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Relief Cut

Posted: Wed Feb 03, 2021 6:56 pm
by AluminumTop
Seeking knowledge
Has anyone on the forum done this ?
US Patent for Acoustic stringed instrument body with relief cut Patent (Patent # 6,759,581)
It appears to thin out the edge And effect the sound?
Can't put it back in once cut.
Did this invention fall flat?

Re: Relief Cut

Posted: Wed Feb 03, 2021 7:42 pm
by rcnewcomb
I believe that is part of the Taylor NT neck design. Others can correct me if I am mistaken.

Image

Re: Relief Cut

Posted: Thu Feb 04, 2021 12:27 am
by Skarsaune
I’ll have to look up that patent in the morning, but thinning the outer inch or inch and a half of a top, especially from the soundhole back, is pretty common to loosen up the top / increase responsiveness.

Re: Relief Cut

Posted: Thu Feb 04, 2021 9:00 pm
by AluminumTop
Here is the famous V image from the V patent with the cut
it seems to be a 1/4" router pass on the ole' CNC trimmer of the outer excess before going to the assembly jig. I'll try to see that on the next tour. (5 miles away)

Now it seems to me that cutting thru all that grain across the lower bout would weaken the structure a bit. (that's the point?) Maybe they have a "magic" depth of cut.
Is this visible inside the body?

The picture is from the tour.

Re: Relief Cut

Posted: Thu Feb 04, 2021 9:24 pm
by Skarsaune
Yup, it’s making it ‘weaker’ where that cut is.
Top is then looser, free-Er to move, more responsive.
Same thought as differentially thinning the top at the outside, just more extreme.

Re: Relief Cut

Posted: Fri Feb 05, 2021 7:56 am
by tippie53
this is not new but may never have been patented in the past. in 20 yrs of repair I have seen this in 2 guitars.
this area of the top is very structural to carry the load of the neck and strings. I have seen many guitars that failed in this area, There are 2 reasons
A the shrinkage differential and the neck load. In taylors with the bolt on makes the shrinkage moot. They compensate the neck block to carry the load. I have not heard a Taylor I liked yet . I had 1 sold it never got a feeling for it. Yes it was a nice guitar but it felt and sounded to sterile.

Re: Relief Cut

Posted: Fri Feb 05, 2021 1:28 pm
by AluminumTop
Thanks John,
I called the lawyer of the relief patent and asked if i can use this,
Yes.
I am going to test it on the OM model aluminum soundboard.
With Alum, There is strength in the web after the cut,
(isotropic grain structure)