Circular

powerofpi
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Circular

Post by powerofpi » November 17th, 2014, 2:28 pm

Does anyone know how to get the wright stuff plane to fly in a circular motion and how to properly throw it?
Last edited by powerofpi on November 19th, 2014, 1:44 pm, edited 1 time in total.

jander14indoor
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Re: Circular

Post by jander14indoor » November 18th, 2014, 6:52 am

The answer is VERY different between Wright Stuff and Glider. Since this is the Wright Stuff forum I'll focus on that answer here.

Basically, you build the plane to fly in a left turning circle. Because some of the controls work differently at different speeds you have to have several things going on and will have to adjust the following recommendations to your plane and flying site. Oh, and you want to use the largest circle you can without constantly hitting the walls because it take energy to turn that is better used to increasing flight time.

OK, as a starting point, the following adjustments need to be made for a left turn.
First, the horizontal stab should be tilted to the right relative to the wing.This pushes the stab to the right and turns the plane left. For a normal maximum sized stab, the left side should be 1/4 to 1/2 inch higher than the right with the wings level.
Second, the vertical stab should be angled for a left turn. The easiest way to do this is to build the tail boom so that it isn't aligned with the motor stick. Looking down from above on a plan with say a 10 inch tail boom, you want the end of the tail boom about 1/2 inch to the left of the line the motor stick makes.
Since your left wing is flying slower than your right, you need to offset the wing to the left, 1/2 to 3/4 inch to recover the lift so your plane flies level.
Finally, you need the angle of attack of the left wing to be slightly higher than the right wing. This is called wash in where the tip of a wing is twisted to a slightly higher angle of attack than the root (center) of the wing. If your tip angle of attack is less than at the root its called washout. So, build the right wing flat and the left wing so the tip of the leading edge is raised about 1/8 inch higher than the trailing edge. This will require you to crack the front spar so it can bend at the root and reglue it.
Note, the last two items don't so much control the turn, as re-level the planes wing and allow it to climb better. These planes don't turn by banking as full size planes do, but more by sliding.

Now, fly. If your circle size is right, no issue. If too small, reduce the tilt of the stab first, then the kink in the tail boom. You can do this by cracking and regluing the tail boom. Leave the wing alone unless it is very obviously flying with the left wing high. If too large, add tilt and then add kink. If your plane is circling fine, but just doesn't climb well, check the left wing wash in, you may need to increase it. A very little change here can make a big difference in climb.

Hope that helps,
Jeff Anderson
Livonia, MI

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Re: Circular

Post by jander14indoor » November 19th, 2014, 6:19 am

Forgot one item in the list above. The propeller axis should be pointing down and left 2-3 degrees. Down is to tame the peak power available on launch. Left is to help the turn. You can actually be straight and down, but DON'T be pointing right for a left hand turn.

And I forgot to answer your question on how to throw it. For Wright Stuff you basically don't. Any throw is more likely to break a properly built and trimmed plane than help it.
For initial flights, hold straight and level at shoulder height with both hands, one on prop, one on motor stick. Release prop to allow it to come up to speed. A moment or so. Then give a gentle (GENTLE) push straight and level with the hand on the motor stick and release it. IF you are trimmed right it will fly immediately. If not, a hard throw won't help and will make it hard to interpret what the real issues are.
Once you have the plane trimmed well enough that you know it will fly level at least and preferably fly out of your hand, get on your knees and launch as close to the ground as you dare (remember, the first touch on the ground stops the time, so don't over do this, I generally launch about 6 inches off ground). The more room your plane has to climb the longer your flights will be.

Regards,
Jeff Anderson
Livonia, MI

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Re: Circular

Post by powerofpi » November 19th, 2014, 1:10 pm

Thank you so much for your reply. And also, how do you suggest to make it fly higher up. It flies level and then just flies semi-straight until it reaches the ground(it doesn't climb much).
Thank you once again.

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Re: Circular

Post by jander14indoor » November 20th, 2014, 6:27 am

Depends, need more information to answer your question. Note to all, the following info is almost always needed to give meaningful answers.

What design are you using? Wing and stab size? Weight of plane without rubber? Weight of motor? Width of motor? Winds at launch? What are your trim settings? What is the plane doing (which you already provided clearly, but this is meant to be a generic list of questions)?

With that we can give specific advice vs the generic advice you can find in this forum or the wiki or the archives.

Regards,
Jeff Anderson
Livonia, MI

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Re: Circular

Post by powerofpi » November 23rd, 2014, 8:54 am

The design is attached. The wing is 40 cm and the stab is 20 cm. Weight of plane without rubber and propeller is 3 grams.The weight of the motor with propeller is 4 grams and without the propeller is about 1.5 grams and the width of the motor is 23 cm. Not sure about the winds ant launch or the trim settings. The plane is flies smoothly and slightly circles but does not lift much at all. I have yet to test it in a larger gym.
Thanks for your advice.
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Re: Circular

Post by powerofpi » November 23rd, 2014, 11:47 am

The left wing is lower than the right and is adjusted to be 1 cm longer than the right wing. The LE is about 0.5 cm higher than the TE. The stab is slightly shifted to the right. The fin at the back is shifted to slant to the right. I built another main wing with curved ribs. Do you think that this will be better than the previous one with flat and straight ribs?

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Re: Circular

Post by jander14indoor » November 24th, 2014, 9:38 am

That prop isn't a very good one for these rules, too small and too heavy. It needs to spin really fast to provide enough power for these models, not really ideal.
And unfortunately I've had a hard drive crash and lost my e-copy of the rules, but isn't the max span 50 cm? I so you are giving up a lot of area for that mass and will have a harder time climbing.
The left wing wash in (leading edge high) seems a bit much, that might be preventing the turn of the other settings.

While not ideal, that plane should be able to fly better than you are describing.

We REALLY need to know something about your motor and winding.

I'm guessing too thin a motor not wound hard enough. Almost certainly not wound hard enough. That little prop really needs to spin fast to make that plane climb. Even when you get it climbing don't expect long flights (maybe a minute?), a fat enough motor to really spin that prop won't take a lot of turns and the rpm will run them out fast. OK to learn on, but not really ideal for competing.

Yes the curved ribs will help, but you'll get far more from a bigger wing and a better prop.

Jeff Anderson
Livonia, MI

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Re: Circular

Post by andrewwski » November 25th, 2014, 12:53 pm

Also, you mention that your motor is about 1.5 g. I believe the rules allow up to 2.0 g - so use it! The larger your motor, the more winds you can put in, and the more energy you can store.

I used that exact prop years and years ago. It's nowhere near as good as the Ikaras. But if you are stuck with it, you can lighten it significantly by shaving it down with an X-acto knife until you can see through it. But as Jeff said, you'll want something with a larger diameter.

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Re: Circular

Post by 28builder » November 28th, 2014, 7:25 am

hey thanks for all the great replies mr anderson. tremendously a

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