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<DIV>Wayne, </DIV>
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<DIV>Oh yeah babe, isn't that a kick? A 10 year old being introduced to the fine art of balsa structure and mechanical engineering design. Fabulous!!</DIV>
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<DIV>Give that teacher a bonus. </DIV>
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<DIV>Digressing a bit from the Balsa theme, Warren trusses, IF I remember right, are basis for airliner spars among other things. Several years ago, as a key supplier to Boeing, we had opportunity to witness the triple 7 spar test where the wing was folded to determine g-loading capability. Impressive test. </DIV>
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<DIV>Matt</DIV> <BR>-----Original Message-----<BR>From: Wayne Galligan <wgalligan@goodsonacura.com><BR>To: NSRCA Mailing List <nsrca-discussion@lists.nsrca.org><BR>Sent: Wed, 29 Mar 2006 08:35:57 -0600<BR>Subject: Re: [NSRCA-discussion] An education in balsa usage for pattern<BR><BR>
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<DIV><FONT face=Arial size=2>Matt,</FONT></DIV>
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<DIV><FONT face=Arial size=2>My son did his 5th grade science project using balsa construction. His project was to determine what bridge truss design held the most weight for a given span. It was truly amazing how much weight the structure would hold. The spans he built where 7"x7"x24" and weighted 1.5 oz, made of 1/4" square med grade balsa glued together with thin c/a. The Warren truss held 42 lbs before collapsing and the two other structures were close behind holding 32 to 38 lbs. It was a learning experience for both of us. It gave me a better understanding of how certain truss structure builds stiffness, strength and be light weight. </FONT></DIV>
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<DIV><FONT face=Arial size=2>Wayne Galligan</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B> <A title=rcmaster199@aol.com href="javascript:parent.ComposeTo('rcmaster199@aol.com');">rcmaster199@aol.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=nsrca-discussion@lists.nsrca.org href="javascript:parent.ComposeTo('nsrca-discussion@lists.nsrca.org');">nsrca-discussion@lists.nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, March 28, 2006 6:58 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] An education in balsa usage for pattern</DIV>
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<DIV>Balsa is pretty amazing stuff overall, particularly for a natural material. The Xylem that makes up much of the superstructure of any wood (that's what we commonly hear as grain), is essentially a huge number of tubes arrayed side by side, but interconnected along the length. The tubes serve a terrific function in the long direction and the interconnects make the structure have reasonable transverse strength as well. </DIV>
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<DIV>The closest thing manmade that will surpass it in terms of mechanical strength vs flex vs weight vs cost will likely be Buckytube if you excluded the cost. That's just in laboratories now, being made in very small quantities supporting very high end applications. This stuff is the true unobtainium that some have complained about. But that's another subject.</DIV>
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<DIV>There used to be an annual competition in colleges where a very small, known quantity of balsa and glue were used creatively by students to build some kind of support structure like a small bridge. These things would hold unbelievable amounts of weight. </DIV>
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<DIV>Alas, the weakness is shock loading. </DIV>
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<DIV>Matt</DIV> <BR>-----Original Message-----<BR>From: Adam Glatt <adam.g@sasktel.net><BR>To: NSRCA Mailing List <nsrca-discussion@lists.nsrca.org><BR>Sent: Tue, 28 Mar 2006 16:44:02 -0600<BR>Subject: Re: [NSRCA-discussion] An education in balsa usage for pattern<BR><BR>
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<DIV class=AOLPlainTextBody id=AOLMsgPart_0_a3a3b4df-d994-412a-a29e-2c471d7b45f7><PRE><TT>Not directly applicable to pattern, but certainly a good start:
Buy and build a Stevens Aeromodel kit. The planes are small (35-50"
span, 1-2.5lbs) and electric powered. I'm about 1/2 done building the
Edge 540, and am actually enjoying the build because I am constantly in
awe of the genius wood design and its results (consider that this Edge
540 is 40-sized, but will weigh only 2lbs with more performance than all
but the most dedicated 40-sized 3D glow planes).
-Adam
White, Chris wrote:
>
> Can anyone tell me where a person can get a "Crash" course in learning
> about balsa weights and strength and its proper use in balsa pattern
> models.
>
> I notice a few years ago that in the 99 world champs most of the
> Japanese pilots models were balsa and light weight too. It seems that
> everything I read of late seems to indicate that light weight and
> strength only come with composite construction.
>
> Thanks..Chris
>
> ------------------------------------------------------------------------
>
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