[SPAM] Re: Snao G's

[Mike Hester]

I live in the same county, about 15 minutes from the field. The house shook, we thought the air force was doing supersonic manuevers out of Dobbins AFB. Sounded like a sonic boom, with a distinct cracking added. 

Then about an hour later, I get a call: "I'm coming over, you HAVE to see this!"

Next thing I know Cam pulls up in my front yard and drags out a familiar wing with a severe crack about where the wing tube terminates. Ouch.

So it wasn't a sonic boom after all, Cam was just doing 3D =)

-Mike

  ----- Original Message ----- 
  From: Cameron Smith 
  To: discussion at nsrca.org 
  Sent: Friday, January 28, 2005 9:33 PM
  Subject: RE: [SPAM] Re: Snao G's


  You didn't hear it down there?  ;-)

   

  -----Original Message-----
  From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org] On Behalf Of Ron Van Putte
  Sent: Friday, January 28, 2005 8:25 PM
  To: discussion at nsrca.org
  Subject: Re: [SPAM] Re: Snao G's

   


  On Jan 28, 2005, at 7:05 PM, Cameron Smith wrote:

  I look at it more as "Energy Management".   I'm replacing wings on a large gasser from "Poor Energy Management" Dropped it to far with NO throttle & Pulled a Sharp Parachute and the Crack could be heard across the county.


  Cameron - Was it a big county? <BG>

  Ron Van Putte

  ----Original Message-----
  From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org] On Behalf Of Ken Thompson III
  Sent: Friday, January 28, 2005 5:57 PM
  To: discussion at nsrca.org
  Subject: Re: [SPAM] Re: Snao G's

   

  Walls I can see the stress, however I understand that the correct way to enter a wall is at 1/4 throttle or less.  I'm not one of those big ego guys, so correct me if I'm wrong.

  Parachutes are more of a controlled fall, from a partial wall up high, and Blenders begin from a stalled state.  Of course when you slam the throttle to push the plane through the Blender, that could hurt a bunch.

   

  Ken

   

   

   

  ----- Original Message -----

  From: Ed Alt 

  To: discussion at nsrca.org 

  Sent: Friday, January 28, 2005 5:05 PM

  Subject: [SPAM] Re: Snao G's

   

  Yep, but the transition into it can be stressful.  Stuff like Walls, Parachutes, Blenders, certain brands of Waterfalls put mucho strain in the airframe. 

  Ed

  ----- Original Message -----

  From: Ken Thompson III 

  To: discussion at nsrca.org 

  Sent: Friday, January 28, 2005 4:16 PM

  Subject: Re: Snao G's

   

  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 

  To: 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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