Spessori del fondo parte quinta - Messa a punto finale a rasiera

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ENGLISH TRANSLATION of the written notes in the video, in order of appearance :

00:05 - Back plate thicknesses part five - Fine tuning of the thickness with scraper

00:12 - Using an adjustable thickness gauge set to the appropriate measurements (4 mm, 3.5 mm and 3 mm), draw the lines to visualize the distribution of the thicknesses, consisting essentially of fairly regular rings sloping down from the center of maximum thickness. Modify them according to the necessity avoiding to weaken too much the central part between the C and the soundpost area, thinning more the upper and lower bouts to confer them the necessary elasticity.

00:46 - Periodically check the frequency of the highest note (mode 5), the weight and elasticity of the back to decide whether to further thin the thickness by tightening the rings towards the center. My preference is for a note between Fa and Fa # (from 350 to 370 Hz), a weight between 95 g and 115 g (wood density between 0.55 and 0.65 g / cm3) and for a fairly good stiffness of the central part associated with a good flexibility of the upper and lower bouts and at the corners.

05:07 - Define the gluing surfaces of the upper and lower blocks by marking the measurements taken from the ribs. Draw a curved line wider than the block (80 mm) for the lower one and remove the excess wood on the sides. Instead, draw a straight line for the upper one, to avoid weakening this area subject to the bending induced by the neck. Avoid digging too much the areas facing the blocks so as not to weaken them too much, leaving the gluing surfaces abundant by 0.5 mm compared to the actual block size.