OO cutaway
Posted: Sun Apr 14, 2024 7:11 pm
Good Afternoon all,
Well, No.2 is officially finished. This one only took 18 months...
It's an OO size, 12 frets to the body, cutaway using the building techniques I've very amateurishly applied from "The Books". Body 460mm long, 360mm wide at lower bout. Too many mistakes, blunders, and mishaps to list. Which lead to multitudinous re-do's, reworks, and repairs. Learned a lot. Cursed a lot. Mostly enjoyed it.
The knot you see in the neck only became apparent as I was carving the profile. Rather than start again, I filled with saw dust and superglue and kept on going. Worked out OK, and now it's a feature... not a fault.
Finished build tap testing resulted in;
T(1,1)1 - 109Hz
T(1,1)2 - 197Hz only 1 Hz off G at 196Hz. It really did make the guitar jump on the low G!
T(1,1)3 - 232Hz.
Turns out my build was very sensitive to adding side weight and so I only needed half of what Fig. 2.3-15 suggested. Adding 2 steel sections of 70mm x 40mm flat bar equalling a total of 233g side mass.
New tap testing results:
T(1,1)1 - 108Hz
T(1,1)2 - 190Hz - between F# and G. Very nice! No more boomy G's.
T(1,1)3 - 226Hz.
I measured top deflection using 2 different weights;
1. weight: 477g = 4.68N. deflection: 0.05mm. K = 93,600N/m
2. weight: 957g = 9.39N. deflection: 0.11mm. K = 85,363N/m
I used the average of these - 89,482N/m to calculate monopole mobility of 13 x 10(-3) s/kg. Which according to Design section 1.7.2 makes this guitar officially "Good"! Sure sounds good.
Well, No.2 is officially finished. This one only took 18 months...
It's an OO size, 12 frets to the body, cutaway using the building techniques I've very amateurishly applied from "The Books". Body 460mm long, 360mm wide at lower bout. Too many mistakes, blunders, and mishaps to list. Which lead to multitudinous re-do's, reworks, and repairs. Learned a lot. Cursed a lot. Mostly enjoyed it.
The knot you see in the neck only became apparent as I was carving the profile. Rather than start again, I filled with saw dust and superglue and kept on going. Worked out OK, and now it's a feature... not a fault.
Finished build tap testing resulted in;
T(1,1)1 - 109Hz
T(1,1)2 - 197Hz only 1 Hz off G at 196Hz. It really did make the guitar jump on the low G!
T(1,1)3 - 232Hz.
Turns out my build was very sensitive to adding side weight and so I only needed half of what Fig. 2.3-15 suggested. Adding 2 steel sections of 70mm x 40mm flat bar equalling a total of 233g side mass.
New tap testing results:
T(1,1)1 - 108Hz
T(1,1)2 - 190Hz - between F# and G. Very nice! No more boomy G's.
T(1,1)3 - 226Hz.
I measured top deflection using 2 different weights;
1. weight: 477g = 4.68N. deflection: 0.05mm. K = 93,600N/m
2. weight: 957g = 9.39N. deflection: 0.11mm. K = 85,363N/m
I used the average of these - 89,482N/m to calculate monopole mobility of 13 x 10(-3) s/kg. Which according to Design section 1.7.2 makes this guitar officially "Good"! Sure sounds good.