Back thicknesses from start to finish (condensed)
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- Опубликовано: 7 фев 2025
- Davide Sora - Liutaio - via Decia 22 - Cremona
Scavo del fondo di violino e finitura degli spessori dall'inizio alla fine (condensato)
Hollowing and thicknessing of a violin back from start to finish (condensed)
Indice dei video (italiano) : davidesora.alt...
Index of videos (english) : davidesora.alt...
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I' ve seen your videos a million times each!! Thanks a lot for showing the whole process!!! In you opinion.. what tuning is better for the back of a violin having the top plate tuned in Fa#? Thanks a lot
With the top in Fa#, I would like to have the back in a range between Fa and Fa#. But frequencies alone don't say much, you have to correlate them with weight and thickness. So if a back at Fa# was still heavy, and if the thicknesses allow it, I would thin it to reduce the weight and lower the frequency towards the Fa. However, if the weight were already light, or the thicknesses already thin, I would keep it around Fa#. Generally speaking, a light plate, with high frequency and not too thin thicknesses would be desirable, but this would require high material properties.
In any case, it is not a matter of tuning the plates on specific frequencies, but of using the frequencies as an indicator that can give us useful information if correlated to all the other information we have on those plates
@@DavideSora thanks a lot
Very good videos all are very useful!!!
Can you send images of you carving glove please
It is a simple leather strip 2,5 mm thick with two holes for the fingers, I made mine starting from a leather strip 25 x 10 cm by doing the two holes first and then cutting out the shape approximately around my palm, cutting the two fastening stripes in a "V" shape to accomodate the wrist.
Ever tried a magnetic thickness probe to measure the back thicknesses once you have roughed it out?
Why? It is much more practical to use the traditional thickness gauge, and also more accurate.
Thank you once more for demonstrating and sharing this knowledge which is invaluable for amateur makers like myself. The area’s marked on the inside of the plate are they a specific size? For example the thickest area is that in the centre of the plate, and is the bullseye pattern area’s a certain size? I’m just starting to carve the inside back plate so would like to follow your example. Thank you again take care 👍
There is no predetermined size, because it depends on the property of the material and on the shape of the arching curves, normally the area is more extended in the flatter archings and narrower in the more curved ones, due to the different stiffness of the resulting archings.
@@DavideSora Thank you, would I be correct in guessing that as you tune the plates you’ll be scraping different areas to achieve the required note, and so so areas will be different.
@@bluehoo0 Yes, by thinning the thicknesses and progressively reducing the extension and shape of the thicker central area of the back plate, you get a progressive reduction in stiffness (which can be controlled through the frequencies of the tap tones for a given plate) and also in the weight. These two factors together can give a fairly accurate idea of the behavior of the plates of a given outline model. It is important to consider the weight too, because the frequency alone is not reliable, in the sense that you could reach the same note (frequency) even with different arching shapes and weights, with different acoustic results even with the same tuning. The arching is much more decisive for obtaining good results, the thicknesses are only a consequence and there is not much space to correct any errors of the arching, which will always predominate on the final sound. Thicknesses can only optimize the arching behavior, but if your arching is not good they will not work miracles, even if you manage to get the tuning spot on.
@@DavideSora Thank you David I think I’m starting to understand what’s required, once again THINK I’m starting to understand. Violin making is probably best learned through an apprenticeship as you can be taught what to listen for at each stage of carving. As apposed to learning to make furniture or carpentry from a book, were if your work looks the same as the pictures then you’ve made a good job of it. A violin might look like the picture in a book but it has to vibrate correctly. Learning from books and RUclips as myself and other’s are, to some extent we are shooting in the dark regarding sound. Having said that I find it extremely enjoyable and educational, and a good retirement hobby. Although my wife complains I spend to much time in my shed🤣🤣🤣
@@bluehoo0 I understand your wife😊, making violins is really an expensive hobby, it takes a lot of strange tools, but is also very rewarding if you like handwork. Regarding shooting in the dark for sound, the violin is a structure with extremely complex vibratory behaviors, not even the most advanced scientific studies have been able to give definitive answers, that's the reason why we must still rely on our experience and intuition, no one shoots in full light...
Hi maestro im interested thicknes edges viola back board 2.2 minimeters
I don't quite understand what you mean. The thickness of the edges? The thicknesses of the plate? What does 2.2 minimeters mean?
Thicknes plate the edge inside
@@andrzejtruchan5236 The thickness inside the edge is practically the same as in the violin, just a couple of tenths more. As always it depends on the size of the viola, the larger and wider it is the greater the increase in thickness compared to the violin, based as always on the density and hardness of the wood. There is no fixed rule, but the thickness of the violas is proportionally smaller than that of the violin (not in an absolute sense, but in proportion), because they need a less brilliant timbre, therefore less rigidity of the plates. At most you get half a mm more than the violin, in the case of maple. With other woods the situation would be very different, based on their hardness and density and grain orientation
Excellent videos. Thank you. Out of curiosity, how many times did you have to sharpen your gouge when doing the roughing in of the back?
Usually I refresh the sharpening of the gouge on the stones only once before starting roughing, if the steel is of good quality and the bevel angle is correct (not too tight) this is more than enough.
Greetings, the step wedge used for setting the thickness for the punch where do one find this. I made the thickness punch and tried but failed making the step wedge. thanks
This is strange, it is not difficult to make the wedge. Simply flatten one side, saw the wedge, flatten the remaining sawn side and you're done. Then measure it with the caliper and make a mark in correspondence of every half mm thickness. Anyway, if you like to spend some money there are a lot of options, here is one for example : www.amazon.com/Taper-Welding-Gauge-Gage-Feeler/dp/B07F8S74JC/ref=pd_lpo_60_t_0/136-0300013-0279802?_encoding=UTF8&pd_rd_i=B07F8Q8NPK&pd_rd_r=be2185bf-858c-4115-975d-cbec338a14a7&pd_rd_w=01grd&pd_rd_wg=AYrQj&pf_rd_p=7b36d496-f366-4631-94d3-61b87b52511b&pf_rd_r=PA239SGAXYM544JVJN3V&refRID=PA239SGAXYM544JVJN3V&th=1
@@DavideSora thank you. I did think of making one but thought it wouldn't be accurate as a factory made. Thanks for the sites. Ever think about about putting notes into book form?
@@larrycounce4509 In reality, the wedge does not need to be extremely accurate, because once you have made it, you can check the thicknesses that will result by measuring them directly on the plates and then adjust accordingly in the future thickness gauge adjustment. However, another accurate system for setting the measurement on the thickness gauge is to use the smooth rod of the drill bits, which you can find with differences of half a millimeter or even less if you like.
Sometimes I think about making a book, but it's a lot of work and at the moment I prefer to make violins.😊 Maybe in the future, who knows...
@@DavideSora good idea using drill bits never thought of that, having said that I have made a wedge from a piece of oak.
Hi maestro thanks so much
For explaining mee the bassbar
I'm ged questions about
Viola
Wich place thiknes give mee low tone
C-dur
G-dur
Wen I'm play g string 3 finger I'm need low C-dur
Wen I'm play d-string 3 finger too
G-string I'm need low tone si. ...do..
D-string I'm need low tone do..
I don't now wat too do
Now is hig tone
What is the size of your viola?
This viola 410 mm
Unfortunately there aren't such analytical and specific indications that can be given, it all depends on many factors that must work well together. However, violas need a proportionally thinner top plate than violins, a thinner thickness generally shifts the amplification of frequencies towards the lower range. But if the top gets too pliable, you'll end up with several wolf problems, and also some structural warping issues.
Anyway, it is not possible to give indications without knowing what viola it is and how it is made in reality, seeing it with your own eyes and hearing it with your ears, you should take your viola to an expert luthier and hear his direct opinion
Thanks for information
I know is wery hard too doo
This tone
What is the max thickness of the center? Thanks a lot.
This is just a very condensed summary video, you can find all the measurements and a lot more detailed information in this other video : ruclips.net/video/7W9a3V4TxFQ/видео.html I made a series of 12 detailed videos on top and back plates thicknessing, you can find them in this playlist : ruclips.net/video/f6kCD4XtaZ4/видео.html
You can also find the full index of all videos with direct links on this page of my website : davidesora.altervista.org/videos/
Great video Maestro! i'm building my first viola based on Andrea guarneri Conte Vitale, which frequence me advise to leave for mode 5?
For my Andrea Guarneri viola form (41,5 mm body lenght) I would like a M5 frequency in the range from C to D (from Do to Re).
My last Viola had the back M5 at 297 Hz (Re+), maple back quarter cut, weight 134 g, density 0,58 g/cm3
The top plate M5 was at 258 Hz (Do-) without bassbar, raised at 285 Hz (Do#+) with bassbar (84 g weight, 0,39 g/cm3 density).