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Old May 02, 2012, 11:24 PM
Smoke me a Kipper
fritzdecat's Avatar
Cedar Grove North Carolina
Joined Oct 2006
1,214 Posts
tail heavy and it noses in? did he mention a stall ?

video the launch Mr Rub

get to the bottom of this
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Last edited by fritzdecat; May 02, 2012 at 11:32 PM.
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Old May 03, 2012, 12:28 AM
New Beeeeee
RUBNorris's Avatar
United States, CA, Sacramento
Joined Apr 2011
1,097 Posts
I'll try to post a flying video on my lil' prob. tomorrow it's going to rain but i'll try to get out. It's just hard to see everyones plane fly sooooo well and mine gives me a head ach. lol
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Old May 03, 2012, 01:07 AM
wheeeeee!
elCapitan's Avatar
United States, UT, Provo
Joined Oct 2011
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I still think we need to get to the bottom of the CG question. How are you measuring CG?

Remember, CG isn't something you can just choose to move around. Depending on the shape of the airfoil, surface area, etc, the CG is calculated to be inherently at a certain point. How you build your plane will make it either nose heavy, tail heavy, or balance on CG. The reaper's CG is 10.5" back from the nose.
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Old May 03, 2012, 09:01 AM
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Quote:
Originally Posted by elCapitan View Post
I still think we need to get to the bottom of the CG question. How are you measuring CG?

Remember, CG isn't something you can just choose to move around. Depending on the shape of the airfoil, surface area, etc, the CG is calculated to be inherently at a certain point. How you build your plane will make it either nose heavy, tail heavy, or balance on CG. The reaper's CG is 10.5" back from the nose.
I think you are confusing people>>The CG is the Centre of Gravity and that is where each individual wing really balances by definition.

Remember, CG isn't something you can just choose to move around.

The actual CG will be moved depending on how the wing is built>> you move the CG by moving weight ( usually Batt ) towards nose or tail

We need to build so that the actual CG is where its planned to be after the plane is finished.

I suggest we need to agree the planned or target CG ( or a range ) for each model and build to that?

~~~~H
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Old May 03, 2012, 09:18 AM
wheeeeee!
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United States, UT, Provo
Joined Oct 2011
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Yes, you're right. We're saying the same thing with different words. Technically any object in the world has a center of gravity--the point at which it balances--but what I mean is that the "proper" (or as you say, "target") CG for the Reaper is 10.5", and that's where CG should be. That's what you can't just change because you feel like it. I could build a Reaper that balances 3" behind the nose (and you'd say my CG is at 3", and you'd be right), but my CG is wrong. If I held it up and tried to balance it at the proper CG, 10.5", I'd find out that I'm actually very nose heavy.

In the video, he says, "I put the CG up here because I wanted to run two batteries" and points at the nose, about 4" back. That right there makes me think there's something wrong with how it's being measured.

SO... for RUBNorris, my question is, how are you measuring CG? In other words, if you measured back 10.5" from the nose, then used a square or something to extend that point out to the sides, then tried to balance your Reaper along that line, what happens? Does it tip forwards or backwards, and how badly?
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Old May 03, 2012, 03:45 PM
McCleary.11's Avatar
United States, OH, Delaware
Joined Mar 2006
757 Posts
I have seen the CrashTestHobby video for proper take offs (and apparently didn't learn anything). Can I be the star if the video for incorrect take offs comes out?





5 stitches... Keep your fingers out of the prop! I was lucky it wasn't much much worse.

I have the entire thing recorded with my GoPro! I will post it up later...



On a positive note, I maidened my Reaper XL and it flew Great!
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Old May 03, 2012, 03:56 PM
wheeeeee!
elCapitan's Avatar
United States, UT, Provo
Joined Oct 2011
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You're not cleaning the blood spatters off the elevon, are you!?

Glad the DRXL flew well for you. Makes it worth it, right? What motor/prop you using?

Heal up quick!
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Old May 03, 2012, 04:01 PM
Planes in flames,,,
jetpackninja's Avatar
Gravity Sucks
Joined Aug 2010
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Yeah man- definitely worth the time to perfect one of the safer launching techniques.
I tangled with a prop myself and it wasn't much fun. 13 stitches and some industrial strength pain killers. It's all good now but I cringe any time I see somebody launch with their hands back by the motor. Heal well.
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Old May 03, 2012, 04:12 PM
McCleary.11's Avatar
United States, OH, Delaware
Joined Mar 2006
757 Posts
Yes, that is blood spatter on the wing! Someone call Dexter!

I am using the 2812-14 Cobra motor with a 10x5 prop on 3s.

Actually my hand was in front. I had just landed a minute before to adjust a camera. Since it was morning, there was dew on the grass which got the wing wet. When I hit the power, my hand slipped a little and allowed it to pivot towards me. While cutting the throttle, my hand must have went to hold the plane up and I got sliced.
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Old May 03, 2012, 04:23 PM
Planes in flames,,,
jetpackninja's Avatar
Gravity Sucks
Joined Aug 2010
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v.1 of the Ninja throttle stick safety.
Rev2 Is on my transmitter now.
I'll try to get some good pictures.
One day maybe I'll start selling these things. I could make millions...
http://www.rcgroups.com/forums/showthread.php?t=1369101
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Old May 03, 2012, 04:27 PM
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United States, OH, Delaware
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I like it! Not sure I could afford one of those fancy gadgets though...
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Old May 03, 2012, 04:30 PM
Planes in flames,,,
jetpackninja's Avatar
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Rev2 cost exponentially more, and still within the Ninja budget
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Old May 03, 2012, 04:41 PM
wheeeeee!
elCapitan's Avatar
United States, UT, Provo
Joined Oct 2011
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Anyone with a Turnigy 9X, go into your settings (for each model) and active the "Throttle Hold" setting. Every time I land, the first thing I do is flip the furthest top left switch, and it doesn't matter if I bump the throttle stick, the motor's not going to turn. Great safety feature.

I also used it once when some kids suddenly ran to try to catch my Albatross as I was landing at a park.

My guess is other tx's have a similar switch setting
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Old May 03, 2012, 05:01 PM
Planes in flames,,,
jetpackninja's Avatar
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BTW one of my favorite things is watching people try to throw their wing into the air and forgetting to turn off their throttle lock
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Old May 03, 2012, 08:15 PM
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ashdec87's Avatar
United States, MI, Detroit
Joined Feb 2004
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Quote:
Originally Posted by McCleary.11 View Post
I have seen the CrashTestHobby video for proper take offs (and apparently didn't learn anything). Can I be the star if the video for incorrect take offs comes out?


5 stitches... Keep your fingers out of the prop! I was lucky it wasn't much much worse.

I have the entire thing recorded with my GoPro! I will post it up later...



On a positive note, I maidened my Reaper XL and it flew Great!
And that's why I use a bungee launcher lol
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