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Help! Designing an Airplane - My Big Plan

Is my plan a good one?

  • No! Stick to the proven methods!

    Votes: 0 0.0%

  • Total voters
    9
#1
I've been wanting to design my own foam board plane for some time now, and I've done research on topics such as general air frame design, wing design, appropriate motors and the like. It seems like a fun process, but also one that takes much time. I love designing things, but I also love seeing those designs come to fruition, and rather quickly at that. Can't have your cake and eat it too. This need to take lots of time, many weeks or month even, has kept me from actually starting anything.

So what's the plan from there? Until now, there hasn't been a plan. I haven't flown anything in quite a while, but am finally getting some time to start enjoying the hobby again. My thirst for designing a plane is back, and I've since had a new concept on how to go about doing it. I am a man of science, after all, and science is a good way to solve problems.

My big plan is to look at a couple of FT designs, take inspiration, and just build my own plane, strap a motor to it, and see what happens. I can easily access DTFB and the electronics are robust enough. I'm going to start hashing together some build plans with little thought into the efficiency of the actual design. Then I'm going to (attempt to) fly it.

What are your thoughts on this? Is this how its actually done? Obviously not with full-scale planes that could cause death due to poor planning, but what about foam board planes? Keep what works, toss what doesn't, right? Either way, consider this a scientific, experimental journey. I'm going to try to take pictures and notes and post them here as I make progress (or the lack thereof). Give me some feedback and some advice for the process!
 
#2
<Reserved For Progress>

Update 1 - So I've Drawn Some Plans

I finally got a chance to draw up some plans. I'm going for a warbird type style-low set wings, teardrop fuselage, etc. The wings are a tad long for a warbird, but it's the wing area that will give me the flight characteristics I'm going for, or so I hope.
It's a bit wonky looking, even in the drawings, but I'm just going to tell myself it's unique and my own. I'm planning on using Power Pack A and supposedly I'll be pulling ~125W on a 2-cell and ~190W on a 3-cell, but I don't know, this is the first time I've actually run that equation. On the drawings, one square is equivalent to four square inches, so each square is two inches long/wide. Have not yet designed a specific foil for the wing. No dihedral or polyhedral are currently in the works, but definitely not out of the question. What do you think? All criticism welcome!
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Update 2 - Some Bad News
I have two 12a ESCs and they both happen to be burnt out. Until I can get another one, this project is on hold. Fortunately this gives me time to build an FT Simple Storch so I can relearn how to fly, as well as allow me to redesign the obese fuselage. It's a 4"x4" nose swinging a 6" prop. You can see how that may not have the best flight capability. I'll need to cut that width in half and raise the motor mount. On the plus side, I did open up Google SketchUp to get a 3D representation. Despite the large fuselage, it actually looks pretty good! Updates to come.
 
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#3
Cool! Designing ist a ton of fun, just give it a go! My best tips are dont go too crazy and keep it simple to get easy success. And design it as conventional as possible.
Also post some drawings to show your concept!
 

foamtest

Toothpick glider kid
#4
I would loosely base it off of a current design in terms of wing area, wing span, tail surfaces, etc.. but change on thing at a time to see how changing that one thing affects the airplanes tendencies in the air. A pretty bad example is when I crashed my biplane and the top wing came off so I tried to fly it with the much smaller bottom wing. It was insanely nose heavy and flew stupid fast. So what I learned is when you reduce the wing surface area then the plane has to fly much faster to create enough lift to stay in the air. I also learned that when a plane is very nose heavy the elevator control becomes very anemic.

It was a very unscientific example but it is one none the less.
 
#6
Sometimes the plans that you think would fly the worst fly very well. Its only foamboard so just throw some stuff together and strap a motor to it. And if you ever feel discouraged just take a look at the nutball. If that thing can fly what can't!
 
#7
Thanks for the encouragement, guys! I'll be drawing up some plans soon, and will probably hit Dollar Tree with a twenty dollar bill. I want to design something stupid simple and just modify it almost in a modular system to isolate changes and make them easily reverted, or in the event of a catastrophic (I also use the word "awesome") crash, rebuild-able as well. The electronics can take a beating and foam board is cheap, so like I've said many times before: The most efficient way to find the limit is to pass it by. Fold the wings! Rip off tail segments! Push the envelope! Updates to come.