Re: Const. question from Phil Alvirez

From: Bill Gowen <b.gowen_at_earthlink.net>
Date: Thu, 10 Aug 2006 17:50:54 -0400

Phil, Mark, whoever
I've got some numbers for F1L parts on www.indoornews.com in the F1L build article. I'm not sure these are what you really want since I have a lot of wood on hand and was looking for the best I could find. Most of the parts would function okay with lower numbers. Anyway it would be something to compare to.
Bill Gowen
Decatur, GA USA

  ----- Original Message -----
  From: Mark
  To: Indoor_Construction_at_yahoogroups.com
  Sent: Thursday, August 10, 2006 2:21 PM
  Subject: [Indoor_Construction] Const. question from Phil Alvirez


  Subject: Stiffness tests for balsa.
  Anybody : Do you have, (or know where to get), stiffness tests for
  all
  parts (with figures) for the light weight categories such as F1d,
  Intermediate Stick, Limited and regular Pennyplanes, Mini-Sticks, and
  the
  like?
  I mean, something like what Larry Coslick did on that article
  published
  (twice) in the INAV about E C B (notice that I don't say "Easy B"-
  it's
  simple, very few pieces, but a hell to build and fly) in which he
  provides
  the modeler with an easy way to test every single piece before
  building
  the
  model , so there are no surprises after finishing it. That could be
  helpful
  to bring new people into this dying hobby of ours.
  With balsa wood getting more scarce every day (ARF's are the way most
  guys
  fly nowadays), how do you expect anybody finding the way to build to
  weight-or build light-if he doesn't have points of comparison? And
  it's
  frustrating to build just to learn that all the effort was for
  nothing,
  even
  if you build to weight, as the plane is too flexible. I can tell you
  from
  my own experience!
  Besides Larry's data, the only other time I have seen anybody telling
  you
  how to test something for stiffness on a practical way (with
  figures)
  is
  what Doug McLean mentioned in his article about a bipe Penny,
  published
  in
  the Model Builder (Sept 76 issue) for the selection of the wing spars
  (as a
  coincidence, it was in the same issue that an article about a
  control-line
  plane designed by yours truly appeared-in those days I was into that,
  but
  not yet into indoor). McLean tells us precisely what to seek: For a
  given
  spar size, let the spar protrude 4-1/2", hang a weight of 2 grams
  from
  the
  tip, and the deflection shouldn't be more than 3/8". That's what we
  need to
  know!
  So, please, tell us if you have figures like those.
  Regards
  Phil Alvirez



   

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Received on Thu Aug 10 2006 - 14:51:45 CEST