Ken_N

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About Ken_N

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  • Birthday 06/20/1955

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  • Gender
    Male
  • Location
    Goodrich, Michigan
  • Interests
    Violin making. Art (just got some oil paints, been doing water color). Driving the back roads. Music, especially orchestral and Christian rock.

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  1. I don't know about a cello. He said viol, and I googled viol and found this, an extraordinary beast about the same size as a cello: https://www.metmuseum.org/art/collection/search/503349
  2. Neck Overstand

    With the high arch I was just trying to get down to about a 158 degree string angle without a huge overstand, an 8 mm tall saddle, and a 29 mm bridge. I changed the way I did the long arch on the second one. It has a much more complex sound. The first is very clear and easy to play. Different woods on all of them. Completely different sound. I like them both, but they are different. Yes, what you are saying is absolutely true. All I am adding is that the nature of the tall bridge/flat arch has the added benefit of the greater leverage. So they work together. The high arch, being stronger, has the low bridge/arch leverage working against it. I have tried to set up all of mine with an afterlength that is 6:1 or at a fifth. But I also try to get them so that the tailpiece is 2 Xs that. And lately I've made the tailpiece to balance in the middle. Hoping for a 2:1 rocking on the saddle side of the strings? The Montagnana's have a longer stop, so the afterlength and tailpiece is made a semitone short, a minor sixth. Does it help? I don't know. That's the only way I set it up. A big viola has a shorter stop, so I did that one to a flat fifth. It sounds good, I guess. I just found our yesterday before I went into work that the MVA is having a double meeting in Ann Arbor with Joseph Curtin. The second part will be at UM music school titled 'Learning to Hear the Violin.' That might help me figuring out if complex, woody, flutelike, or pure sounds are good. The first is on set-up and acoustic research. I can't even get audacity to work.
  3. Neck Overstand

    Another thing I use when thinking of different models is what Joseph Curtin wrote somewhere about bridges. Something about rocking angle and leverage. So I figure out the bridge/arch ratio. A high bridge/arch ratio, like on a 14.5 mm del Gesu with a 34 mm bridge has a substantial amount of leverage, and the belly can be much thicker. A Montagnana with a 19 mm arch and a 32 mm bridge doesn't have that advantage, and must be made with more flexibility. Of course they will have a different sound and feel. That's a good thing, isn't it? You want them all the same? The del Gesu, even with the taller bridge might have a flatter string angle. You could make them the same. You could probably play around and make the overstands the same if you wanted to. All kinds of variables. Shorter stops, and longer stops change the angle ratio between the neck and the tailpiece.
  4. Neck Overstand

    I go about it backwards. Surprise! I figure out the angle to the saddle first, because it isn't as variable. Pick a number for the saddle, 5.5 mm? and subtract it from the arch height (A) and a bridge height guess 32? (27 projection + 5 for string clearance. That gives some angle in the teens, maybe 14 degrees. If you are looking for 158 you want 8 more degrees. Go backward, and take the inverse tan of your horizontal plane stringlength. 325? That will give you a number for the height. Subtract that, and you will find the location of the top of the nut at your perfect angle. Now you have to check to see if it will work. The top of the nut doesn't help you any. Neither does 8 degrees. You need the neck angle. Take 8 degrees and subtract .85 degrees for the string clearance over the fingerboard, and .85 degrees for the taper of the fingerboard. Those might not be exact numbers, but they are close. Do the math if you want them closer. If you are figuring out a viola, the numbers will be higher. We end up with 6.3 degrees for the neck angle. Now subtract 7 mm or so, (the nut) from the number you had for the top of the nut. Let's say the number was 5.5 mm, now the number is -1.5 mm. This is the top of the neck at the nut, 1.5 mm below the plane of the belly. We are now ready to see if the overstand is in the ballpark. Multiply tan 6.3 by the length of the neck. I use about 5 more, or 135 on a standard neck, which happily divides the fingerboard in half too. That gives us, in this example 13.4 mm. That is the total to the block. But not yet! The end of the neck is at -1.5 so the number is 11.9 This number is far more useful to builders than the measurement to the top of the plate, but that is what people SEE, so subtract 4.5 and we get an overstand of 7.4. In this example we'd have to adjust a few things if we feel it is too high. Tapered ribs complicate things. If you have them, you have more figuring to do at the start to define the points better. Keep the plane at the top block at zero, and figure out where the saddle would be, and how much to add or subtract to the arch height. It's not hard, just tricky. Drawing it out helps. If you did the same models all the time, you don't have to do it very often, only if starting something new. Or you forget to write it down, or where you wrote it down. I've done that.
  5. Mold Material

    I always glue my blocks on with little blocks glued to the face of the mold. I never had any luck gluing to the edges. They would always fall off. Gluing with blocks is very stable, and easy to break them free when done. Hence the veneer top and bottom.
  6. Neck Overstand

    I don't quite understand it, but a physics site said that 50 pounds of string force makes about 20 pounds of force on the belly at 158 degrees. The change of force with a plus or minus 1 degree string angle couldn't be much; could it? Half a pound either way? Different strings could make more of a difference. 20 pounds isn't very much force.
  7. Torbjorn Zethelius's note on arching heights.

    I could probably give that one another go. The one I made was plagued with problems. The belly wood is very, very prone to cracking. The neck got black spots of mold or something all over it. The varnish was having problems, but when I finally got it better, the belly was cracking and the spots started. Like it was possessed. For the first ones I used cheap wood for the back and neck that I found locally. I haven't found belly wood anywhere local, so I've always bought that from dealers. I still like cheap nice wood! I so sometimes make varnish tests, but I'm more likely to just jump in with both feet. I have no fear. I'm not one to follow the rules. My wife says my motto should be Why Be Normal? The arching on that one looks nice. I have to do something with the long arch. Torbjorn pointed out to me that they need to start rising right from the purfling; and the back long arch doesn't.
  8. Mold Material

    Funny you should say that. I made a few MDF forms before I bought some vinyl? clad pressboard shelving for $2 at Menards. Actually, I like the MDF better, but it IS extremely dusty. I was going to throw a couple out, don't know what I was thinking when I made them, but decided to slice and dice them, and glue on extra pieces to make them right, and simply butt the edges together, and bolt them together with two pieces of hardboard. I'm even going to put some veneer on them just to make them pretty.
  9. Neck Overstand

    I guess it's just flying over my head. The tension on the string would not increase by making the block twice as high? It sure seems like it would. You're saying that as the string is pulled back, the tension of the string stays the same, but the energy is transformed to the arrow? Really? Then why does it get harder to pull back. This just isn't making any sense. I guess you guys are right, but it still makes no sense at all. If i could keep the strings the same, remove the bridge, put a lower one in, there would of course be lower tension. But the notes would be lower as well. They would still have to be tuned up to the same tension as before to be at the same pitch. I just don't get it yet.
  10. Neck Overstand

    But no matter how tall the piece of wood is; at A 440 it will still have the same tension. Will it not?
  11. Neck Overstand

    I have never understood the notion that the string angle would change the pressure on the belly. It just makes no sense. If you had a long bow that was three feet long and when you pulled it back to a pressure of say 70 pounds. Let's say the angle of the strings is 158 degrees. Everytime you pulled it back to 70 pounds, say A 440; it would be at 158 degrees. If you pull it to 159 degrees, it will have let's say, 68 pounds. 157 might give 72 pounds. This is the problem. This example changes the A 440. At 159 degrees it is only A 430. At 157 degrees it is A 450. A 440 has to stay the same. If you have an instrument tuned to A 440, it HAS to have the same tension whether it has a160 degree string angle or a 154 degree string angle. How can it possibly change? String angles are determined by bow clearance, and neck placement. A viola needs a higher bridge than a violin if it is wider. A cello needs to be much higher than both of them. The angle cannot have any effect on the pressure. The tension must be at the proper pitch. Thicker, stiffer strings will put considerably more tension on the bridge. A longer string length will put more tension on the bridge. Stiff stings with a shorter string length might put the same pressure on a bridge as light strings on a long string length. At the same string length the stiff strings will produce more pressure. Height and string angle doesn't matter. Am I missing something?
  12. Torbjorn Zethelius's note on arching heights.

    Torbjörn used to have links to the articles right on his name and photo here. They are gone. The Strad may have held them hostage? I can't get on them without a subscription. Everyone wants to make a buck. It is really quite simple. Each maker's model may need a different approach. Careful examination of the archings is needed if a copy is desired. Figure out what you need to do for the long arch by drawing out the inside long arch from the thicknesses. Then figure out how far in from the end the cross arches need to be. Then do it. Some may have a lot of recurve, especially in the bouts. You can even draw one up using curdate cycloids on the outside, and figuring out your own long arches. Oh, you are a new member. Sorry, it may not be that intuitive! You have more questions than someone who has made instruments before. I'm not saying it can't be done. I've made all of mine that way. Welcome. Beware, It is addictive. Check out my blog https://violinsbyken.blogspot.com/ Go back a ways. Making the Strad. If you have questions. Ask. You can PM me, (for some reason comments don't seem to work on the blog) Or maybe I'll do something on contemporary maker's bench. A how to make one inside out. Don't know if anyone would want to see that, most think it is akin to blasphemy.
  13. Sjöbergs workbenches

    The holes in the vise for the plastic post things, dogs? are a foot apart. Both of them are the same. The vises themselves have a bit of play so they will clamp things that aren't particularly parallel. I think that's a good thing. I like mine. It's about 53" X 20" and I got the cabinet underneath for free on sale at Woodcraft. One would think that the cabinet and drawers would help with the clutter on the bench. I love the drawers, and cabinet, and they are neatly arranged. The top is still cluttered. I like to believe that it is because I work in short bursts, and never clean up, except the chips on the floor. I fantasize that when I retire, the bench will always be clean, and the tools back in their place. Right? I have glued a cello back and belly up on it, and had no problem. It was a nice size for carving too; I could work on both sides by clamping it lengthwise with the end vise. I never finished it because the back arch is very low because the blank was thin, and my saw cut was terrible. I actually pulled the back apart with a heat gun and water, and re-glued it on a taper to raise it up, and was in the process of doubling the edges to maybe make it work. I did tap them the other day when I moved my wood shelf around. Man; they really sound cool. I mean really. So many overtones. As far as being solid; it doesn't wiggle. It will sometimes move on the tile floor, but FAR less than my B&D Workmate did! If I had a shop, I'd anchor it. Sandbags on the spreaders? Sticky tape on the feet? How heavy would a bench have to be to not move? And then, how would you move it?
  14. If you want to - really want to...

    Maybe a great technique for giant tenor violas? Better sound projection?
  15. If you want to - really want to...

    Quite a different technique. Most of the time it appears that the strings are only stopped with the finger, and never reach the fingerboard. The thumb stops down to the fingerboard, and a few times he does play vibrato with the fingers, obviously on the fingerboard, but usually they don't. I don't play; do other violinists do that too? Is it just me, or is that bow HUGE? Cool.