Top Mass

[ScottC.]

Hey Trevor, in the design book on page 4-63 you mention that a couple of top woods in the chart (4.5-3)has to much mass to be a master grade guitar, is there somewhere in the book that explains the amount of acceptable mass?
BTW I just did the procedure to find the top thickness on my first Engleman spruce top, it worked but my thickness number with a "60" "f" came out to 2.35 which is a bit thinner that most of your examples. Is it normal for a classical top to be thinner?
Thanks, Scott C.

[Trevor Gore]

is there somewhere in the book that explains the amount of acceptable mass?

The top mass depends on the size and shape of the guitar as well as the top's material properties, so whether a top is too heavy or not for a particular design can only be compared to your experience with that design.

BTW I just did the procedure to find the top thickness on my first Engleman spruce top, it worked but my thickness number with a "60" "f" came out to 2.35 which is a bit thinner that most of your examples. Is it normal for a classical top to be thinner?

That's in the right ball park for a classical top because, yes, they are normally thinner. Run the numbers again with f=75 and see if you get in the right area for a SS top, which will provide you with a check.

[ScottC.]

Thanks, I need to get busy building, to try all the different ideas and factors.
I used f=75 and it came right in close with the chart in the book 2.94
Thanks again, Scott