Trouble with stalling and climbing

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stephanwright2
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Trouble with stalling and climbing

Post by stephanwright2 » March 2nd, 2020, 5:38 pm

Hi, so it my first year and my partner's first year doing wright stuff, and we definitely don't know how everything works. Our plane is a monoplane from the freedom flight kit but we're not the best at building and the wing got a little warped and the winglets and rudders are pointing in a bit. Is that a big issue?

We think our plane is stalling because at times it looks like it is about to climb with the nose pointing up but then it suddenly drops a little and just continues on that level. Our plane also has not been climbing at all after it's been launched. Our plane flies for about 9-10 seconds and it only does that much because it makes a pretty wide circle. Mainly we have been trying to change the center of gravity and wind incidence.

As for some information about the plane, it is around 22 inches in length and we have been using a .058" rubber that is around 30.9 inches. We don't have a torque meter or anything but we usually wind it so that there are around 1000 motor turns available. Our winder has a 1:15 ratio so we usually turn it around 70 times. We increased our wing incidence about .45 cm and that seems to be working well compared to some of the other ones we tried. For left turns, the freedom flight kit comes with a protractor on the tail so have put the horizontal stabilizer .5 cm from the left end of the protractor. I'm not sure how else to describe that, but let me know if it doesn't make sense. We also put a shim underneath the horizontal stabilizer with the hopes of creating an "up elevator." It has helped keep the plane from nosediving, but our plane certainly hasn't been climbing.

Does anyone have any suggestions to the above problems or really anything about our plane that seems off? Any help at all is appreciated, and let me know if you need more information!! Thanks!

jinhusong
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Re: Trouble with stalling and climbing

Post by jinhusong » March 2nd, 2020, 8:43 pm

Some guess:
If you are using the prop coming with the kit (no pitch adjust), the 0.058" rubber is too thin. Please try the thickest or possible, get some even thicker rubber from last year.

You may need to adjust the CG if you cut the thickest rubber same length, not the same weight.

bjt4888
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Re: Trouble with stalling and climbing

Post by bjt4888 » March 3rd, 2020, 6:36 am

stephanwright2 wrote:
March 2nd, 2020, 5:38 pm
Hi, so it my first year and my partner's first year doing wright stuff, and we definitely don't know how everything works. Our plane is a monoplane from the freedom flight kit but we're not the best at building and the wing got a little warped and the winglets and rudders are pointing in a bit. Is that a big issue?

We think our plane is stalling because at times it looks like it is about to climb with the nose pointing up but then it suddenly drops a little and just continues on that level. Our plane also has not been climbing at all after it's been launched. Our plane flies for about 9-10 seconds and it only does that much because it makes a pretty wide circle. Mainly we have been trying to change the center of gravity and wind incidence.

As for some information about the plane, it is around 22 inches in length and we have been using a .058" rubber that is around 30.9 inches. We don't have a torque meter or anything but we usually wind it so that there are around 1000 motor turns available. Our winder has a 1:15 ratio so we usually turn it around 70 times. We increased our wing incidence about .45 cm and that seems to be working well compared to some of the other ones we tried. For left turns, the freedom flight kit comes with a protractor on the tail so have put the horizontal stabilizer .5 cm from the left end of the protractor. I'm not sure how else to describe that, but let me know if it doesn't make sense. We also put a shim underneath the horizontal stabilizer with the hopes of creating an "up elevator." It has helped keep the plane from nosediving, but our plane certainly hasn't been climbing.

Does anyone have any suggestions to the above problems or really anything about our plane that seems off? Any help at all is appreciated, and let me know if you need more information!! Thanks!
SW,

In addition to the recommendation above regarding rubber thickness, you can put more turns in the motor. See airliner posts in this forum thread for details on the turns estimation equation and winding technique. With the rubber motor properly wound to 80-85% of breaking turns, you should reset trim to the kit recommendations and backoff wind to low torque for first flights. A 31” loop of .058” rubber (if typical density) will take over 4,100 to 4,400 turns. Also see the 2015 archive topic “Winding”.

Brian T

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Re: Trouble with stalling and climbing

Post by bjt4888 » March 3rd, 2020, 6:37 am

Earlier not “airliner”. Poor autocorrect.

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Re: Trouble with stalling and climbing

Post by retired1 » March 3rd, 2020, 7:29 am

With 2,00 turns ,you are on the back half of available power, so the plane should fly level in a slight descent.
It is hard to disagree with Brian, but my experience and from some ancient literature is about 100 winds per inch of loop, or about 3,100 total winds to a point just slightly below the breaking point of the band. That assumes proper winding. Proper stretching of the band before it's first use is necessary. I personally like to stretch the band during initial part of the winding to about 6 to 10 feet for your band. gives much smaller knots, so you get more turns.
Build or buy a torque meter. It is well worth it.

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Re: Trouble with stalling and climbing

Post by stephanwright2 » March 5th, 2020, 8:53 pm

Thank you so much to everyone! My partner and I tried this and our plane climbed so much more than we thought it could. We have to do some adjustments, but this was so helpful!!

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