Twisting deflection

[KreherGuitars]

I have a set of irregular shaped plates. And for calculating the thickness I'm going to get the Young's with deflection rather than tapping for the frequencies. I have read the materials here on how to go about it and it seems easy enough except the twisting deflection. I saw someone secure three corners then deflect the 4th corner. Is that the method of choice?

[kiwigeo]

Have you see this thread? viewtopic.php?f=33&t=8716

[KreherGuitars]

Yes I have read that thread. And this one viewtopic.php?f=33&t=8707

And they are helpful. Just looking for more direction on the G_LC using deflection. Seems like most guys just use an average value for the wood species

[Andos]

The calcs shown in the book are for beam deflections where the length is substansually longer than the width. Deflecting the front panel by the corners doesn't give you the correct profile to use. You'll need to cut a strip off that is on the angle you want to check.

Dissclaimer:
I have never used the deflection method so I can't vouch for the results. It may pay to do some trial runs on some scrap pieces first.
Do let us know outcome, though. I have a similar top set coming up soon!!