NEW BUILD tap testing Englemann

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yakka
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NEW BUILD tap testing Englemann

Post by yakka » Sat Aug 04, 2018 10:15 am

Beginning new build 00 size very similar to a Gilet 00. this is for one of my sons and he has chosen some Engelmann for the top so we have tap tested the top for the following results.
2nd.PNG

I contacted Kiwigeo (who i received the wood from) and martin was able to confirm that the figures were close to similar timber he had records for
Martins.PNG
Martins.PNG (52.8 KiB) Viewed 694 times
I used Spectrum Analyzer on my phone after reading Steve Toscano's review, initially had trouble getting the Fc so changed my tapping tool from knuckle, to rubber on the end of a sharp chopstick (worked well).

Any comment would be appreciated, some time since I did the course and had used the formula.

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Trevor Gore
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Re: NEW BUILD tap testing Englemann

Post by Trevor Gore » Thu Aug 16, 2018 11:44 am

yakka wrote:
Sat Aug 04, 2018 10:15 am
Any comment would be appreciated, some time since I did the course and had used the formula.
Lower bout at 380mm is large for a 00 sized guitar. They are usually around classical size at 360-370mm. I recently measured one of Gerard's 00's at 370mm. I think CF Martin make them a little smaller than Gerard's version.

yakka
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Re: NEW BUILD tap testing Englemann

Post by yakka » Fri Aug 17, 2018 2:41 pm

Hello trevor,
hope you had a good trip,
Just re-measured and its 378 across the lower bout, I see their website they are 368. so maybe this is 00@1/2 somewhere between the 00 and 000. Beautiful sounding instrument if we can get close to the quality of sound it would be very pleasing.
Just looking at the frequency responses can you tell if a particular piece is stiff across the grain, ie high Fc equals stiff piece of timber across the grain.
Any more pictures of your rosette/router set up
thanks for responding
regards
Chris
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Trevor Gore
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Re: NEW BUILD tap testing Englemann

Post by Trevor Gore » Sat Aug 18, 2018 12:25 pm

The trip was very good, thanks. Was over with Robbie O'Brien doing the Modal Tuning Course a couple of times.

Nice burst on that Gilet guitar!
yakka wrote:
Fri Aug 17, 2018 2:41 pm
Just looking at the frequency responses can you tell if a particular piece is stiff across the grain, ie high Fc equals stiff piece of timber across the grain.
A high frequency tap tone tells you that you have high E*I (Young's modulus * 2nd moment of area), so just the wood being thicker means it taps higher. You have to work out Ecross to get a comparative measure. An Ecross over 1GPa is pretty stiff wood across the grain.
yakka wrote:
Fri Aug 17, 2018 2:41 pm
Any more pictures of your rosette/router set up
Thanks for reminding me! I'll put those in another post to make it more easily searchable with a link from this thread.


yakka
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Re: NEW BUILD tap testing Englemann

Post by yakka » Sun Aug 19, 2018 10:17 pm

thank you,
your a good man
regards
chris

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