Thread: Build Log Portable indoor plane
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Old Jan 29, 2013, 11:06 PM
slebetman is offline
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Malaysia, Selangor, Kajang
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Quote:
Originally Posted by Jimmy JFlyer View Post
But then I come across this and the thought of FF rubber powered in the family room is just too cool to pass up.
I have never done a stick & tissue or anything similar before but now am excited to try it.
Would you be able to give a materials list & maybe short build log?
I will do some easy kits first to get some stick build time before trying something like this. I am sure its got to be trimmed just right and the angles just right to perform like your does.
That's great. I was a pure foamie guy too. In fact I built several foam rubber powered planes before I started working seriously with balsa. Foam is still quite a good material but it's hard to get the weights I'm getting with balsa using foam. This plane for example is only 1.2g minus the rubber. And that's with the heavy plastic prop.

Materials list:
1. 1mm balsa for everything. I'm using cheap balsa from the art shop that architecture students use to build 3d models of buildings. If you have good light balsa then 1/16" should do just fine. 1mm is roughly 1/24" btw.

2. Covering is thin vegetable bag from the supermarket or grocery store. Just pocket a couple extra bags the next time you go shopping. An alternative is saran wrap/clingfilm but it's a bit heavier and much harder to work with because it clings to everything.

3. Metal bits - prop shaft, prop hanger & tail hook - No2 guitar string. They're cheap so get a few because you're going to waste a lot the first time you try to make the prop hanger and prop shaft.

4. Prop - thin plastic cup. The kind they sell bubble tea in. Some of the cheaper ones are thinner and lighter.

5. Glue - CA/superglue. I use the cheapest I can get my hands on. This is the one big difference between balsa and foam. Foam is cheap but foam glue can be quite expensive. Balsa is expensive but the glue is cheap.

6. Rubber. This is the only thing that you can't skimp on. Get good quality free flight rubber. The traditional vendors are:

http://www.shortysbasement.com/
http://www.faimodelsupply.com/
http://www.a2zcorp.us/store/

A plane that flies for 15 seconds or so with regular rubber bands will fly for more than 2 minutes with good rubber.

I'm flying my plane with .040 rubber but get yourself several sizes since selecting rubber thickness is part of trimming a rubber powered plane. When I started out I had only two thickness of rubber: 1/8" and 1/16" so I did the opposite: I tried designing planes that would fly well with the rubber I had.

Eventually you'll want a rubber stripper so that you can optimize the rubber to your plane but they tend to be expensive. The next best thing is to find a friend with a rubber stripper, which is what I did ;-). The next best thing after that is to simply buy rubber in a bunch of different sizes.

Now, some tips I've learned from experience.

I've accidentally found that 10" wingspan is great for living room flying. There is actually an official AMA class that is called the Ministick that was intended for living room flying and the maximum wingspan for the class is 7".

Give your plane plenty of dihedral. It's not for stability - at least not what you think. It's for spiral stability. Not enough dihedral will cause your plane to spiral to the ground on launch.

Don't use the rudder to turn. Instead, tilt the horizontal stabilizer in the opposite direction of the turn. Or looking at it another way, tilt the wing into the turn. Basically pre-bank the wing. As the rubber winds down and the plane starts to fly slower the rudder completely loses effectiveness. What happens if you trim to turn using the rudder is that the plane will start flying straight when it comes down which will cause it to hit a wall.

Give the wing on the inside of the turn (the left wing for left circles) some wash-in. This increases the lift in that wing allowing you to trim your plane to fly tighter circles - which is what you want if you want to fly in your living room.
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