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19.4
Started with the back plate. The wood is not high performance, but it has a nice clean ring. It's also hard and even.

22.4 
I worked the arching down to the check point (Table 12) and it's the lowest ringing wood so far. Height is 17,5 mm now. The predicted weight is 100-102 g

27.4
Cutting purfling groove and thinking about buying a Dremel, but then again, how authentic is that?

29.4
Purfling done 2 hours of intensive and messy work.

1.5
Arch shaped 17,3 mm high, difficult to keep frequency at it's reference which also low C (~4000 m/s) and ring check indicated. 50 g yet to be removed

4.5
Arching done. STL lines are narrower and arch height 16,5 mm. I think I managed to get to the limit of what was possible with this wood.

4,5
Just needed to know so I hollowed out the inside to 140 g. M5 = 420 Hz. i.e. slightly above it's reference. I left a little margin to graduate from the outside at final stage

7.5
Back plate tuned to 345 Hz, 102 g. Arch also lowered to 15,8 mm.

I'm inspired by the "shoe polish" Strad, so I pushed this back plate to graduations a like.
 
Graduations:
Sound post area 4,4-4,5
Middle 3,8 - 4,1
C-bout edges 3,3 - 3,6 
Upper regions 2,0 - 2,5
lower regions 2,1 - 2,7
Edges 2,3 - 2,5

Back 2014



11.5 Final stage of the back plate, drying in UV box at 40 °C, ~2 % RH. The plate has lost 4 g and EMC is about 3 %, M5=350 Hz. I made charts of the tuning procedure Extrados/Intrados (outside arch/inside arch) The Extrados figures are under copy right.

Back 2014 Final stage