JacksonMaberry

If he's using the one owned by the Jacobs Historical Performance institute, it's probably the one I made for them. They ordered four violins and two violas - one alto, one tenor. What's kind of fun is that they both have the same VSL, because I used the traditional tenor neck scaling, which you can see on the small handful of unbutchered Cremona (and Stainer) tenors.

Oh, ok I understand. So more of a musicological enquiry then. The book (more of a pamphlet, it's not long) can be bought from either Aquila Corde in Italy or from any of their licensed dealers, I believe. I've found it pretty useful.

Thank you, I feel better now! Yes, when you're hogging a neck heel, where you're cutting a bunch of curly maple endgrain, it's really nice to have a large(ish), robust, and well shaped edge. I've been in the process of replacing all my cutting tools with blades I make out of 26c3 steel, tempered very hard (~70 hrc). Being hard, they are more prone to chipping if the edge geometry is off or if I abuse them. On my new neck knife (which of course I use for other things as well), the edge is 2.5 inches long, with a reasonably strong curve. It's made of 2.8mm thick 26c3, 20mm wide. On this one, because of the heavy use and steel properties, I use a Japanese bevel. Haven't chipped it yet, and it's a really lovely little razor. In a pinch, I've used it to de-beard.

If you can find a copy of Mimmo Peruffo's book on gut strings, it contains formulae for calculating the appropriate gauge for a given VSL (vibrating string length). Mimmo is the founder and designer of Aquila Corde in Italy. I mostly make historical instruments and his strings are my favorite. If you can't make gut work, you can approximate the sound and feel of gut with the appropriate gauge of PEEK monofilament, lightly sanded with 600 grit paper to give the bow something to bite on. Multifilament is even closer to the gut sound, but difficult to source.

Happy to help! Sorry, I hope I didn't come off as a buzzkill or a know it all. I have spent so much time thinking about, researching, and then testing different methods of grinding, honing, lapping, etc. And then being the control freak I am, that has led me to designing and building my own tools/jigs/fixtures/machines. As I've gotten older, I've come to value my time more than I used to, and so if I had to do it all over again, I'd probably stick to something more or less off the shelf, rather than insisting on building my own variable speed DC grinders. In particular, I'd get a nice "slow speed/low speed/two speed" grinder, like the Rikon 1hp slow speed. On one side, I'd mount a nice 1.5" wide, 8" diameter "4 in 1" CBN wheel from Wood Turner's Wonders" - I have their square edged fat wheel, but this time I'd buy the 4 in 1 because the 1/4" radiused edge can be used to refresh the grind on my corner block incannels. I'd get the 80 grit this time, because I got the 180 when I built my grinder and, while it's pretty fast, I'd prefer it faster. As one of our friends said above, coarser is cooler! On the other side, I'd mount a MultiTool 2x48" belt grinder attachment. It's a really neat, flexible tool with belt quick changes. I'd make sure I had some super coarse ceramic belts for shaping new tools, and a variety of different Trizact belts for honing/lapping. I'm really fond of either a leather or a hard felt belt to charge with green chrome-ox compound for final polishing. Links to the key items I mentioned. Even though I'm all set on equipment, if I find myself with some wiggle room in the budget, I'll replace my kit with the setup I described above. Rikon Grinder: https://rikontools.com/product/80-808m-rikon-8-1-hp-motor-only-slow-1750-rpm/ CBN Wheel: https://woodturnerswonders.com/collections/cbn-wheels/products/4-in-1-plus-cbn-wheel MultiTool Belt Attachment: https://multitoolgrinders.com/products/multitool-2-x-48-belt-grinder-attachment.html With this rig and some Tormek or shop made jigs, there really isn't anything you can't grind or sharpen rapidly. Just watch out for your friends and neighbors, because you will end up being asked to sharpen all their axes, garden shears,kitchen knives, and the like. I had a buddy convince me to put an edge on his cheesy samurai sword! Anyway, have fun!

Personally, I'm not a fan of using the cheesy combo belt/disc for hollow grinding, where you're using the portion of the belt which is riding the wheel. Let me explain why - when hollow grinding, obviously the depth of the hollow is governed by the diameter of your wheel. A new hard white friable grinding wheel in the US is generally going to be either 6" or 8" diameter. Generally speaking, most home woodshops will use the smaller (though they're still rather large and heavy, which is a good thing) units which employ a 6" wheel, and I use one myself. Remember that the chief function and advantage of hollow grinding is that the two-point bevel makes for faster, easier, and more consistent indexing to the stone while honing freehand. The disadvantage is that a hollow ground bevel is structurally weaker than a Scandi bevel (which is a straight line), which is still weaker than a Japanese bevel (ever so slightly convex). Couple this with either (or both) aggressive hogging or a temper damaged by overheating during grinding, and you will find yourself frustrated by chipping or crumpling edges. Now back to the belt sander - the diameter of the bearing wheels on a belt sander is m u c h shorter than that of a 6" grinding wheel. This makes for a substantially deeper hollow - and therefore a substantially thinner, more fragile edge. What's more, a thinner edge with less mass behind it to act as a heat sink means you have that much less time to grind before you either must pause for cooling or burn the temper. All that said, if you'd rather pinch pennies, you absolutely can make it work. For me, a 6" diameter is as hollow as I'm interested in. I prefer a more robust cutting edge. Anyway, the choice is yours! Good luck, and Godspeed.

I went and looked up images of the instrument, and while it really is spectacular, both the images and this description actually suggest a rather un-Staineresque arching. The italics above are mine, and highlight the characteristics which do not really align with Stainer's habits, which much more resemble the best work of the Brothers (or more accurately, Girolamo I) Amati, especially the backs. In such instruments, the purfling generally sits just "uphill" of the lowest point of the channel on the edge side, with the channel itself being in general rather deeper than later Cremona work. The central cross arching of Stainer is in general fuller, descending from the center line towards the channel first very gently and then, as it approaches the inflexion point, rather more aggressively - all of this though, critically, without the parody or extremity of Stainers later, lesser imitators, whose work is characterized more often by arching which begins very flatly and then at about 3/4 of the distance drops off almost like a cliff towards the D-shaped channel. Even at its most experimental, Stainer's shapes remain Cremonese, with only conservative and geometrically sensible derivations.

Boom

I should have said this before, but I just realized you're hoping for a machine on which you can do it all - from coarse shaping of blade geometry to fine lapping and honing. If that is the case, then instead of the cbn grinder or the tormek, you'd be much better served in my view by a belt machine. Rather than a harbor freight special, though, you want the kind used by knife makers, where it's set up specifically for blades. You can then make or buy your own jigs for each kind of tool (or, on many you can use tormek jigs on the belt machine). The strength of a belt machine of this kind is that you can grind flat (on the platten) or hollow (on the wheel) or Japanese (convex, on the unsupported part of the belt). Then, you can swap through various grits until you've got a fine polish, the likes of which you'd get on a fine stone. For example, hard felt belts charged with low micron pastes or rouge are equivalent to a ultra fine water stone. You can write to me if you want more information about these kinds of machines.

You're aware, I assume, that the bass bar is installed not on the back, but on the belly? Perhaps you meant sound post cracks... In any case, slab backs have been in use since Andrea Amati and Zannetto, and while they can (like quartersawn) develop post cracks, good makers tend to shape slab backs differently in order to accommodate their different properties. Just use your beautiful slab back youve mentioned and leave it a little thicker where it needs the strength. Stop worrying and get on with making or you'll never improve.

Fortunately for Widhalm, nobody cares if you're "sure". The instruments continue to stand the test of time and perform for professional musicians. Just goes to show ya, someone who knows what their doing can have success regardless of whether the punters can follow along or not. I'd have though del Gesu would have made that obvious by this point.

Completely mistaken, actually. There are a bunch of jigs and fixtures, but I tend to freehand plane irons, chisels, gouges, knives, etc. You may not be familiar with the name, being new to the craft, but when the book was written the Weisshar shop was the creme de la creme of restoration west of the Mississippi.

I would second the suggestion of a cbn wheel on either a conventional grinder or better still a hand grinder. If you can get access to a copy, the hans weisshar restoration book shows plans for a fantastic hand grinder table. I'll try to attach a photo of ours. Ours here has a standard wheel, but I'm going to replace it with 80 grit cbn at the first opportunity. In my personal shop, I have a grinder I built myself (I've posted photos here before, you should be able to search). I used a DC motor for even torque curve over speed, a veritas test, and a cbn wheel. Best little grinder! I also have a viel belt machine with all the trizact belts, a leather honing belt, and jigs. Like you, I prefer to carve than sharpen, and between those grinders and my water stones, everything goes fast fast fast. Granted, decades of practice in hand sharpening is part of the package.

And you have come to that conclusion... How exactly? Regardless of how, you happen to be mistaken. In addition to myself, I am confident that there are many others who could ID this wood. However, none of us are likely to do it without being given a well lit, nicely composed photograph of the endgrain under at least 10x magnification. Why so specific? Because that's what it takes to get a professional opinion. If you're interested, you can read Hoadley's "Identifying Wood" to gain an actual understanding. Despite your excitement for ChatGPT, you don't seem to know very much about it. It's an LLM, or large language model. It is not, however, a Large Wood Model, and is incapable of identifying wood with any level of proficiency or ability until it is given appropriate data sets. How likely do you think that is? I'm not just blowing smoke. I have presented dozens of photos of wood which I know the identity of. It has failed to identify any of them correctly.

I thought the same. I've milled a lot of American sycamore, and it looks quite like these bridges. I've also milled some beech - similar but not as likely as sycamore for these.