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Offline Earle Andrews  
#31 Posted : Sunday, December 3, 2017 2:29:05 PM(UTC)
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The rotational speed of the snap roll is NOT a judging criteria, nor should it be in my opinion. Some planes snap roll faster that others (high wing loading vs low) and of course pilot input as far as "unloading the wing" via reduction of elevator input during the snap, can make huge differences in snap roll rotation speeds.

Provided there is A - Pitch departure and B - Autorotation.....then it is a snap roll.

Yes, it would be wonderful if our planes had the wing loading, mass and rotational inertia that full scale has.....then our snaps would all look very similar. I have zeroed some national level unlimited competitors due to lack of pitch departure during a snap. That is a criteria that can be seen and judged accordingly. If we (IMAC) start delving into rotational speeds then we are in serious trouble on the judging line!
Offline Bill Teeter  
#32 Posted : Sunday, December 3, 2017 2:47:20 PM(UTC)
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If you are referring to something I said then I am in full agreement that speed is not a judging criteria. No issue there. I am just saying that some of these I have seen are so fast I don't think the connection between my eyes and my brain is able to sort out if I saw pitch and autorotation or not. In an Unlimited sequence there is so much going on that it is sometimes hard to make the determination, especially with rolling elements in opposite directions. Benefit of doubt ......
Offline Earle Andrews  
#33 Posted : Sunday, December 3, 2017 3:12:15 PM(UTC)
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No Bill.....not with anything you said. My comments are regarding the "Blip Snap" thing.
Offline Bill Teeter  
#34 Posted : Sunday, December 3, 2017 4:34:53 PM(UTC)
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Thanks Earle. Some days instant replay would be useful. Fun to see the slow motion in the video. But I hope we don't have to go there.
Offline Steven Brentson  
#35 Posted : Sunday, December 3, 2017 7:51:39 PM(UTC)
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"As always, the pilot is given the benefit of the doubt..." It's in the rules a lot.

Offline Bill Teeter  
#36 Posted : Sunday, December 3, 2017 8:46:57 PM(UTC)
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Originally Posted by: Steven Brentson Go to Quoted Post
"As always, the pilot is given the benefit of the doubt..." It's in the rules a lot.



In the case of snaps, yes if there is visible pitch and autorotation - if not visible then should be zeroed
Offline Extra Yak  
#37 Posted : Sunday, December 3, 2017 9:11:39 PM(UTC)
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With regard to the original question concerning how to do the positive snap from inverted without making it look ugly. I think I am changing my mind on my previous comment given this excellent discussion and video. I suggested not getting too deep in that particular snap. However, due to perspective resulting from looking at the plane from below facing the canopy, it will not be as easy to identify a small pitch departure compared to looking at the plane from its side. So in the effort to make the snap look better by inducing a smaller pitch departure, a pilot would run the risk of zeroing that maneuver. Better to do an ugly snap and score than one that looks pretty but is zeroed.

Edited by user Monday, December 4, 2017 3:15:29 AM(UTC)  | Reason: Not specified

thanks 3 users thanked Extra Yak for this useful post.
Orthobird on 12/3/2017(UTC), Dangerous Dan on 12/4/2017(UTC), Vicente Bortone on 12/6/2017(UTC)
Offline Adi Kochav  
#38 Posted : Thursday, December 7, 2017 1:34:53 AM(UTC)
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Hi friends.

Here is a corrected video.
In particularly regarding the blimp snap.
Like the criteria it’s either you see a snap or not.
Thank you Manrico for all the great info and the hard work in making imac accessible to everyone.

Cheers
Adi

https://m.youtube.com/watch?v=DhP9RaFK-lI
Offline Brad  
#39 Posted : Thursday, December 7, 2017 6:58:24 AM(UTC)
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Thanks for the correction about the Blip Snaps. I do caution everyone about calling something a "Barrel Snap" and zeroing it. I watched the video many times, slowed it down, stopped it, etc. during the barrel snap discussion, and personally, in each of the cases, I saw a snap where departure and autorotation started simultaneously, which is perfectly OK. I think what Manrico is trying to demonstrate is the "cross controlled" snap, where the wrong rudder is input. In that case, the rudder is fighting the autorotation, causing the plane to fly a spiral path, rather than autorotation. In the video, what I'm seeing is just a slower snap. The rotational speed of a snap will be determined by the difference in lift created between the wings by the stall. I looked as closely as I could at the snaps labeled "barrel snaps" and the rudder and aileron inputs by the pilot were correct. This highlights why the judges must give the competitor the benefit of the doubt. It is possible for the pilot to input rudder and ailerons before hitting the elevator, in which case the rotation may start before the pitch departure. Any rotation/roll observed prior to the required pitch movement is to be downgraded 0 .5 points for each 5 degrees of such rotation.

Brad
Offline Kevin Wilson  
#40 Posted : Thursday, December 7, 2017 11:20:37 AM(UTC)
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It is hard to tell in the video, but my interpretation of the barrel snap is where autorotation never occurs and the plane just flies the path as in a barrel roll. Inputs are the same, just slow enough where there is no autorotation, and that indeed by definition is a zero.
Offline Krzy4rc  
#41 Posted : Thursday, December 7, 2017 11:27:28 AM(UTC)
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Any opinions on the upline vertical snaps shown at 14:00?

Because of the power beinig applied, the plane appears to autorotate around the prop, but the pitch departure of the nose doesn't seem to happen, though the pitch of the airplane does change (just seems to be pivoting at the nose).

I have seen this before, is it an optical illusion? Do you think there was a pitch departure?

Just curious. To date I have scored the snaps.
Rich
Krzy4RC
SC-ARD (Louisiana)
Team Jeti
Hybrid Pilot/Troublemaker
Offline Kevin Wilson  
#42 Posted : Thursday, December 7, 2017 11:34:05 AM(UTC)
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I thought there was pitch departure in those upline snaps, but videos can be deceiving, especially when there are no clouds as a background.
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