Wright Stuff C

lechassin
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Re: Wright Stuff C

Postby lechassin » January 15th, 2020, 12:53 pm

Wow, 55% is way more aft than we can use. Our CG is at 30% and the planes cruise level with only 3-4mm decalage, and they recover adequately, not superbly, even with a tail moment 5x wing chord (42cm).

At 55%, do the planes need negative decalage? Can they recover from a hit at all :?

poinsettia3432
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Re: Wright Stuff C

Postby poinsettia3432 » January 15th, 2020, 7:29 pm

Hi everyone! I've built the Freedom Flight kit as a monoplane and have been having some trouble getting it to turn in both directions. Strangely enough, the plane likes to turn clockwise and can fly fairly well in that direction. However, when I attempt to have the plane turn counterclockwise, it nosedives. It also seems to be tilted when in the air (one wingtip is higher than the other). I'm fairly certain there's not an issue with the angle of attack or center of gravity, because the plane is pretty much balanced when turning clockwise. I've already tried lots of adjustments with the shim and horizontal stabilizer/rudder position, but I was wondering if anybody had any tips that I may have overlooked. Thanks for the help!

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Re: Wright Stuff C

Postby coachchuckaahs » January 16th, 2020, 9:08 am

Hi everyone! I've built the Freedom Flight kit as a monoplane and have been having some trouble getting it to turn in both directions. Strangely enough, the plane likes to turn clockwise and can fly fairly well in that direction. However, when I attempt to have the plane turn counterclockwise, it nosedives. It also seems to be tilted when in the air (one wingtip is higher than the other). I'm fairly certain there's not an issue with the angle of attack or center of gravity, because the plane is pretty much balanced when turning clockwise. I've already tried lots of adjustments with the shim and horizontal stabilizer/rudder position, but I was wondering if anybody had any tips that I may have overlooked. Thanks for the help!
P:

Which way is the plane tilted when flying a left (CCW) circle? I suspect inward (left wing lower). In that case, you need to introduce a bit of wash in to the left wing. This means the left wing tip will have more incidence than the right wing tip. I do not know how this is done on a FFM plane, I have not built one.

The reason for the difference is the torque of the prop, which is the same (wants to roll left) regardless of turn direction. So the setup will not be the same in both directions. In addition, you may find that the incidence needs to change as well. The trim in each direction may be substantially different due to the asymmetry of the propeller torque.

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jinhusong
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Re: Wright Stuff C

Postby jinhusong » January 16th, 2020, 9:19 am

Hi,

You may need to adjust the wing pitch (your angle of attack) when you switch between left and right turns.

In our case, we need to adjust: rudder, shim, and wing pitch.

Also, after switch the shim, please visually check the wing warp, make sure it is in right direction and reasonable amount. You can play with the shim position (up down a little) to adjust the warp.

Tiger

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Re: Wright Stuff C

Postby nobodynobody » January 16th, 2020, 9:40 am

Hi everyone! I've built the Freedom Flight kit as a monoplane and have been having some trouble getting it to turn in both directions. Strangely enough, the plane likes to turn clockwise and can fly fairly well in that direction. However, when I attempt to have the plane turn counterclockwise, it nosedives. It also seems to be tilted when in the air (one wingtip is higher than the other). I'm fairly certain there's not an issue with the angle of attack or center of gravity, because the plane is pretty much balanced when turning clockwise. I've already tried lots of adjustments with the shim and horizontal stabilizer/rudder position, but I was wondering if anybody had any tips that I may have overlooked. Thanks for the help!
The plane is having trouble going counterclockwise because the propeller applies a torque and twists the entire plane that way, since it tilt in a lot. Since it tilts in more it looses lift and has the tendency to nosedive. Changing the rudder angle worked the best for me, it was just a tiny bit off center so it doesnt turn too much.The center of gravity will also be different than the clockwise turn. Hope this helps!
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ryanscioly
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Re: Wright Stuff C

Postby ryanscioly » January 19th, 2020, 10:18 am

Hey I’m new to Wright Stuff and I was wondering how I can find out the maximum number of winds of my motors without actually snapping them, so I can get the best performance from them. I am currently testing out .058”, .065”, and .072” rubber from Freedom Flight Models. Also, when winding, should I primarily use the torque of the motors or the number of winds to know when I should stop? Thanks for any help in advance!

lechassin
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Re: Wright Stuff C

Postby lechassin » January 19th, 2020, 12:43 pm

Last gym session before 2nd invitational next week. Primary plane, 2.8 grams 0.0625 ,1'55" to the left with one banner hit and good recovery with 2nd climb (0.3 in.oz), 1'45" to the right (0.27 in.oz) , we just put that one away to avoid damaging it.

Backup plane, we spent the entire session trying to figure out why it needs the CG more forward by 3mm with 1mm additional decalage both ways, resulting in 1'25" to the left, 1'45" to the right. A good 15 seconds less due to the extra decalage's increased drag , aaaand...

...it turns out that this backup plane, also being Luke's practice plane, gained 0.3 grams from repairs, and we didn't notice till we got home today :oops: . I couldn't resist removing 0.3 grams of ballast, so of course the plane is now very likely to be out of trim. I don't dare match the primary plane's settings without testing. The hopeful plan for next week is for Luke to test fly the backup plane first to master the venue and re-trim the plane, then test fly the primary plane to verify settings, and fly the primary plane officially.

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CrayolaCrayon
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Re: Wright Stuff C

Postby CrayolaCrayon » January 19th, 2020, 12:49 pm

...it turns out that this backup plane, also being Luke's practice plane, gained 0.3 grams from repairs, and we didn't notice till we got home today :oops: . I couldn't resist removing 0.3 grams of ballast, so of course the plane is now very likely to be out of trim. I don't dare match the primary plane's settings without testing. The hopeful plan for next week is for Luke to test fly the backup plane first to master the venue and re-trim the plane, then test fly the primary plane to verify settings, and fly the primary plane officially.
While extra weight is not desirable, .3 grams is not necessarily a ton of extra weight, and it is worth keeping the weight to maintain your CG. Better it flying a little less time, than for it to kick up the nose and stall on the launch pad.
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lechassin
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Re: Wright Stuff C

Postby lechassin » January 19th, 2020, 1:43 pm

Good point, I'll set aside the 0.3 grams and if he lacks the time to re-trim it, he can just put the weight back on.

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Re: Wright Stuff C

Postby CookiePie1 » January 20th, 2020, 4:04 pm

we're having trouble getting time in the gym, but i do have enough space in my basement for an unpowered glide. Is there any way to trim our planes in this limited space?
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