Predicted Panel Thickness

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RonRapp
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Predicted Panel Thickness

Post by RonRapp » Sat Aug 12, 2017 12:55 am

I am having problems with either the shear modulus equation 4.5-4 or the thickness equation 4.5-7 when entering them into Excel...I have rechecked the equations multiple times, but my targeted panel thickness does not match those shown in Table 4.5-3...

Has there been any "oh yeah" moments from anyone else?

Thanks
Ron Rapp
Littleton, Colorado

RonRapp
Wandoo
Posts: 14
Joined: Wed May 03, 2017 12:11 am

Re: Predicted Panel Thickness

Post by RonRapp » Sat Aug 12, 2017 1:56 am

The shear modulus calculation is correct in my Excel equation, but I still have issues with the thickness equation 4.5-7...I am using the a=.49m and b=.195m (half panel) box size that Trevor is using in Table 4.5-3, but the result shows 0.00894m thickness...???

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Trevor Gore
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Re: Predicted Panel Thickness

Post by Trevor Gore » Sat Aug 12, 2017 8:32 am

Hello Ron,

Have you checked out this thread and this thread?

The minor accuracy issues discussed in those thread have been cleared up in the 2nd edition, so it just comes down to coding errors (mostly "zero count" problems) and Excel's inherent susceptibility to ill-conditioning, which can be circumvented as discussed in those threads.

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kiwigeo
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Re: Predicted Panel Thickness

Post by kiwigeo » Sat Aug 12, 2017 11:52 am

Also check your units Ron.
Martin

RonRapp
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Re: Predicted Panel Thickness

Post by RonRapp » Sun Aug 13, 2017 8:00 am

Thank YOU!
The threads really helped...still not sure why the problem...must have been the Excel issue...Thanks again, Ron

RonRapp
Wandoo
Posts: 14
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Re: Predicted Panel Thickness

Post by RonRapp » Fri Nov 30, 2018 10:45 am

I wanted to post an update on the finished guitar...Ron
BTW, I am very happy with the final sound!
Thank you Trevor for introducing me to this style of building.
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Trevor Gore
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Re: Predicted Panel Thickness

Post by Trevor Gore » Mon Dec 03, 2018 7:35 pm

RonRapp wrote:
Fri Nov 30, 2018 10:45 am
BTW, I am very happy with the final sound!
Ah, there's the answer to my question in another thread!

Excellent!

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kiwigeo
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Re: Predicted Panel Thickness

Post by kiwigeo » Mon Dec 03, 2018 7:54 pm

Excel can be a challenge. One year on and Im still trying to get a spreadsheet up and running to model nut and saddle compensation. I think Excel is like me when confronted with numbers to a large number of decimal places....it shits it'self :(
RonRapp wrote:
Sun Aug 13, 2017 8:00 am
Thank YOU!
The threads really helped...still not sure why the problem...must have been the Excel issue...Thanks again, Ron
Martin

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