Designing a tailpiece

I have the fingerboard pretty much shaped and decided to get working on the tailpiece.
I've made a few and used store bought ones. On the shorter models I've made, store bought are always too long. Since this is a "standard" length Strad at 357 or so the store bought would work. But I have the ebony fingerboard that actually looks like wood so I figured I'd make a matching tailpiece. The first question is how to make it. You could to it empirically, and copy a bought tailpiece. But how do know it is right? I set about to design one from the ground up.

I have two tailpieces sitting around. One a cheap, black (looks like plastic, but isn't) round one, and another rosewood one with the two flat angles on it. They just picture them in the catalog, and don't name them by style, so they are just round and angled. They are both within a mm in length, around 114mm. The length is just right for this violin. The hole spacing, slots, half-round lip that sticks up (I have no idea what they call that), and the outside shape is virtually identical. It looks like the angled one may have slightly lower E and G holes. What would be the implication of that? I had to do some trig. I've figured out string angles before, but didn't get the actual angle. Coming up with those measurements brought some surprises. The D string has the steepest angle, followed by the A. The E string has the flattest angle followed by the G. Lowering the G and E strings at the tailpiece would bring them closer in relationship to the A and D in between them. Doing this the G and E strings aren't technically heading directly to the top of the saddle, but they have to go there anyway because that is where the tailpiece attaches. The A and D are directly in line to the saddle.
On a violin where the simple string angle I measured before is on the steep side... 157 degrees or a little more, having the E and G at flatter angles may be a good idea. The difference I figured between the inside and outside string was about 2.5 degrees. That's more than the difference between models. The 42mm radius on the black tailpiece doesn't seem like it would work at all. That one would flatten the outer two strings over 2 degrees more. Maybe I'm on the wrong track. Maybe I'm just plain wrong. Oh well. I'll make up my "experimental" tailpiece. If it doesn't work, there's always store bought.

Odds and ends

The photo is of our backyard last fall.
I've been doing some things, but they don't look like much. I have the back area tuned. Ended up with 3rds, 5th, minor7th and an octave, just like it's supposed to. Of course sometimes it takes a few listens to figure out what you got. It sounds like D when you tap it, but it rings at E. Go figure. I thought they would be the same. Ha! I just checked and 285, or around D is one of the prominent modes on the free plate, maybe mode 4? I took it off the fixture to check it's stiffness. It's 4g lighter and it lost about 4hrz, so the stiffness is still around where everyone says it should be. Everyone? Isn't that what your kids say..."But EVERYONE does that." Feels really stiff to me. I thought these things were supposed to move. I'm tuning the belly now. It seems to have C# as the fundamental, that's a semi tone lower. Just about what EVERYBODY says it should be. I'm sure when I glued it on the ribs it rang at over 360, 272 is a lot lower than that. Maybe that is mode 4 as well. After I glue the back on I'll pop the belly off and give it a check. I'm still learning so I need to see what I actually did, to see where I'm going.

So the numbers are coming out close to where they should be according to everybody. It is wood shaped like a violin body so that isn't too surprising. What is surprising is how a great violin can be just slightly different than a so so, or bad violin. There is no way to control all of the parameters. The belly, the back, the ribs, the neck, the bridge, the soundpost, the fingerboard, the strings. Any difference, any variance, and the result is different. There are more things going on than you can keep track of. The world is the same way. The snow just melted and you can finally see the ground. What is amazing is that under the snow plants were growing. Daffodils (deer eat tulips), mums, and other hardy perennials are already pushing out of the ground. Things going on that you don't see. In your life things go on underneath, that aren't seen by others or even yourself. The things going on underneath have great effect on what comes out on the outside. Fill the inside with God's love and the outside will be beautiful.

Wrong way to make a fixture

Well the fingerboard holder didn't work. It may have worked if I made it out of maple, and not spruce! The soft wood just squishes and is useless. So I just did it the old way. Rough it out with a 9" plane, then get the 42mm radius set with a wooden plane I made up. I finish it up with my favorite scraper, a plane blade, and the blade out of the wooden plane. I could probably keep the blade in the wooden plane, but it came loose, so I left it out. I'm a scraper guy. Some are file guys, plane guys, sandpaper guys. I'm a scraper guy. The blank is still big. I ran into an aberration in this blank. Not as bad as the last blank I scrapped, but annoying. Most of it may disappear, but some will have to be hidden.
I have been playing around trigging out different violin sting angles and neck sets. See, math is fun! It started after my Ole Bull fingerboard moved down, and the belly moved up. Turns out the dryer vent was loose, and the instrument was absorbing the excess moisture. People on maestronet.com were suggesting some things and some said new instruments move. The only one I've seen move is the Montagnana with the outrageous arch. It bulged up some in the upper and lower bouts. Some said they set the fingerboard projection higher, say 27mm, in anticipation that it will drop after being strung up for a while. So I did some calculations and came up with this:




On a baroque Amati, they would have a straight neck, put whatever bridge height they felt proper, and fabricate a fingerboard to fit underneath. Later, they started morising the neck and tipping it back. I wonder if they did it to make fingerboard replacements easier, and then found players liked the thinner angled neck. Anyway, the change didn't really change the string angle much. The models arch height, length and stop makes more of a difference, and then it still is not that much. The included angles run between 157 to 159 degrees. The modern instruments have constraints built into the formula so each projection (marked elev) will only give a small range of string angle/neck angle that will give the proper (6-6.5mm) neck step. The shorter instrument would be a Bergonzi or Guadagnini and the Maggini is actually a model SMALLER than the original. One thing of note; the baroque instrument would have about the same string angle, but with the shorter neck they would also have a shorter string length(except the Maggini). The tension on the strings would be lighter, even though the string angles are the same as modern instruments. I believe this is all correct, but I could be wrong. Let me know. Don't know how I got this blue and underlined!

Slow week

I didn't accomplish much this week. I sawed the sides of the fingerboard (10 minutes max, counting the planing), and started making a fixture to hold the board while planing the radius on. I used to try to hold it on the ends, but it is just too hard to do that way. A fixture is needed. It's a very simple thing.I have all the pieces cut out. I still need to cut 5mm deep grooves, 5mm wide (the width I made the thin strips), and glue them into the base. After planing the strips so they are 5mm proud of the base I'll saw it in half lengthwise and voilà, a fingerboard holding fixture. I'm making one for viola as well. It WILL be done this week, and I'll show the results. I spent more time drawing up plans for a Guadagnini viola and violin. I have the Strad poster for the viola, but even with that a working drawing is needed. The violin is from photos in the book Masterpieces of Italian Violin Making, by David Rattray. Cool stuff in there. I worked them out to scale on a standard sheet of paper, but drawing them full size exposes all the flaws! I think they are set now. The violin has fairly tall arching, almost as high as the viola. It is also on the small size, as violins go, much like most del Gesu instruments. I thought it might make a nice companion to a small del Gesu model. I picture myself making violins, violas and cellos that are just a bit different, but great instruments. Maybe a couple larger violins, A Maggini and a long pattern Strad. An Amati and something else in the middle, and the del Gesu and Guad on the short side. But Guadagnini is supposed to have made excellent cellos, so maybe just make Guads? Gagilanos look cool too. Any thoughts anyone? I put the two patterns on my lightbox and the Guadagnini is almost identical in form to the Ole Bull del Gesu. I needed to re-do my viola plan after finding some things out while doing the violin form. I'm happy with the way it came out. Now I can make up a mold for the viola. I have a back roughed in for it, you can see from the photo it is VERY rough. I had to cut a gum pocket off the upper bout and glue a wing on. I still need a neck block and some rib stock. I usually have buy a board big enough to saw out ribs and necks, but this one and another were just big enough for backs. Anyone have some figured cherry for ribs and a neck? I thought about 1/16" veneers, but haven't been able to find any figured cherry. Also a lot of the stuff is 4' x 8'! Maybe I'll need a trip to the Woodcraft store.

Starting on the fingerboard

I'm still doing some tuning on the back and belly. Tuning seems to be the king of thing you do for an hour or so, then do something else. Something else turned into a few other things: saw out the fingerboard blank and plane it some, figure out the outline of a Guadagnini violin, and then take another go at the Guadagnini viola outline after gaining some insight after cracking the violin code (I think). They are different, the violin is WAY slimmer, I call the viola "Fat Boy", but that's not politically correct. Good thing I'm not into politics. I think Guadangnini went about designing both instruments the same way, but looking for different things.
The thing I'll talk about here is the fingerboard. Most people just buy a blank. Again I'm not most people. I like to go to the wood store and tap on a bunch of wood blanks and hear how they sound. I did that the other week and picked up a chunk of ebony and another of the Honduran Rosewood. I can't help it, the rosewood just sounds better. Since this is supposed to be a straight up instrument, the ebony is the pick. Right now it is planed top an bottom fairly flat. I put tape on it to mark the long cuts. The small end is about 9mm thick and the wide end is about 13mm thick. This is because of the radius on the top. Do the trig, it doesn't hurt. At first glance fingerboards seem simple enough. That's what I thought. Then one day a few years ago someone wrote on maestronet what a complex engineering feat they were. What? It's just a board, angled on each side about 2 degrees, with a 42mm radius on the top, a 5.5mm flat along the edge, undercut underneath from almost where it cantilevers over the end of the neck, has a slight radius along the length on the top giving a .5 to 1mm relief about 2/3 of the way down, and a slight radius on the sides to keep the 5.5mm flat the same height in spite of the relief on the top. The strings can't buzz anywhere along the length when stopped by your finger, and at the same time the pressure should feel the same, from string to string and from top to bottom. Simple. The pressure part is what I'm just learning about. A straight board will not buzz, if the string height at the end of the board is not too low. Then why put the relief in? Feel. If you pull back on a long bow, you pull in the middle. If you pull an inch above the middle it will feel harder, even though the pressure on the string is the same. Move your hand even closer to the bow and the pressure seems to go up even more. The same goes for pushing the strings down on the fingerboard. In the middle of the length, an octave up, the sting will feel it's lightest. Up or down the fingerboard from there and the string feels tighter. You can make the fingerboard so the clearance at the end is less than normal and the undercutting is a little more than normal and the feel will be almost the same the entire length. Most fingerboards aren't done this way, I don't know why. May be tradition, may be projection, may be something I haven't thought of. Anyway, a fingerboard is more than it seems, but not a thing to worry about. But then again I don't worry about anything.

F holes are cut

Well the f holes are in so it's time to finish tuning the belly up.They aren't finished, but in the tuning process they will be, along with the fluting.I found a really simple and effective way to cut the terminal holes. I chucked a brass rod in my lathe, turned it down to just under 10mm about 10mm back, drilled a 1/8 hole in it (same size I drilled as my pilot holes), then relieved the inside about 8mm deep forming a tube shape. A few slashes with a thin file and I had teeth on it. Using the 1/8 drill as a guide the tool worked great, cut even better than the other ones did.

I didn't have as much luck cutting the actual shape though. All the other violins I made out of Englemann spruce. This one is Adirondack spruce, or red spruce. They are both spruce but different animals. Red spruce is stiffer, cuts in long fibrous pieces, has much harder growth lines, and is just not as easy to cut. I usually take a couple of wedge shaped chunks out of the main length of the hole and it is through. Then I just took full depth cuts with the knife well inside the line until the hole was through the entire length. Then it's just a matter of opening the width up. I couldn't do it that way on the red spruce. I couldn't get my knives to poke through it at all! It took a while but I finally broke though, and in the process chipping out some parts on the inside. I'll have to glue them back in. Even cutting the sides to width, using a slicing or paring cut wan't as much fun. The blade was twisting and bending. The knife I was using is just a #11 X-acto knife. It just isn't stiff enough. I asked for suggestions on maestronet.com and Michael Darnton says he uses an 8mm laminated Japanese knife. Like E. F. Hutton, when Michael Darnton talks..... It will be ordered. I have some laminated Japanese gouges and chisels and they are really nice. I'll have to make a handle, but that should be fun. My wife says I can't just use anything the way it comes, so it's a good thing I have to do something to finish it.

Cutting the terminal holes

I started cutting the f holes today. The first step is drilling the terminal holes. If you've ever drill holes in wood you know what happens when you break through...you get some chip out. There is neat way around that, drill a smaller hole and enlarge it with a piloted cutter. You can buy a really nice set of these, in .5mm steps, for violin/viola or cello for $100 and change. Or if you're a machinist, have a mini lathe in the basement, and have some old indicator holder pieces you can make your own. Guess which way I did it. Mine probably don't work as well as the store bought, but the price was right. The way it works is this: You drill a hole in the center of where the terminal will be, the same size as the pilot shaft on the tool you made, or bought. Then you slip on (screw on in my case) the right size bit for the whole you're cutting. Slip the pilot into the hole you drilled and then start turning the bit into the wood. It should cut a perfectly round hole exactly the size it was made. Here's the part that makes it a great idea. Only cut the bigger hole half way through. The pull out the tool, slip the pilot in from the back side and continue drilling the big hole from the inside. When the two holes connect a plug will fall out and your hole is done. Continue on for the other three holes, being sure to use the right tip for the hole you are doing. It would be hard to hide a 8.7mm UPPER terminal hole! I have four sizes: 6.5mm, 6.7mm, 8.1mm and 8.75mm. Don't exactly remember what I made them for, but I'm guessing 2 were for the Ole Bull, and the other two were for whatever model I was working on when I came up with the idea of making the tool. The "Titan" model I'm going for has 6.8mm and 9.6mm, so I don't have the right combo. Maybe I'll scrounge around and see if I can find something to make a 9.6 out of. If I remember correctly, 8.75 was the diameter of the fittings I had, so it was the largest size I could make out of them. If you are making a Guadagnini model, with teardrop holes you can disregard this post. By the way I think the teardrop Guads are pretty cool looking.