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Feb 11, 2020, 09:12 PM
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Cowbrakes


Hello, could someone educate me about the use of cowbrake in rc planes? Thank you.
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Feb 11, 2020, 09:26 PM
AndyKunz's Avatar
Crow braking is when the ailerons move up together and the flaps move down.

By moving the ailerons up, it is also reducing the angle of attack, which reduces the likelihood of a stall. The flaps moving down, by contrast, are increasing their angle of attack and giving lots of drag.

Basically, you use the flap deployment to increase drag and slow down the plane, and the ailerons to keep from stalling and spinning in.

Andy
Feb 11, 2020, 09:27 PM
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scirocco's Avatar
My first image was landing in a cow pat, which pulls the model up fast but makes a big mess.

But I think you might mean crow braking.

Also known as butterfly and commonly but not exclusively used on gliders, crow involves simultaneously deflecting ailerons upward and flaps downward to achieve increased drag and reduced lift on the outboard part of the wing. In gliders, often controlled by the throttle stick for precise glideslope management when landing.
Feb 11, 2020, 09:29 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by Aurelio Arenas
Hello, could someone educate me about the use of cowbrake in rc planes? Thank you.
Are you asking about crow braking ? Usually used with gliders ?
Here is the result for a Google search for crow braking :

Crow braking: also called 'Butterfly braking', this rc glider wing function is used when landing. When Crow is activated the flaps drop down and both ailerons deflect upwards, all at the same time.
Feb 11, 2020, 09:42 PM
Registered User
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Sorry about the misspelling. With crow brake I have no banking I guess. How do you set up crow brake? Thank you.
Feb 11, 2020, 09:51 PM
AndyKunz's Avatar
You can still bank. They don't get deflected all the way, just some. And you still have differences.

Andy
Feb 11, 2020, 09:58 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by Aurelio Arenas
How do you set up crow brake? Thank you.
That may depend on your transmitter , take a look in your transmitter manual .

For whatever plane you plan to use crow braking , be careful of stalling ..... especially low to the ground .
Feb 11, 2020, 11:06 PM
homo ludens modellisticus
Ron van Sommeren's Avatar
More about butterfly/crowbrake.

Vriendelijke groeten Ron
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Feb 12, 2020, 10:49 AM
aka: A.Roger Wilfong
gnofliwr's Avatar
As long as you don't run out of servo travel, you still have roll control.

I have a Mini Ultra Stick with a 4 servo wing setup that I used to fly in funflys. The MUS wing came with full strip ailerons, but was built with 4 servo pockets and a split point in the surface framing to cut the ailerons and flaps apart. In normal operation, the flaps and ailerons work in unison as a single control. Flip a switch and the flaps get a down offset and the ailerons up. They both still have enough travel to not hit the travel limits so with enough power to over come the extra drag, you can still do rolls and stuff.

The real advantage was in some funfly events where a longer landing time lowered your score. With crow deployed, I could point the nose straight down, chop the throttle, and the plane barely picked up any speed in the dive - a few feet off the ground, I could level out and add throttle to control the crash, ER, landing, yeah, landing .

With sailplanes, crow can really help in getting out of a "hat sucking" thermal, or hitting the spot for max landing points.

- Roger
Feb 12, 2020, 12:53 PM
CR5
CR5
Registered User
As gnofliwr mentions, your plane must have a servo on each surface, one for each aileron is a must.
My 40 size UltraStick is set up with CROW.
I currently have my Timber-X set up with full span ailerons through the mixing in the radio but can not go with CROW as well because all the receiver servo outputs are full, so my ailerons are on a Y-harness while my flaps have their own channels. I don't feel like taking the AS3X receiver out of it just to have another switch to play with. It flies slow enough with the flaps at full deflection.

If you're new to flying I wouldn't worry about this kind of stuff though, it isn't needed and won't make your plane fly better or easier. Concentrate on the basics and move to this kinda playing when you get bored with your plane. Or as gnofliwr mentioned, when you are competing in a short landing competition or something where it will allow you to slow it way down. Just remember, it still needs to be moving fast enough for the wing to generate lift of it will fall from the sky. Practice high and bring it down as you get comfortable with what the plane is going to do.

Good luck
Feb 13, 2020, 10:27 AM
Damage is expected
Crow brakes are especially helpful on gliders with thin, efficient wings. It helps reduce airspeed and increase the rate of sink on landing. Very helpful when landing a $1,600 sailplane while slope soaring.
Feb 13, 2020, 03:49 PM
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Lynxman's Avatar
Even if you max out the servos you still have control, because the outboard aileron servo will move down. I have yet to experience lack of control, even though I can set my servos to near max travel. I have crow on a dial. It's amazing how much slower my glider flies with crow. Landing it without crow is very hard on our field.

Cows are good for stopping too.
Feb 13, 2020, 04:04 PM
CR5
CR5
Registered User
Quote:
Originally Posted by Lynxman
Even if you max out the servos you still have control, because the outboard aileron servo will move down. I have yet to experience lack of control, even though I can set my servos to near max travel. I have crow on a dial. It's amazing how much slower my glider flies with crow. Landing it without crow is very hard on our field.

Cows are good for stopping too.
And tasty
Feb 13, 2020, 04:46 PM
Registered User
speed2004's Avatar
I prefer cowbell braking. Makes more noise....
Last edited by speed2004; Feb 13, 2020 at 08:54 PM.
Feb 13, 2020, 05:51 PM
homo ludens modellisticus
Ron van Sommeren's Avatar
To change the title click edit, followed by click on advanced edit.
That will teach them


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Without a watt-meter you are in the dark ... until something starts to glow
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