And here we are, with yet another exceptional "RCPowers Original"!
Mine is made from EPP, since I wanted to fly with it in my street.
It's a cul de sac with a little round yard in the middle, with some nasty trees, that have a very strong forcefield around them. (You know, the invisble force that pulls the airplane towards them, as like in the Battlestar Galactica,or was it Star Wars(?)series "tractor beam")
This is indeed a strange phenomenon, but model aircraft flyers around the world know it (unfortunately) all too well; even if you have an empty flying field with no obstacles and all the space whatsoever, but one single tree, where will the aircraft undoubtfully end up against?
So to make a long introductory short: regular depron was out of the question, sice it snaps upon impact. EPP was the way to go then.
One thing I was concerned about was the "floppyness" (for lack of a better word) of the EPP, by that I mean the amount that it can twist. And my concern turned out correct, when on the maiden flight I tried some moderate rolls, the tailend of the aircraft would literally stay in place until the fuselage and the wings had already rolled through 45 degrees, upon which the tail end finally started to follow the rest of the plane. Indeed a very strange and scarying sight to behold! (There is a carbonspar running lengthwise through the fuselage, which eliminates the lateral twist (sideways) but not the torsional one)
So after landing I did some searching on the RCgroups forum, and I found a post from someone saying that he put clear ducttape on his plane, and it made the plane realy stiff. I did not have clear ducttape laying around, but I did have a wide roll of so called "packingtape" (the clear type with white fiberstrands running through it)
So I decided to give that a go. A first I put the tape only on the right side of the plane, since I did not want to spoil the looks of it. (Of most of my planes the left side is the nicer "photo and display side", and the wires, batttery, servos, and the works are on the right side). The tape made all the difference in the world!!!
And another lesson I relearned, was that the tape can only be seen on the ground from close range, but in flight It magically disappears!
Which is sort of the same concept with the flat construction of the airframe, when in flight, (say further than about 10 meter (30 feet) away, when the "finer details" can't be seen anymore your brain tells you that it looks perfectly ok! (such as it would when it has a full 3D fuselage)
The way this works is that your brain "knows" what an airplane looks like, because of experience: ALL aircraft have a more or less round tubelike fuselage shape, so when your eyes cannot see an image that tells it is different in this case, the brain just "fills in the blanks" and turns it into a picture it Knows how it should look like!
(which is in fact incorrect, the brain is actually "lying" to us, what you perceive to see (a round 3D fuselage) is really NOT there!)
So I put tape on both sides now, and the plane is as stiff as, as... well what your wife is happy about when you wake up in the morning... ;-)
I put in some right and down thrust by offsetting the motor to the left and top in relation to the "firewall" (the wooden motormount where the motor is screwed on to), and by putting a washer under the left and top side between the wood and the metal mount, so the front of the motor axle ends up in the center. (the easiest to do this is to lay the wooden plate flat on the bench and while looking from directly above move the motor around (with the washers in place so that the center of the prop ends up in the middle of the circle of the wooden motormount, and when you have that, mark where to drill the holes. (I just eyeball it, this is no rocketscience, however by doing it this way i.s.o. glueing the woodenfirewall on tilted, one can adjust the amount of offset thrust by varying the amount of washers (so you start from a neutral point (since the wood will be glued flat ont the aircraft))
The only thing I am not happy about yet is the flying time, I get 4 to 5 minutes max from it, so I have to work a little more to optimize the power/prop/motor combo.
(Hobbycity 2408-21 (1400KV) motor, 18A ESC, 9x3.8prop, 3S 750mAh Rhino LiPo) I have an 8x3.8 prop on it now, it is a lot quieter, better for the neighbors! And the motor accelleration is a lot better, flying time is about the same...
The tape (and extra hotglue after some intense treecontact) made the plane about 30 grams heavier, it now weighs in at a hefty 324 grams. (was 293 gr.) So with the battery this makes it a total of 391 gr. AUW. (Quite heavy but I got the wrong foam, the 1.9 density, I should have ordered the 1.3 density...)
Here are the piccies:
http://www.rcgroups.com/forums/showt...0#post12341825
Best regards,
Martin
RCPowers FREE Extra300 PDF *FREE FMS MODEL ADDED*
Need more info on how to use 
bulding extra300
Linear Mode
