Re: Re: Determining balsa stiffness

From: <RLBailey_at_care4free.net>
Date: Mon, 16 Jan 2006 12:38:18 -0000

I always cut up anything other than C grain wood into strips up to 1/2" wide
and test each individually to find the good bits. I use the Euler deflection
method in which the buckling load is measured, to calculate the Young's
modulus for stifness. You will often find
considerable variation between strips from the same sheet. I write the
numbers on each strip so that I know the relevant values ie density and
Young's modulus. That is then noted for the model build. This is probably
more important for 35 cm than any other class. The biggest problem then is
finding the best C grain for stick and boom.

Bob

Then when u----- Original Message -----
From: "Don Slusarczyk" <don5490_at_sbcglobal.net>
To: <Indoor_Construction_at_yahoogroups.com>
Sent: Saturday, January 14, 2006 1:48 AM
Subject: Re: [Indoor_Construction] Re: Determining balsa stiffness


>I always cut the 36" long sheets to 18" long then cut them 1" wide. In
> essence 1" x 18" strips then tested them. If the sheet is thin enough,
> hold it up to the light first and don't test where dark streaks are
> located, they will mess up your numbers big time!
>
> Don.
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Received on Mon Jan 16 2006 - 05:39:45 CET