Don Noon

For M2, the central part of the plate is not active, so you need to have the speaker someplace effective... probably near the upper or lower block areas.

Visually, there's no way that your "10mm" mark is 14.3 times as thick as the "0.7mm" marking. I'm guessing you really have 3, 4, 5, 7, and 10 mm. Yes, a taper gage is a handy tool for setting gap dimension.

You just use the taper gage to check the distance between the drill bit and the leather head.

If you think about it, that indicates that the peg is out of round. If the peg is round, it will turn evenly in a square hole or whatever. I would guess that the pegs were made of wood that is not well seasoned. A lathe will cut round... unless you use a dull bit.

Some PC board carbide mini drills. A home made taper gage, sawed on a bandsaw, planed, and marked using a caliper. For roughing. You could mark 1/10 mm or make a shallower taper for more precision. A couple of step gages made of rosewood, milled on my CNC router table. They're 2 separate gages. Or you could just buy this on Amazon, or similar anywhere:

Nope, it isn't. Most of us use the metric system anyway for violin stuff, except sometimes inches is used for describing viola length (probably just a smaller number that's easier to remember than cm).

Two suggestions: Use a smaller drill. 1 - 2 mm is enough to see, and reduces the chance of grabbing or chipping. On my first viola, I had to patch a through-hole when the drill sucked up the plate. I now use a carbide PC board drill... they're cheap and you never have to sharpen them. You can't go too deep with them, but redrilling and carving in 3 mm steps isn't too much of a pain. The pressure is lower too, which is nice to avoid dimpling the good side (I use a steel ball with no pad, no problems). Get or make a tapered thickness gage. It's easier and more precise than a ruler. You can make one by cutting a thin tapered piece of wood, and marking it using a caliper.

You don't need chladni patterns to tell you that.

Burr size is mostly related to what I want to do: big burr on a thick scraper if I want to hog off material, and smaller burr on a thinner scraper for fine work. Lately I have preferred grinding to 90 degrees on my diamond disc grinder, mostly because any angle tend to be unstable, with the scraper tending to jump suddenly.

That was in his "tonal copies" era, trying to match modal frequencies of old Cremonese instruments. Back then, he was one of the leaders in analyzing and adjusting modes of an assembled violin... which was limited to signature modes and perhaps a few more above that, but below 1 kHz. Looking at the list of publications on his website, he has apparently gone silent for more than 20 years. It is my understanding that he abandoned the "tonal copies" idea, and it is my guess that he realized that the stuff under 1 kHz isn't super-critical to the tonal quality of the violin, and the stuff over 1 kHz isn't analyzable or controllable in any scientific way, other than by experience and trial-and-error. So he just concentrated on making violins.

From what I've read and my own testing, linseed oil is not particularly waterproof. Sweaty hands can turn it to goo, unless I'm missing something. I'm still a fan of tung oil, as I posted 11 years ago on page 1, although I have made some modifications. Terpene resin in solvent adds some nice color and seals the wood initially, then tung oil, rubbed off as much as possible. Then wipe with a rag with a bit of talcum powder on it. Looks nice, reasonably waterproof, and slippery. If the wood is dark to start with (mine is torrefied), I might skip the terpene and just go with more light tung coats.

The back on the violin I'm trying to get finished was 93.8 g. M5 was 400 Hz. 358 mm back length. An outlier, even for me.

Marty, your post seems to imply that Schleske does this tuning as part of his normal making process, which is not true. It is an experiment (30 years ago!) to look at how taptones affect the assembled instrument. Please note his conclusion at the end of this experiment, which I mostly* agree with: *I think it is well-established that some free plate taptones have a weak correlation to the B mode frequencies of the assembled violin... which isn't of much importance anyway. There is zero evidence that I am aware of to correlate taptones to tonal featured in the more important higher frequencies (excepting perhaps wildly abnormal taptones might possibly be shown to result in somewhat abnormal tonal features).

HA! Now THIS is a lifetime supply of varnish (except none of them are perfect, so I need something else): Lesson learned: it's fairly easy and addictive to cook up varnish. It's a lot harder to get rid of it. (By the way, 5 large jars in the photo are from when I consolidated 21 different varnishes in one big cookout to simplify my inventory.)

It is OK to believe in taptones... but another thing to worship them I too take into consideration weight, M5, and thickness in deciding where to stop. With wood that's different (they all are, to some degree), you can't make everything the same. At least we can hope for something still good, even though not the same as last time. Or maybe it will be better; you never know.