Designs

[blue cobra]

Like in the LE kit, if turn is induced by things you can't change like stab tilt and wing warp, what do you do if the flight diameter is wrong?

And, how do you make the wing warp?

[jander14indoor]

Small changes, breath on the relevant component to heat and moisten, bend into desired shape, hold till cool and dry.

Larger changes, crack and reglue in new position. Note, this is how I set initial trim. This takes a little practice, but becomes quick, easy and stays solid with experience.
Its why I build a little underweight and bring up to weight with clay. I can remove or move clay as appropriate to stay at 7.0 gm and maintain balance point. But if you are careful, you can do a lot of corrections and not gain much weight. And I'm the weight fiend!

I actually don't mess with turn radius much. I tend to keep my circles on the medium side. Only reduce for very small rooms. I haven't found it paid to open it up for the real large sites, instead I use it to control where I'm flying in the site.

Jeff Anderson
Livonia, MI

[smartkid222]

i wouldn't recommend wing warp as there are many other things that can be done to induce a turn. some of these include

1) if using a saddle system or wing posts, they would be on the left side of the fuselage
2) horizontal stabalizer is tilted (stab tilt)
3) propeller is mounted a few degrees to the left
4) vertical stabalizer/ fins are used
5) Connect motor stick to the tailboom at an angle.

[andrewwski]

Often it's best to combine a number of different techniques though.

You definitely don't NEED wing warp. It will fly and turn with the use of other methods. However, wing warp may help you with trimming - it may give you a nicer or smoother turn, etc.

My best plane used wing warp. The trailing edge of the port side was lowered about an eighth of an inch. This was combined with an offset wing and slight angling of the prop. It had a level stab with tips, no vertical rudder. The wing warp definitely made it fly better, but the flight time probably would not have been much less if it was not present.

There are numerous things you want to try when trimming. It all comes down to practice, and getting a feeling for your plane.

And I always found that breathing on the spar was plenty to allow it to be bent slightly. You don't want to be using super dense balsa for the spars anyway.

[carneyf1d]

I'm pretty sure wing warp causes drag. So i'd use other turning mechanisms before you switch over to warping

[danyalukin]

Making the plane turn never was a problem for me, however, i was always having problems with TORQUE in the beginning of the filght.
What can be done about that? The kits propose wing warp and positioning the wing right of the fuseladge (looking from the front), but wouldnt that interfere with the turn? I tried both, but it doesnt seem to be efficient...

Daniil

[carneyf1d]

Offsetting the wing by a quarter inch should do the trick...make sure you're putting the offset on the correct side. also try some dewinds if that doesnt do the trick.

[danyalukin]

I assume offset in the direction of turn right?

[carneyf1d]

yep

[gsimmons12345]

can i have pictures of former winner designs

[andrewwski]

Wright Stuff Image Gallery
The Best of 2009: Wright Stuff

[mg]

Hi

I opened the Freedom Flights Model today and I noticed 2 things diffrent than last years model:

One was not having the wire connector. Besides adjusting the wings how would you adjust your plane now?

Secondly, I was wondering if not having the diheadral is bad.

Thanks
MG

[blue cobra]

Not having any dihedral is bad. Dihedral is used to stabilize your plane. Without it, a slight upset in flight, perhaps just from turning, will not be recovered from and could be accelerated. To describe this, I will steal a paragraph from the pdf linked to below:
"To describe how dihedral provides lateral stability,
try to visualize the airplane’s wing not moving but having a flow of air pass over it. If the wing is held so that the air passes at right angles to the LE, it is the same as it would be when the
airplane is flying straight. However, if
the wing is rotated to the side so that
the air passes at an angle to the LE,
it is the same as the airplane
flying in a circle. When the wing
has dihedral and is angled to the
wind, there will be more wind under
the side of the wing that would correspond
to the inside of a circle and also more
wind above the side of the wing that would
correspond to the outside of the turn. This
difference counteracts the tendency of the
airplane to go into a spiral dive in the same
direction as it was circling."

You don't necessarily need one dihedral point in the center of the wing, however. You can have two dihedral points with a horizontal center, like the picture in the pdf. Or use tip plates, which basically are an extreme form of two dihedral points, with the tips going straight up. Some have also had success with little or no dehedral on the wing, but some form of dihedral on the horizontal stabilizer. This will be less stable than dihedral on the wing, but it may be stable enough for a wind-current-controlled gym.

pdf: http://soinc.org/sites/default/files/up ... iad5.0.pdf

[jander14indoor]

<SNIP>One was not having the wire connector. Besides adjusting the wings how would you adjust your plane now?<SNIP>

Is there some way to adjust the angle of attack of the rear stab, like post in tubes? If so, you don't need much else.
The wire let you adjust stab angle of attack and tail boom offset.

Frankly, most people adjust boom offset once and leave it. Its one, but only one, of the determinants of circle diameter. I generally set mine so that for a reasonable size circle the wing spars and stab spars run along radii for the avg circle size to minimize drag. A little geometry lets you figure out how much offset for your design, good plans give this to start. Hope that makes sense. If I really need to change it for a site, I just crack and reglue the boom to a new offsetg. Takes about a minute with superglue and setter (and a little practice) and you are back flying.

I adjust stab angle of attack much more often, sometimes VERY small tweaks make all the difference here. You can glue one stab spar to the tail boom and have the other ride on a stick sliding up and down in a tube. Or have both ends set up like this. Same thing as a wing mounted on sticks in tissue tubes. Needs to have enough friction to hold the setting, but not so much you can't remove. I actually find this much easier to collect data on as I just measure were the stick is in the tube. Very easy to measure directly with a simple ruler.

Jeff Anderson
Normally in Livonia, MI, but temporarily in Burlington, ON, Canada for my job.

[gh]

Also, you can adjust the offset and "twist" of the tail boom just by wetting it (with saliva, if in a pinch) or breathing on it, then bending or twisting slightly. Holding it in place for a while will help it set. This worked well for me when I first started, with Ray Harlan's Lil' Dipper, which had a fairly low-density one-eighth inch square tail boom.