I find it folds back right where I want it every time without having to use a straight edge to force it. After you have the first fold done, now remove the rest of the paper from the upper section of wing. (I forgot to do this at first and ended up creating a crease in my upper section instead of a perfectly smooth curve).
Now add your internal supports. Cut a strip 1 inch wide and a second 1 1/2 inches wide. Glue the 1 inch strip down 1 inch behind your fold, tear the paper off the top. Remove the paper from both side of the second strip and glue it on top of the first with a little bit hanging over the front. This is a change from the Armin method. I felt that with the shorter cord, removing more paper and creating a thinner section would work well. I also always make my top strip slightly wider to help form and support the airfoil. Once the stips are glued down, bend the top section over and check to be sure you like what you have. You are now going to have to cut the inner section of the top of the wing so it will fit over the tail section. It is now also time to start sanding the trailing sections of the lower wing. To do this I removed 3/4 of an inch of paper and then used a drywall sanding block. It goes fast and I get a good clean section.
You can see the formers glued to the wing, and how the lower section of wing looks sanded. At this point it took a bit of thought to figure out the middle section, but if you think about how the top section glues to the bottom and recognizing you want a smooth transition it makes sense.
fold the top section of wing over and mark where it meets the trailing edge of the lower section of wing and draw along the edge of the tail section. Draw a line between the two points you found where it met the trailing edge. This is not where you want to cut. You want to draw a parallel line 3/4 of an inch toward what will be the front of the plane. This is the section you will cut out.
This is the cutout I made in the back upper section of wing to fit over the tail section. The original mark where the upper wing meets the trailing edge of the lower wing has been cut away but you can see the ends of the parallel line I drew that was 3/4 inch past that point. Now draw another line 3/4 of an inch beyond that (the green line in the photo) and sand this middle section down just like you sanded the trailing edges of the bottom wing section. Once this is done, fold the top section over again and everything should blend nicely into the bottom section of wing.
Tip #2 I find myself needing to cut or draw parallel lines all the time in my building, so instead of using a metal ruler, I found a clear ruler in a fabric shop that is 6 inches wide by 24 inches long. It is marked every 1/8th inch in all directions and this really makes building easy. No measuring and marking needed, just line it up and cut.
Now put hot glue on top of the former and fold the top wing section over and hold. Just glue to the former first. Once you have that glue down the section across the tail next. then finally glue each wing. Once it is glued down you can cut the ailerons to size, mine are 1 1/2 inches wide. I can't improve on the Armin technique here, so if you don't know how to do it check out the Armin Wing Build video on Youtube.
The rest of the build is just like the original Bloody wonder build. I took the fuselage and vertical stabalizers right from the flite test plans.
Cut your elevator and glue these parts on as in the original instructions. Servos mount exactly the same way also.
The build goes fairly quickly if you have built the Bloody Wonder and an Armin Wing prior to this. Most of my time was spent measuring my sons planes and figuring out how to get it all to work out. That has been done for you, so this build really should take less time than the flite test version. I also prefer the tail being cut from the same piece as the wing. Both of my son's Bloody Wonders develop a slightly wobbly tail after a few flights and I do not think this will do that. I am not concerned at all about wing strength because I have used this extension method with much larger wings and have had no issues at all with then coming apart at the joint.
Here is our current fleet with two Bloody Wonders in the background with my new Flite Test Swappable Bloody Sullivan Armin Wonder in front.
* You can see a crease about 3/4 of an inch behind the leading edge. If you remember to remove the paper before you press the upper section over the formers, this should not happen, you should get a smooth curve.
Let me know if I forgot to tell you anything important!!
Log In to reply