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.

Scrapers, smoothing everything up

I've been tuning up the belly. Some of the tuning is done on the outside and some on the inside. I cut the taper on the sides of the bass bar with a chisel. It's still too tall. By the way the glue/clamp setup worked very well, but so did the rub joints...I think. Almost all of the work I do once the main shape is carved is done with scrapers. I don't think I've said much about scrapers. Scrapers are just strips of metal with a smooth, sharp edge that cuts the wood like a very high angle plane. I like to use ready made stiff ones, like plane blades and gouges. Almost the whole of the inside is done with the rounded plane blade, with the recurve done almost entirely with the 1" gouge. Since the inside is entirely concave there isn't much use for a flat edge scraper. Both are very stiff, with a 20-22 degree edge ground on them. I do use the big gouge sometimes on the recurve to be sure everything is consistent. On the outside the straight plane blade is the workhorse, doing just about everything. I also use the rounded plane blade in the recurve area. The small scrapers, made out of shim stock, work right around the purfling. The tight one for the c-bouts, a flatter one for the u-bout, and the flattest for the l-bout. The other end on one of the shims is used on scrolls.

The scrapers blend in the divots made by the gouges. Many violin makers use sets of small brass planes with rounded soles to rough things in a little faster and smoother. I haven't bought a set of these yet. But I did see a cheap (inexpensive?) set from China online for $50 ($75 with shipping) on Ebay that might be worth looking into. For a machinist I am not a big tool nut, and outside of work I don't even use power tools. Smoothing in the curves is best done without a lot of light, but with it coming from the right angle. The scrapers are swung in long arcs, and the angle may have to shift as it goes along. The goal is to make every curve blend into the next.

Gluing the bass bar

Posting early today...it's a SNOW DAY! Doesn't mean it's ALL fun and games, in half an hour I shoveled 15' of our driveway, still more than a hundred to go. Now on to the business at hand, gluing bass bars. I've never quite understood why makers throw so many camps on when gluing the bass bar. They will glue the center seam of the belly with a rub joint, and no clamps at all, but gluing the bass bar requires as many as they can fit in. My confession...all the bass bars I've done before this one are just rub joints. Can someone out there tell me why all the clamps are needed? No answer? Well, with my new assembly/tuning board I too can glue my bass bar on with clamps..round ones. Here's how I do it: I rough the height and shape of the bar done so it is still too tall, but not straight and fit it to the belly. When it is ready to glue I clamp a stick to the assembly board and measure from the stick to the bass bar. I cut an old wooden hanger post into seven dowels, (only used 6) and cut up 7 blocks to make into wedges the length left from the stick to the bar. I used the dowels to hold the wedges in place while gluing them to the stick. Once dry I put glue on the bass bar and belly, rub in place, and then rolled the dowels in place to hold it in position. Works really well. One point to remember. The dowels are just holding it in place. Don't put a lot of pressure on it, only enough to keep the dowel from falling down. I'll check it out tomorrow and see how it came out. The bottom of the photo shows my high tech glue warmer. A clay cup inside of another clay cup. Fill 3/4 up with water (both cups), and toss in the microwave for 2 minutes. I'm sure it is the same set up Stradivari used, but he had the old microwaves with low power, maybe was even faster to just use a kettle. Well loafed around for an hour and a half, time for more shoveling.