Wright Stuff C

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bjt4888
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Re: Wright Stuff C

Post by bjt4888 » March 1st, 2020, 1:50 pm

buildergirl wrote:
March 1st, 2020, 9:33 am
Hi! I've never posted in this forum but regularly read it and have definitely learned a lot in the process, so thank you.

We currently have 2 Freedom Flight monoplanes that work decent under the right torque (torque of 0.25 oz gets around 1:30 in 24 ft), however with higher torque we experience a lot of the problems described earlier in the forum including power stalling and diving into the ground. I read about the wing wash-in and I know there is a shim included in the kit to help with that, but I feel like I'm not alone when I say I have no idea how to use and connect it to the plane. The instructions on that part are a little unclear and many of the teams I've talked to don't really understand it as well, so have omitted it. However, I think it is time to figure out how to use the shim as our state is in 90 ft and our planes need to be able to handle the torque. If anyone has a visual on how to use the shim it would be greatly appreciated, or an alternate way to fix the high torque problem.

Also, I was wondering what our first change should be when trimming (incidence or cg?). I usually leave the incidence the same and just move the wings backwards or forwards to adjust the cg, however I don't know in what situation you would change each one to optimize the trim. Speaking of which, how do you know when the trim is optimized (whats should the climb, cruise, and descent look/time like?). Sorry for so many questions, many of which have probably already been answered, but I would really appreciate the help!
Builder,

Send details of all current trim settings and flight character: CG location (measured from the wing trailing edge TE), wing incidence (difference between wing TE to fuselage top edge measurement and wing LE to fuselage top edge, rudder offset measurement for both directions, any twist in the wing (eyeball it and estimate, ex. 1-2 mm left wing TE lower than LE), rubber weight and length (measure before winding for the first time; or if wound already, indicate how many times),number of turns on rubber, number of backoff turns, maximum torque before backoff, flight circle size, nature of power stall and drop (is it rolling to the left when diving or stalling straight ahead and then diving), propeller type and blade pitch angle.

With this information, we can give specific help.

Brian T

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Re: Wright Stuff C

Post by jinhusong » March 1st, 2020, 2:11 pm

buildergirl wrote:
March 1st, 2020, 9:33 am
Hi! I've never posted in this forum but regularly read it and have definitely learned a lot in the process, so thank you.

We currently have 2 Freedom Flight monoplanes that work decent under the right torque (torque of 0.25 oz gets around 1:30 in 24 ft), however with higher torque we experience a lot of the problems described earlier in the forum including power stalling and diving into the ground. I read about the wing wash-in and I know there is a shim included in the kit to help with that, but I feel like I'm not alone when I say I have no idea how to use and connect it to the plane. The instructions on that part are a little unclear and many of the teams I've talked to don't really understand it as well, so have omitted it. However, I think it is time to figure out how to use the shim as our state is in 90 ft and our planes need to be able to handle the torque. If anyone has a visual on how to use the shim it would be greatly appreciated, or an alternate way to fix the high torque problem.

Also, I was wondering what our first change should be when trimming (incidence or cg?). I usually leave the incidence the same and just move the wings backwards or forwards to adjust the cg, however I don't know in what situation you would change each one to optimize the trim. Speaking of which, how do you know when the trim is optimized (whats should the climb, cruise, and descent look/time like?). Sorry for so many questions, many of which have probably already been answered, but I would really appreciate the help!
Hi,

At high torque, fast speed, the turning is decided by the wing warp.

For the shim, for example, for left turn, it should cause the left wing has bigger angle (wash-in). When you look from front, adjust the angle you are looking so that the leading edge and the tail edge of the right wing overlap each other, while the tail edge of the left wing should be 1/8" or 1/4" lower than the leading edge. If not, maybe increase the thickness of the shim, maybe need extra rubber band to hold the wing mount to the fuselage. Also make sure when the shim for right turn, the ring wing should have more angle.

To see if it is optimized, you check whether the banking is too much. As long as it almost leveled, it is good.

Also check in high torque whether your plane frame bent or warp or not.

Best,

Tiger

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Re: Wright Stuff C

Post by CookieMeeps » March 1st, 2020, 5:39 pm

Hi!

I have 3 questions:
1. What are the advantages and disadvantages of bi wing vs mono other than increased drag and harder to build?
2. Does changing where I put the hook for the motor stick on the fuselage matter?
3. What can I do to increase times if my plane already uses up all the motor?

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Re: Wright Stuff C

Post by xiangyu » March 1st, 2020, 6:19 pm

Apparently Golden Gate Science Olympiad Invite's 1st place plane was 5 min combined... :o :o :o
2020 Events: Wright Stuff, Gravity Vehicle, Circuit Lab, Boomilever, Ping-Pong Parachute, WIDI, Machines, Detector Building

BEARSO/SOLVI/Solon/UMich/Allendale
Helicopters: 1st/-/-/-/-
WICI: 33rd/-/-/-/-
Macines: 81st/-/-/-/-

Medal & Ribbon Count: 9
East Grand Rapids High School Team Captain

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Re: Wright Stuff C

Post by Airco2020 » March 1st, 2020, 6:23 pm

xiangyu wrote:
March 1st, 2020, 6:19 pm
Apparently Golden Gate Science Olympiad Invite's 1st place plane was 5 min combined... :o :o :o
What???? Is that real? I wonder what the ceiling height was.

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Re: Wright Stuff C

Post by bjt4888 » March 1st, 2020, 6:34 pm

CookieMeeps wrote:
March 1st, 2020, 5:39 pm
Hi!

I have 3 questions:
1. What are the advantages and disadvantages of bi wing vs mono other than increased drag and harder to build?
2. Does changing where I put the hook for the motor stick on the fuselage matter?
3. What can I do to increase times if my plane already uses up all the motor?
CM,

Welcome to the forum. You’ll find extensive discussion related to your questions in earlier posts in the forum. Reading the entire forum will only take a little more than an hour and this effort will move you forward in the project significantly.

Brian T

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Re: Wright Stuff C

Post by coachchuckaahs » March 1st, 2020, 6:46 pm

Airco2020 wrote:
March 1st, 2020, 6:23 pm
xiangyu wrote:
March 1st, 2020, 6:19 pm
Apparently Golden Gate Science Olympiad Invite's 1st place plane was 5 min combined... :o :o :o
What???? Is that real? I wonder what the ceiling height was.
According to the web site, https://goldengateso.com/announcements/, 30' ceiling.

The 5-minute may also be after bonuses. Still, very good, would have to be slightly over 2 minutes per flight. And it was not Troy (they got 2nd)

Coach Chuck
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Nationals Results:
2016 C WS 8th place
2018 B WS 2nd place
2018 C Heli Champion
2019 B ELG 3rd place
2019 C WS Champion
AMA Results: 3 AAHS members qualify for US Jr Team in F1D, 4 new youth senior records

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Re: Wright Stuff C

Post by xiangyu » March 1st, 2020, 6:50 pm

coachchuckaahs wrote:
March 1st, 2020, 6:46 pm
Airco2020 wrote:
March 1st, 2020, 6:23 pm
xiangyu wrote:
March 1st, 2020, 6:19 pm
Apparently Golden Gate Science Olympiad Invite's 1st place plane was 5 min combined... :o :o :o
What???? Is that real? I wonder what the ceiling height was.
According to the web site, https://goldengateso.com/announcements/, 30' ceiling.

The 5-minute may also be after bonuses. Still, very good, would have to be slightly over 2 minutes per flight. And it was not Troy (they got 2nd)

Coach Chuck
Yea I heard Troy was at about 3 min combined raw. (Also I think the 5 min might've been raw not sure tho)
2020 Events: Wright Stuff, Gravity Vehicle, Circuit Lab, Boomilever, Ping-Pong Parachute, WIDI, Machines, Detector Building

BEARSO/SOLVI/Solon/UMich/Allendale
Helicopters: 1st/-/-/-/-
WICI: 33rd/-/-/-/-
Macines: 81st/-/-/-/-

Medal & Ribbon Count: 9
East Grand Rapids High School Team Captain

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Re: Wright Stuff C

Post by OpticsNerd » March 1st, 2020, 6:53 pm

CookieMeeps wrote:
March 1st, 2020, 5:39 pm
Hi!

I have 3 questions:
1. What are the advantages and disadvantages of bi wing vs mono other than increased drag and harder to build?
2. Does changing where I put the hook for the motor stick on the fuselage matter?
3. What can I do to increase times if my plane already uses up all the motor?
I'll answer number one:

Biplanes in theory are significantly more efficient, but in practice it almost never works that way.

Here's the thing:
1. Biplanes in comparison to monoplanes are very intolerant to even slight imperfections in the building process.
2. Biplanes are incredibly unforgiving to breakage. In a handful of cases, what should be an easy to fix break can drop your times by a whole minute, meaning you've gotta spend hours re-trimming it.
3. The tiny stabilizer removes much of the efficiency gained from using a biplane.
4. Biplanes are WAY harder to trim. Because of how small the stabilizer is, biplanes are very prone to stalling since much of the lift is concentrated at the wings. They are also extra sensitive to even the smallest changes.

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Re: Wright Stuff C

Post by newflight » March 1st, 2020, 8:34 pm

xiangyu wrote:
March 1st, 2020, 6:19 pm
Apparently Golden Gate Science Olympiad Invite's 1st place plane was 5 min combined... :o :o :o
bi or mono?

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