Unusual Panal Size

[AKEric]

A few years ago--pre The Books--I purchased the attached four piece book-matched set of Honduras Rosewood with the intent of making two guitars out of it. As you can see, I will not be able to get full rectangular panels for the backs to do analysis for target thickness. Two OM sized templates just barely fit. I have milled the side sets to the minimum rectangles needed to to fit two of my side patterns; much bigger then a normal back half panel. I'm aware that larger than normal half panels can create problems with getting good spectrum results, but I don't really have any options here.

The tested panel ended up 838mm X 256mm X 3.3mm.
The density is 993.37 Kg/m3

Using the above sized panel, the results so far show a consistent fl freq. at 16hz.
The fc showed either 49 or 83 or 122hz.
And the fl/c was either 21 or 51hz.

I have tried all the combinations in my spread sheet, but that leaves me with more questions then answers. Has anyone else attempted this, or have any input for me as to which might be the correct numbers to use.

Thanks,

Eric

Four piece rosewood set

[Trevor Gore]

For non-rectangular pieces, e.g. a rectangle with a corner cut off, choose a part of the panel that is rectangular and do a three point bend test on that part. Page 4.30 Design.

[AKEric]

Thank you Trevor,

I looked at that page and it's a section summary, none of which talks about a three point bend test. I also reviewed the panel tap testing sections of both Design & Build books, but could not find any information on this. Could you elaborate more on this three point bend test, or re-point me in the right direction.

Thanks so much,

Eric

[Trevor Gore]

Sorry about the typo. Should have been p 4.39.

[AKEric]

Thanks for the re-direct Trevor. I had read that, but didn't correlate the two subjects.

Eric

[johnparchem]

I just had to do this, and I posted the steps I took earlier this month. I at least tried to use the information from the Book. Link: viewtopic.php?f=33&t=8707

[AKEric]

Thanks for this John, I didn't see your reply until just now. I guess I should have done a search before starting my post. Your info is very helpful.

Eric