Doc Eastman

Correct. This was difficult for me to grasp when I started! I was taught to express this angle as 6.5 rather than 90-6.5, but have seen it both ways. I set the protractor at 83.5 however. Expressed either way, when the neck is fit to the block the face of the neck (may not be using the correct terminology) is usually about perpendicular to the ribs. As mentioned previously, I do not use this angle to fit the neck, using the projection of the fingerboard onto the bridge (fit to the top and in the right position)to determine the angle of the mortise. Once I make the cut in the top 7mm from the top edge I don't touch this finish cut. The mortise may actually deviate a little from perpendicular one way or the other depending on the arch. Before I fit my first neck I made up a mock violin neck end with a replaceable block and fit a neck about 10 times. Practice helped in getting good joints.

I was taught and to measure 7 mm in from the top edge (so neck from lower edge of button to top end of neck is 137 mm), measured in the midline. If overhang is 2.5 and rib 1.2, then the cut extends 3.3 mm into the block at the midline, less at the edges depending on the curvature of the top. I was also taught to cut the angle of the neck root at 5.5 degrees, which meant that the mortise was a little deeper at the button, in order to achieve the correct neck angle/projection onto the bridge. I now cut the angle at 6.5 degrees and the mortise is about the same depth top to bottom, but do whatever it takes to get the neck angle right (per H. Strobel I use the projection of the fingerboard top onto the bridge rather than the height over the arch at the end of the fingerboard as the metric for setting the neck angle).

I posted that good maple for ribstock is not available to match the back. However, a cello neck block is a good source of rib material if you have a bandsaw setup for resawing thin slices. I just set up my Grizzley 14" saw with a 3/4" blade (not the carbide imbedded type) and was able to saw thin slices (1.5mm) from leftover pieces of a cello block. If you want highly flames ribs probably better to buy them directly (int. violin, for example sells highly flamed finest-flamed violin sides for $33/set, and nicely-flamed for $6.50, other suppliers may have better prices). In contrast, a slightly flamed cello neck block is $63, and select finest-flamed block is $285. Resawn ribs still have to be dimensioned. I thickness sand the inside surface with a "Luthier's Friend" drumsandeer/jig), and use a cabinet scraper on the outside. As I have become more confident in my planing, I am also planing the inside surface. Hope this is not too much info but think my experience as a beginner with about 12 instruments experience might help other people new to making these instruments. I have no conflict of interest and no vested interest in int.vio...<grin>

Have you tried an instrument cleaner/polisher compatible with your finish? Depending on value of he instrument, I might try french polishing (rubbing with a soft non-abrasive pad) with olive oil, and depending on the finish state a slight dusting of very fine pumice (I rub out all my finishes with this method). Could also use mineral oil i same way. If it is a fine instrument I would take to a luthier.

Does the varnish smell or the cavity, or both, if you can tell?

BA survey was carried out on wood workers and on a group of unexposed, healthy controls. One group of wood workers (group A) were asymptomatic and another (group had symptoms either of chronic cough and dyspnoea on exertion (B1) or dyspnoea at work and bronchial hyperreactivity (B2). The control group (group C) was randomly selected from among a population of laboratory workers. No significant differences were found among the groups with respect to the frequency of atopy but the prevalence of a positive skin reaction to wood extracts was significantly higher in the asthmatic subjects. The adjusted FVC and FEV1/FVC% were significantly higher in B1 than in the other groups; the FEV1 was lower in B1 than in B2 and in B2 than in the other groups; TLCO and KCO differed significantly in all four groups. A significant negative correlation was observed between FEV1, MEF50, TLCO and KCO and duration of exposure to wood dusts. The alveolar volumes were not significantly different between the groups and were not correlated with duration of exposure. These results confirm the observation that exposure to wood dust or to some bronchoreactive substances linked with wood working can induce chronic obstructive lung disease (COLD). Some cases of wood dust asthma seem to be related to an immediate allergic reaction, but precipitating antibodies appear to be an index of exposure rather than of disease. The decrease in diffusion capacity can be ascribed to a thickening of the alveolar capillary membranes secondary to an alveolitis like, non-symptomatic, allergic reaction.eware finely dispersed wood dust. Occupational exposure can cause serious lung disease. See this abstract:

Since so many people in a field of interest have real or perceived conflicts of interest, the approach in medical research is for everyone involved to file their conflicts of interest in writing, so they are available to people who review the data, publishers, and people who read the study results. If someone has a vested interest (stock holder, or could otherwise materially benefit from the results), they should be excluded from any critical vote or result. In clinical trials they usually leave the room during critical discussions and voting, as their very presence may bias other participants who might not want to offend the vested person. So if a maker placed a violin in the trial and then participated in the testing, their conclusion must be excluded from the data analysis. IMHO they should not have been present during the test. In the test under discussion if probably didn't make a difference, since most gave the wrong answer or couldn't tell.

Internationalviolin.com provides pre-cut and thinned rib stock for violin, viola, cello, and bass, matched to the maple back. They give you enough extra that you can afford to waste some learning to bend. Not directly related, but it is much easier to bend ribs on a bending iron if you have a piece of lead sheet (rib is between sheet and iron) that distributes and holds the steam better and reduces break-out. I have opted for this because stock matching the back is not available. You can resaw a maple board, but you need a good bandsaw and a wide blade (3/4")for rewsawing. My teacher uses an old modified (shimmed down to get to ~1.5-2mm) Ryobi thickness sander to thin resawn rib stock. I have priced one that can sand to violin rib thickness, runs about 1K. You can buy enough ribs for about 30 violins for that amount, so I have passed. I use an inexpensive drum sander with a jig to get the purchased stock ribs down to the thickness I want.

Sx only very late. Elevated blood calcium and high 25-OH-vitamin D level(25 hydroxy vitamin D is made in the liver from dietary or UV converted cholesterol). Both are biologically inactive. The active metabolite is 1,25 -OH vitamin D. the second -OH is added by the kidney. 25-OH vit D level is routinely available and the best test for both deficiency and vitamin D intoxification. Levels of about 30 are considered normal (with the societies recommending 20-30 as the optimum for general bone health). Not unusual to see levels of 50-100 in people taking 4K. If you get some sun exposure it just adds to the total level. Generally 1-2K/day is ok and doesn't produce toxicity (people with kidney disease may need more and often if not always, need to take 1,25 dihydroxy vitamin D because they don't have enough functioning kidney tissue to activate the precursor hormone (25 OH vitamin D)).

We have been speculating on the time difference and wondered how many cups of coffee you were working on. Sleep well!

For those who don't look at audacity FFTs, softer is more negative. So -30dB is louder than -60dB. So violin 1 at -30dB - Strad at -60dB = a point that plots at + 30dB (-30-(-60)= +30)above the zero line on the plot, or louder on the violin 1 (modern) side. Gee I hope I have this right..algebra happened many moons ago.

I think you mis-typed d#4, as d#5 is 622Hz (at least according to my Wikipedia table...).

Anders, please clarify the difference spectrum. I am assuming that you are plotting modern dB-StraddB, and that anything above the 0 line on the graph, in positive territory, is louder.. Perhaps I have this wrong.

The modern is louder in the low end, with a big difference around C#4, where the strad is softer (hard to tell on a log scale however, Anders???). Is this the difference people are hearing? This could be very dependent on sound post placement/setup. Might be possible to set the two instruments up to have identical spectra, then test them for differences that are not apparent in the spectra (concert hall from back seats... )