[SPAM] Re: [SPAM] Re: Displacement during snap rolls (was Why is it so quiet?)

Ed Alt Ed_Alt at hotmail.com
Wed Dec 29 06:16:17 AKST 2004


Agreed - the 40% Scale Aerobats are actually fairly lightly loaded and they're generally moving forward slower as well.  Being a little less ballistic during the snap probably makes up for some of the differences observed.

Ed
  ----- Original Message ----- 
  From: Del Rykert 
  To: discussion at nsrca.org 
  Sent: Wednesday, December 29, 2004 10:10 AM
  Subject: Re: [SPAM] Re: Displacement during snap rolls (was Why is it so quiet?)


  More mass and heavier wing loading will keep the aircraft more on same track, whether full scale or model.

      del

    ----- Original Message ----- 
    From: Ed Alt 
    To: discussion at nsrca.org 
    Sent: Wednesday, December 29, 2004 10:01 AM
    Subject: [SPAM] Re: Displacement during snap rolls (was Why is it so quiet?)


    Randy:
    You might not be seeing an offset using a snap switch because all of the controls start moving at once.  The initial roll isn't an autorotation when using a snap button, although it might eventually wind up being a snap roll sometime during the roll.  Watch a full scale aerobat do a snap and you will see a distinct pitch change preceding any rotation.  It shouldn't be any different with a model - you want to lead, even if only slightly, with elevator, then rudder, then aileron.  If you develop sort-of a timed stirring motion to put the controls in and take them out, it seems to work the best.  Also, if you "fly it" through the snap instead of using a snap switch, you can much more easily control the energy that is used up.  Anyway, I've noticed that there generally isn't much displacement from the snap with these 2M pattern birds.  It's much less than what I'm used to with the big gas stuff, but it's still there.

    Ed
      ----- Original Message ----- 
      From: Randy 
      To: discussion at nsrca.org 
      Sent: Wednesday, December 29, 2004 9:30 AM
      Subject: Re: Displacement during snap rolls (was Why is it so quiet?)


      As I am trying to learn advanced I should expect to see a track offset during the two snaps?  I do not remember seeing an offset when I used the snap switch instead of moving the stick myself.

      So what wold be the normal order of stick movement for a snap on a Focus2?  Seems to me that different designs might need controls to do a snap cleanly.

      Randy
        ----- Original Message ----- 
        From: John Ferrell 
        To: discussion at nsrca.org 
        Sent: Wednesday, December 29, 2004 9:19 AM
        Subject: Re: Displacement during snap rolls (was Why is it so quiet?)


        As near as I can tell Somenzini's secret is in the setup, not the snap itself. 
        The only place I see to downgrade for offset is in presentation.

        I admit to being one of his fans.

        I think the question is a very good one!

        John Ferrell    
        http://DixieNC.US

          ----- Original Message ----- 
          From: Bob Pastorello 
          To: discussion at nsrca.org 
          Sent: Wednesday, December 29, 2004 6:47 AM
          Subject: Re: Displacement during snap rolls (was Why is it so quiet?)


          Good points, David, but my question is based on a LATERAL, and "Parallel" shift in the track.  Assume that I get 'lucky', and nail the line before the snap, definitively BREAK during the snap, nail the exit on the original heading/track, but shifted sideward maybe 3 feet.
              My experience is that a properly-executed snap manuever - anyplace - MUST translate some forward momentum into angular sideward momentum, thus shifting the track of the manuever.
              If this is a "downgrade", where is the criteria, how much are the downgrades, and since we're not talking about an "angular" offset, the point per 10 or 15 degree deviation rule doesn't seem to fit.
              In fact, I would argue (and I'm confident there are aerodynamicists out here who could calculate and prove it so) that NO appropriately-executed snap manuever CAN occur without offset of the original track.

              If someone does the imitation/fake "snap roll" ( the rapid, low-rudder, high-aileron, semi-stall ROLL) there ISN'T an offset, usually.  At least in the fake ones I judged LAST season.

          Bob Pastorello
          NSRCA 199  AMA 46373
          rcaerobob at cox.net
          www.rcaerobats.net
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