Re: Wing Post Sockets (tubes)

From: <RLBailey_at_care4free.net>
Date: Mon, 26 Feb 2007 11:36:03 -0000

I suggest my approach with F1D's and F1L's which have the same problem. Attach thin slivers of thin balsa (up to 10 thou) or if not possible, strips of tissue, using Ambroid or similar; these bulk up the posts where needed. Cyano sets too hard and adjustment for a good fit is very difficult to get right. I haven't tried talc and cyano.

As regards trim setting, I ensure that the posts can go right through the sockets and when I believe the trim is correct, I cut off the posts flush with the far end of the socket. Next time out, assemble with posts flush with the sockets. Marks are OK if you only need one on each post, but you'll be lucky if you do!

Bob
----- Original Message -----
  From: calgoddard
  To: Indoor_Construction_at_yahoogroups.com
  Sent: Sunday, February 25, 2007 1:50 AM
  Subject: [Indoor_Construction] Wing Post Sockets (tubes)


  Our Science Olympiad team has a plane that is right at the minimum
  weight and is well trimmed. An excellent prop/motor combination has
  been found through many flights.

  The lower rounded portions of the wing posts have apparently shrunk
  or compacted slightly over time and are starting to get looser in the
  wing sockets than the kids would like. They are made from 1/16 square
  balsa. The students don't want any unexpected, unintended changes in
  the angle of incidence of the main wing during a flight if, for
  example, the plane collides with a beam. The students would rather
  not replace the wing posts and risk damaging the wing. Unfortunately
  the wing posts and their angles braces were glued to the LE and
  trailing edge spars with CA. The students don't want to have to
  change the wing post sockets on the MS for fear of damaging the motor
  stick.

  I suppose you could cut off the lower segments of the existing
  wingposts and glue new segments over the same, with slightly larger
  rounded portions, but the new lower segments would have to be
  perfectly aligned to maintain the proper wash in on the inboard
  traing edge.

  Is there a good way of adding some material to the rounded lower ends
  of the wing posts to so that they fit more snugly in the wing post
  sockets? Someone mentioned putting a layer of CA on them. But then
  you can't do the temporary fix of wetting them so they expand.

  For wing post sockets our team is using Post-it tabs rolled around
  drill bits and held together with Duco, as recommended in Lew
  Gitlow's book. They have found them to be much better wing post
  sockets than those rolled from Japanese tissue which get mushy and
  the plastic tubes which are difficult to securely glue to the motor
  stick. They only weigh about .02 grams each.

  Thanks for your recommendations.




   

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Received on Mon Feb 26 2007 - 03:44:01 CET