Snao G's

[Rcmaster199 at aol.com]

Well, yes that's true when one is flying IN any specific maneuver such  as 
hover or high alpha circles, for example. BUT, and this is a very big BUT,  
initiation of some 3D maneuvers is quite violent.  
 
Consider a WALL the instant elevator is applied, PARACHUTE under same  
conditions, or BLENDER when controls are  taken to the corners. 
 
I would bet dollars to donuts that a full speed WALL is the most violent of  
these, and it wouldn't surprise me if Earl found somewhere around 25 to 30G  
loads for that maneuver. Rest assured that IF you pattern model survives the  
WALL, (excuse the intended pun) it will survive the rev Ava snap.
 
MattK
 
<In a message dated 1/28/2005 4:17:12 PM Eastern Standard Time,  
mrandmrst at comcast.net writes:

Matt,
I could be wrong, but isn't 3D, by definition, done in a constant state  of 
stall?  Wouldn't that eliminate a lot of the high G's in the  maneuvers?  I 
wouldn't think the airframe would be in as stressed state,  when the flying 
surface is depending on prop wash, not air speed, to do it's  thing.
 
Ken

----- Original Message ----- 
From:  _Rcmaster199 at aol.com_ (mailto:Rcmaster199 at aol.com)  
To: _discussion at nsrca.org_ (mailto:discussion at nsrca.org)  
Sent: Friday, January 28, 2005 1:46  PM
Subject: Re: Snao G's



If this accelerometer is finding 13 G loads generated by a Pattern  model 
snap, a relatively low amount really, I imagine that a 3D model set up  for a 
full array of stunts has to be experiencing double that at  least.
 
Earl could you do any 3D type maneuvers and measurements with the  Yak?
 
Very informative discussion BTW, and may result in improved more  efficient 
building technique, read-- lightest for the desired  strength.
 
thanks
 
matt
 
In a message dated 1/28/2005 1:32:35 PM Eastern Standard Time,  
d.pappas at kodeos.com writes:

That's proof of stall!
If the G loading rises suddenly, and  then holds or droops continuously 
during the roll, then it's probably an  accelerated barrel.
If the profile is sudden rise, sudden  drop to maybe 1/2, then onload, you 
have a real snap.
 
Yia,
    Dean
 
Dean Pappas 
Sr. Design Engineer 
Kodeos Communications 
111 Corporate Blvd. 
South Plainfield, N.J. 07080 
(908) 222-7817 phone 
(908) 222-2392 fax 
d.pappas at kodeos.com  
-----Original Message-----
From:  discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On  
Behalf Of Rcmaster199 at aol.com
Sent: Friday, January 28,  2005 11:45 AM
To: discussion at nsrca.org
Subject: Re:  Snao G's



Good point. Once in the stall, the model should not see the  same continued G 
load. Should drop dramatically. If the  plane doesn't stall to begin with, 
different story.
 
Matt
 
In a message dated 1/28/2005 11:23:25 AM Eastern Standard Time,  
d.pappas at kodeos.com writes:

Let  me add another two cents worth ...
Earl,
What is the sampling rate on your data  logger?
Can  you see if the maximum 13-Gs at 100 MPH was sustained for the  entire 
half second or so that it took to complete the  snap,
or  was it a short spike (like 0.1 second)  and then sustained  at say half 
of that value, for the rest of the  snap.
Of  course, if the data logger samples once a second, we have almost no  way 
of knowing.
 
Later,
         Dean









 
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