grande maestro liutaio, fino all'esasperazione, grazie per i doni che ci offri, sono doni incomparabili; suo grande affezionatissimo Franco Malfara'. Ispra (VA).
Hello Maestro, I'm using your videos as a complement of my lutherie classes and they're helping me a lot. I have a question. Before you start doing the tilt, why the upper and lower blocks are slightly off level compared to the C blocks? I mean the soundcheck you do tapping the block against the glass. Thanks!
Keeping the C blocks slightly higher is useful to prevent them from ending slightly lower (especially compared to the lower block), causing the plates to sink from the beginning, which would be the opposite of what is desirable
Great supplements for study!! In this video the inclination starts from somewhere interior of upper corner block to top block(on tavola and also fondo both sides). Would you recommend apply this also to the cello?? If so, how many millimeters these inclination should be?? One more thing, I guess making this inclination is in someway relates to the way that put some tension on the top plate bending it a little bit when we glue the basebar and it make sense. But would it be weired consequently if I make the inclination on the ribs but no tension on top plate with basebar, or other way around? Thanks in advance!
Yes, on the cello I would do the same, the measurements are proportional to those of the violin. This detail is not very visible on ancient cellos because of the large deformations of this instrument, so I can't be sure but I believe it was like that, at least for the Cremonese. The tension of the bassbar is a personal choice and if you want you can also not do it, it is perfectly compatible with the inclination of the ribs. However, to obtain a tension-free bar when the top plate is glued and the box is closed, you must necessarily fit the bassbar by fixing the top plate on a frame that exactly reproduces the profile of the ribs (with the inclination). Otherwise, the tilt of the top could cause a reverse tension on the bassbar that is not a good thing.
@@DavideSora what about a no tension bass bar paired with a no tilt rib structure? Would this be a bad idea? Also do these decisions change depending on whether you are making a Guarneri or Stradivari model? Or is your method and theory the same regardless? Thanks :)
@@mrgolftennisviolin Well, I do both tension and tilt, so my response is pretty predictable. With the same arching, thicknesses, and wood properties, I would expect a premature collapse (sinking) of the top plate. Of course it could work if you compensate with stiffer wood, stiffer arching, higher thicknesses and a taller, thicker bassbar. But I suppose you will end up with too much weight for my taste, but not all luthiers think like me and many do as you say or in all other possible ways (no tilt, no BB tension, or tilt and no BB tension, or no tilt but BB tension)😊. It is a complex system that must reach a balance based on the objectives that the luthier sets himself, there is no absolute answer.
I’d like to build my first violin. What carving gouges do you recommend or that are must haves for shaping the top and back plates and the scroll? If there is a website where these are listed, please add the link. Love your videos which show how much you care into making those instruments!
Sorry for the late answer, I hadn't seen your question until now🙁 These are the gouges and chisels that I use for the various tasks : Keywords Brand names : Wolf, Dastra, Henry Taylor, Stubai N° : the sweep number engraved on the gouge, an indicator of the curve but applies only to gouges of the same brand Width : the width at the cutting edge, measured with a caliper Radius of curvature : draw a circle of given radius and mark the indicated width, to obtain the real curve of the gouge ; superimpose your gouge to the circle to see the correspondence of the curves. Use : main use of the gouge Scroll carving Wolf n°4 - width : 22 mm - radius of curvature : 60 mm use : pegbox and carving (scooping) of the volute Dastra n°6 - 18mm - r 17.5 mm carving of the volute and first turn vertical walls Henry Taylor n°6 - 17.5 mm - r 13 mm first turn vertical walls and carving the start of first turn Henry Taylor n°6 - 10.5 mm - r 10 mm vertical walls of turns, carving first and second turn Henry Taylor n°7 - 10.5 mm - r 6 mm second turn vertical walls and carving first and second turn Henry Taylor n°8 - 9.2 mm - r 4.5 mm eye vertical walls, carving end of second turn and flutings of back Stubai n°6 - 6.3 mm - r 3.5 mm cutting and carving the beginning of the eye Wolf n°3 - 4.7 mm - r 10 mm incise the base of turns and flatten the flutings of back Top and back plate channel (fluting) Wolf n°6 - 13.7 mm - r 13 mm channel of upper and lower bouts Wolf n°7 - 11 mm - r 7 mm channel of back C-bout Henry Taylor n°7 - 10.5 mm - r 6 mm - (see scroll) channel of top C-bout Henry Taylor n°6 - 10.5 mm - r 10 mm - (see scroll) blending channel at corners Top and back plate archings and hollowing (thicnesses) Dastra n°3 - 35 mm - r 200 mm overall roughing of arching, fine hollowing (thickness) Wolf n°5 - 23 mm - r 38 mm C-bout roughing, blending of the channel after purfling Dastra n°6 - 35 mm - r 35 mm rough hollowing (thickness) Chisels 22 mm Various uses 18 mm Neck mortise 12 mm Various uses 10 mm Various uses 8 mm Pegbox - Various uses 6 mm Pegbox - Chamfers - Neck mortise sides
Hola Maestro Davide. Estoy haciendo un violonchelo y no sé cuánta inclinación dar a la tapa y el fondo. Sé que en el violín es de 1,5mm y 0,5mm respectivamente y que usted dice que debe ser proporcional pero, ¿en el violonchelo?, ¿cuántos mm exactamente? Muchas gracias por compartir toda su sabiduría.
Per i violoncelli antichi è più difficile capire quanti mm è questa inclinazione perchè sono sempre molto deformati, ma la mia supposizione è che siano 3 o 4 mm sulla tavola e 1 o 2 mm sul fondo, a seconda anche della lunghezza della cassa che può variare anche molto. Io preferisco 3 mm sulla tavola e 1 mm sul fondo.
Ciao Davide, Your videos are terrific! Could you tell me the overall length of your plane used for the the ribs and also the cutting angle of the plane. Thank you.
Thanks!😊 I use three planes in this video: the little one at 1:46 is 38 mm length, blade width 13 mm, cutting angle 40°, the one a little bigger at 2:54 is 85mm length, blade width 22,8 mm, cutting angle 35°, the bigger one at 7:16 is 135 mm length, 30mm blade width, 18° blade angle (low angle plane). But in this last case (as in all low angle planes) the blade is reversed compared to the other two planes, so the sharpening angle of the blade make the actual cutting angle at about 35° anyway.
Hello Mr.Sora. May I ask you one question?? (5:20) If the heights of all blocks are same, how the tapping sound of the blocks on the glass plate could be different?? I mean, how can you leave the upper&lower block a bit raised maintaining the same height? Thanks!
You're right, obviously the height will be slightly lower, but very little is needed to get this, probably about a tenth of a mm on the total height. So substantially the height is the same.
Davide Sora Thanks for the reply. understood, so it's a very delicate difference. But could you inform me why this process is needed?? (checking a slight difference of the sound). The height of upper-block side would be eventually changed, no? (although lower would not be)
This serves to make sure that cornerblocks are always prominent compared to the bottom and upper block (the upper one will be lowered further later anyway ) ensuring convexity and avoiding concavity in the plane of the plates, that for me is important for structural and also aesthetical reason. Giving a direct acoustic value would be rather complicated, but I am convinced that there is. You can find this situation in practically all the ancient Cremonese instruments (Strad, Del gesù, ecc.), which would in itself be an excellent reason to do so😋
Ciao Davide scusa la domanda forse sciocca... Facendo l'inclinazione anche dal lato del fondo quando andrai ad incollare il fondo non si rischia che le fasce flettano...?
L'inclinazione sul fondo è solo di 0,5 mm e non comporta granchè come deformazione delle fasce, considerando che il piano originale del fondo, in seguito allo scavo dell'interno per fare gli spessori, si deforma inesorabilmente anche più di 0,5 mm a causa delle tensioni interne del legno che vengono "liberate" causando una apertura verso l'esterno del piano. E' proprio per ovviare a questo inconveniente che si usano i pioli di posizionamento tipici del sistema cremonese : quando le fasce sono incollate al fondo tenderanno ad avere i tasselli più aperti rispetto al segno di riferimento sulla tavola, ma una volta posizionata con i pioli tutto viene riportato alla condizione originale o quasi. C'è anche da dire che se le fasce sono state piegate in modo da non avere tensioni e se la venatura e la fibra del legno del fondo sono correttamente dislocate i problemi di queste possibili deformazioni sono talmente minimizzati da diventare trascurabili.
If you go lower than 30 mm the stiffness of the corpus is reduced and the violin will bend too much under string tension, if you go higher over 32 or 33 mm the sound is more like a viola, not good for a violin. In the range 30 / 33 mm the frequency of the A0 mode (lower inside air mode) will go up or down in frequency.
Nessun criterio in particolare, le fasce regolano la rigidità della cassa e il volume d'aria interno. Non è molto efficace variare il volume d'aria con l'altezza, le variazioni sono troppo piccole per essere effettive senza fare cose estreme, ma la rigidità complessiva è un aspetto più interessante da meditare.
grazie per la risposta; come mai i violini famosi, anche dello stesso autore, non avevano la stessa altezza? era solo per regolare l'elasticita' e il volume? quindi ci dovrebbe essere un criterio a meno che anche Stradivari andasse per tentativi
non ne ho idea, ma molti strumenti sono stati modificati dai vari interventi di restauro e conseguente apertura/chiusura della cassa. Comunque sulle forme originali di Stradivari è segnata praticamente sempre la stessa altezza di fasce 32/30 mm
