The perfect Snap, El Snap perfecto??

[Kiwi]

Ok,

Everywhere I go some one has a different definition of what a simple snap roll consists of and how you do it. I know in a full scale there is NO AILERON involved but if you snap a 40% on elevator and rudder only you end up so deep into it that basically you come to a stop.

So lets open up the debate here on what the judges are really looking for and what the pilots perspective is on what he needs to accomplish to match that judges expectations.

OK

En todos lados existe un definicion diferente en que consiste un SNAP ROLL y como hace lo. En escala real yo intiendo que no existe el aileron en un Snap. Es solo elevator y timon pero con un modelo si si haces un snap con puro elevator y timon el snap es muy profundo y casi si parar el avion.

Entonces por favor entre nosotros vamos a participar en un forum para ver que quiere los juezes y desde el perspectivo de los pilotos como cumplir este maniobra en un forma que ganar los ideals esperado del juez.

[krayzc]

i hear its different set up per bird but for me its 25-30 degrees of ailerons, 7-15 degrees of rudder, and about 4-8 degrees of elevator throw. some received a quick input of the elevator and then off of those to the rudder and ailerons.

[Vic3D]

Cada persona tiene su forma diferente de hacerlos, y cada cual tiene sus ajustes personales para sus aviones. Lo mas importante en el snap es que se salgan de la linea de vuelo. A esto se le llama "departure" y que el avion autorote con un ala en "stall" y regrese a la misma linea de vuelo. Por eso es que siempre se le da un "bump" al elevador primero. Mientras se cumplan estos criterios, lo demas es cuestion de gustos del piloto.

[Kiwi]

Vic, you are correct but a Snap is a fully stalled manoeuvre and technically has no aileron input into it at all. In full scale thats a 100% fact.

But in Scale Aerobatics the use of aileron is almost considered a must use input.

Let me explain my question some more here.

I see almost all mode 2 pilots slam the right stick in the corner depending on the desired snap direction. My call on that is it is more a roll than a snap. The aircraft must break the line of flight by X degrees (what is X) prior to the departure into the autorotation. An autorotation is not dependent on aileron at all.

So if the tail breaks and the roll starts at exactly the same time is it a roll or is it a snap.??

[Mithrandir]

I Cheat.... On an upline for example... in low rates... I apply Full Up elevator and you can see the plane start out a pure pitch for just a nano-second... then I apply aileron and rudder whilst simultaneously going to neutral elevator. If I hold the elevator, it gets way too deep.... and my low rates are prolly IMAC'ish Really Really high rates.

[3dAndrew]

Someone please get Snap a Saurus on here! This thread is useless without his advice. Thats why he's "SNAP A SAURUS" LOL
Andrew

[Vic3D]

	Quote: Originally Posted by Mithrandir
	I Cheat.... On an upline for example... in low rates... I apply Full Up elevator and you can see the plane start out a pure pitch for just a nano-second... then I apply aileron and rudder whilst simultaneously going to neutral elevator. If I hold the elevator, it gets way too deep.... and my low rates are prolly IMAC'ish Really Really high rates.

That's not cheating though. You already departed your line of flight.

[Mithrandir]

I think in this video there is a double inside snap on a vertical line that looks pretty good....
I used the "Cheat" method described above!! lol

http://media.putfile.com/FUTABA-14MZ...0-FUNTANA-140S

[snap a saurus]

I'm here, obviously the subject is THE PERFECT SNAP.
Here is my perfect snap definition, apply full power with a little up elevator, once the plane breaks ground few inches apply full up, full rudder and full aileron and yell SNAP A SAURUS BADASS, now that's a perfect snap, kids don't try this at an IMAC competition because it will get you a Zero.

[krayzc]

lol i love it !

[bodywerks]

Snaps suck!!!
Bottom line, there is no right way to snap. I have seen the pros change up the way they snap based on who's judging. At one TAS, judges were so insistant on seeing a pitch break that pilots were pitching, waiting what seemed to be a full second, and then rotating, and of course they used ailerons.
I really think there is something the pros are doing that some of us might not know about, because I input my elevator first and hard and have what I thought was a lot of elevator (12 degrees), but it still doesn't break like I'd like it to.
Interestingly, I talked to both Sean McMurtry and Jason Noll about throws, since we all fly the same plane, and they were talking about 20+ degrees of elevator and rudder and as much as 40 degrees of aileron!!! And I thought my 35 degrees of aileron was too much??

[Andy Thomas]

The snaps are getting alot deeper than what we saw a couple of years ago.

[JLeyland]

Full scale precision aerobatic pilots use alot of aileron for thier snaps also. You'd be hard pressed to do a precision snap in any airplane full scale or model without aileron. Here's a good vid showing aileron input in an Extra.

YouTube - Snap Roll - Extra 300

[BrunoMacedo]

Hey Kiwi !! You asked the most polemic question of all !

Here is my point of view about the snaps :

First, ok scale aerobatics is all about reproduce the full scale aerobatics with models. That's one of the things that the red book states. But what we have to see is that "similarity" is more concerned to the geometry and the figure of the manuever rather than the control surfaces input. You're right about the full scale, they don't use ailerons to start the rotation, just in some cases they use opposite aileron to stop the snap. In full scale snap is a true autoration, you bump the elevator to get critical angle of attack an apply the rudder in the direction of rotation you want (for positive ones), this makes the inner wing to get slower airspeed, so it stalls and the rotation begins.

In models there is no way to this happen. In a simple way just because our wing loads are much lower than the full scale ones. You can bump the elevator apply rudder but the wing doesn't stalls completely and we fall in that barrel deep snap like you said. So, to "simulate" a wing stall we have to apply massive amount of aileron, to make the model snap looks similar to the full scale one.

Well, the red book is quite objective in judging a snap, altought is a very tough thing to see everything that is wrote there. Snaps must have pitch, in the correct direction, and autorotation. Remember pitch is the depart of the nose of the airplane from the flight path. The pitch can come first or simultaneous with the rotation. Autorotation is a stalled wing movement where the nose and tail are off the flight path.

My personal opinion, please someone correct me if I'm wrong : but once you have autorotation you have pitch too. What happens if you try to start an autoration without pitch is that you started aileroning on the snap, so its 0,5 point per 5 degrees of aileron prior to the autorotation.To pitch before the rotation is a tough thing but minimizes the chance to get a zero on that snap for not pitching. You can see some top guys always pitching before the rotation in most snaps but there are some kind of snaps that they don't pitch before, specially the negative snap on positive lines or vice-versa.
So both ways can be good.

Bruno

[JLeyland]

Precision full scale snaps require aileron.