[pianotech] MOE for sugar pine versus sitka spruce

[Encore Pianos]

Elvis has left the building!  Chaos has resulted, at least in the Midwest,
and it is spreading rapidly!

I knew it had likely been posted in the past, but spending anything less
than a week searching through the archives for a subject is considered a
successful search.  

I didn't get your handout for your class.  I was otherwise occupied,  out
greasing the skids so that you guys could have all the fun creating  new
little R, C, & S monsters  :-)

Will
(hiding somewhere with the Wisconsin Democratic lawmakers)

Thanks, Ron



-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Thursday, February 24, 2011 2:29 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] MOE for sugar pine versus sitka spruce

On 2/24/2011 12:33 PM, Encore Pianos wrote:
> Thank you for that info.    I have had others do these calculations for me
> in the past for rib dimensions, and do not have this  formula.   I would
> love to do this calculation myself.  Is it possible to ask for this 
> beam deflection formula?

No, absolutely not. It's expressly (that's Elvis Expressly, recently sighted
in Fargo) forbidden to divulge this:


Deflection formula for center loaded beams, where L=length, H=height, 
W=width, B=bearing load, and E=modulus of elasticity of the material in 
PSI. All dimensions in millimeters. Typical E value for Sitka Spruce is 
about 1,570,000 PSI.

With load in pounds: Deflection in mm=(L^3*B)/(E*0.0062*W*H^3)
With load in kilos: Deflection in mm=(L^3*B)/(E*0.00281227*W*H^3)

If this were to be common knowledge, chaos could result.

Hint: It's been posted to pianotech a dozen times or more in years past, 
and it's on the last page of the handout you got at my all day belly 
class. It's just the standard flexure formula for center loaded beams.
Ron N, not recently sighted