On the strad poster of the Lord Wilton it has 17.7mm for arching height of the belly , is it really that high , looking at the side view compared to the back I have to question if this measurement is correct . Has anybody reproduced this arching height or seen the Lord Wilton in person to gauge the height of the belly . cheers Adam
Good question ... like most old violins, the Wilton has some twist in the top. So the arching height at the highest point along the long arch will be different from the height measurement across the violin at the same spot. That's why those arching guides taken off original instruments hardly ever work together as a whole ... unless you're willing to create a distorted top yourself and then fit your ribs to it etc. Where does it end?
Keep in mind, the top archings we see today on old violins are hardly ever the same height as they were when that violin was new. If you copy an arch as it is today, what will your violin be like in 250 years? Unless you are consciously creating a replica as a learning project, I think its best to study old violins to see how they work, generally speaking, and then follow that. You will be better off than thinking that exact replication of a distorted arch will produce the tonal results of the original.
That said, I do think some variations or asymmetry in the archings may produce a more complex sound ...compared to perfectly matched archings (from T side to B side). But I have no proof of that. Its just a hunch. Reading the other postings, I can see that you now have a whole range of heights to pick from .... 13mms to 17.7 !!! The last Wilton I made was 15.5 along the long arch.
Bernie ... yes, the e-string, in particular, should be loosened when adjusting the sound post. Some adjustments involve moving just the bottom of the post. Even then ... maple too can be damaged by careless work. We shouldn't go into this too much ...lest we egg-on any players out there who like to 'self adjust' ... but one peeve of mine is the damage often seen from SP setters being planted on the inside of the back. I use a heavy SP setter and prefer to tap the post instead. Just the sound of the tapping tells me something about the tension and the fit of the post. The same is true for the small twists or swivels that can occur when a post is not fitting perfectly. You will never see that information when adjusting the bottom of the post with the tension up.
Fiddledoug ... I just told the truth, which has a way of standing up on its own. Plus, a google search probably brings up Vuillaume's dates right in his wiki header on the first page.
The alignment marks are only intended as a reference point. Its a lot easier to layout the center line of the instrument and the bridge foot position etc. with the top off. And you have to do that first anyway in order to set up the bass-bar position.
I do agree, the final adjustment is dictated by sound ...and the more eccentric an instrument is, the more the final position may vary from what was expected. With new instruments, we have the luxury of fairly consistent archings and graduations etc. and the optimal set up positions are more standardized. This Vuillaume was made with a fairly normal Strad pattern. Laying out the setup was fairly straight forward.
One thing that never ceases to amaze me is how much change can be made in an instrument's sound by soundprost adjustments so small that they are hard to chart even with the benefit of reference lines on the inside. Nevertheless, l like to keep accurate notes about where a SP was left and imagine other makers have methods of their own for doing the same.