GLider problem???? please read

[b3guyRC10]

well the sailplane forum has died, but i have a house of balsa 2x4 glider. My problem is that i cant really get it to turn and i have it set for the maximum rudder throw, i estimate 2inchs when the recomended is 1 inch. Could it be that i am throwing it off a hill which is about 25ft high, and not getting enough speed?

[Dave Robelen]

Hi,
How tight a turn are you getting? The 2X4 does need pretty good speed compared to lighter models, and the turn radius will be a bit larger. Also, is your dihedral the same as called for?
Regards, Dave

[b3guyRC10]

i built it exactly as the instructions specified. I give it full rudder for several seconds and it doesnt turn? would it be possible to put airelons on it. I have 4 channel radio and extra servos from my cars.

[Dave Robelen]

Hi,
Many of the glider designers use ailerons for just that reason. I would make them 15% the width of the wing with more up movement than down. It is puzzling that the model does not turn at all. It has been quite a while since I have seen a 2X4, so maybe there is some design problem. especially if you can see the rudder moving without response.
Regards, Dave

[imsofaman]

Could it be that the CD is too far aft? Maybe you are almost stalling? I would do a CG check.

[b3guyRC10]

i checked the CG and it is fine, and when i toss it, if glides fine. now i am decideing on how to make the airelons function. Put them on the wing is easy, but i can not decide how to hook them up?

[Dave Robelen]

Hi,
There are a couple of choices. Two micro servos could be used, one on each aileron and connected to the receiver with a "Y" connector. A mechanical drive would probably work best as a torque rod fro the center servo the the ends of the ailerons.
Regards, Dave

[imsofaman]

The great thing about using two micro servos (one for each aileron), is if your radio allows......you can program in the use of flaps which makes landing so much easier! I have done this once and worked great. Or do as dave had suggested using the torque rods using one servo to activate the two ailerons. I would go one step further by fabricating some spoilers mounting them on top of each wing to slow you down. I use the No. 1 channel (throtle) and reverse it. So when I go full throttle, the spoilers are down flush with the wing.....as you pull back on the throtle the spoilers raise slightly, slowing down the plane. So when the throtle os shut off, the spoilers are vertical. You would actually have a natural speed control! I plan on doing exatly that on a old Gull 1800 I have.

Dave Surace

[imsofaman]

Another thought.....fabricate a larger rudder, not familiar what the shape of yours is but maybe more square inches will help turn it easier.

Dave Surace

[imsofaman]

A quick drawing....if I had more time it would look better but I think you will understand,,,,

Dave Surace

[b3guyRC10]

well i heard from someone that i have WAY to much rudder throw and that its acting more of a air brake than a rudder. HOw do you measure the control throw, is it 1 in on each side or in total, because i have about 2 in on each side. Also is the 2x4 glider supposed to be a good flying plane, and do you have experiance flying it?

[Dave Robelen]

Hi,
The most accurate way to measure control throws is in degrees. Anything past 30 deg. is wasted, and could be causing drag. The measurement in inches depends on the width of the control, so it is hard to judge from that. It would seem like if you had too much throw, you could check that by only moving the stick part way.
I have no direct personal experience with the 2X4, but several friends enjoyed them, and it was popular as a slope glider when it was first introduced some years ago. I wish I could look your plane over, there is something that is slipping through the cracks. If your plane has ample dihedral, and the rudder actually moves in flight (no flexible linkage) it really should turn. Do you see it skidding in a slip when you apply rudder?
Regards, Dave

[b3guyRC10]

yes i am using flexy pushrods, but tomorow i am going to dial out some throw, and going to try it out. i do remeber than when i first flew the plane and had less throw that i could get it to turn preety well.

[rcfreak1215]

I think you problem may be airspeed. If you don't have enough air moving over the surface of that rudder then all it's going to do is slow you down even more. My advice is throw it from something higher to get more speed.:D