JoeDeF

Members
  • Content Count

    127
  • Joined

  • Last visited

Everything posted by JoeDeF

  1. It is my (limited) understanding that tartini tones are created by nonlinearity. That nonlinearity could be in a mechanical object like the instrument or your ear, but I have read that air can behave in a nonlinear fashion. Difference tones don't tend to show up in measurements. As a mental model just for visualization, I think of two colored lasers being beamed into a fuzzy lens that partially outputs the mixed waves, yielding a third color. If you take a picture of the lasers with a clear lens (measurement instrument), you only get a picture of the two colors, not the mixed third one. Again, just a mental model. In pianos, I do tend to hear difference tones most loudly when there is some defect in the soundboard structure. I assume that the defect creates a more nonlinear condition. In fact, when I hear them prominently, I usually start to look for soundboard cracks, loose ribs (braces, more like a series of bass bars), the soundboard separating from the inner rim, etc. I often find such a defect, though not always...which is a very roundabout way of saying that you could inspect your violin's interior very carefully for any small gluing defects, etc. If you like it as it is, I guess you wouldn't want to "fix" them, but it would be interesting to know if they are there.
  2. Brad, you are right if one of them is reverse-threaded. Then it's essentially like a turnbuckle.
  3. That's a cool idea. Just to be clear, it'll only work if the insert's outer thread is a different (probably coarser) thread pitch than the eyelet's (and the insert's interior) thread pitch.
  4. I didn't answer earlier, Ernie, because I don't have the violin one. I do have one on/in my cello, and I find it to be very useful. Actually, I've had two. In my first one, the tube contraption came apart after a while. But they promptly replaced it with no fuss, and the new one has been fine. I definitely did miss it while getting by with the old button-style wolf eliminator from the time my first Krentz went bad till the time I got the replacement one.
  5. Thanks! Beautiful texture following the flames on the back at about 12:38!
  6. JoeDeF

    Reshaping neck

    The recipe posted here by Matthew Noykos is straightforward and works for me: https://maestronet.com/forum/index.php?/topic/324250-neck-sealer/&do=findComment&comment=511743 https://maestronet.com/forum/index.php?/topic/324250-neck-sealer/&do=findComment&comment=511791 There are some good ideas by other participants in that thread as well....
  7. Thanks for the recommendation, Peter. I did some initial reading about the concepts, and it looks like they will be very useful in a variety of contexts going far beyond shop size and layout.
  8. Why make it when there are so many jars found in attics available cheaply on eBay?
  9. JoeDeF

    doctor+ violinist=

    You can imagine how it could go jumping out by watching this (though the little bugger is well controlled in the video):
  10. It sounds like the remaining sawdust after your instrument collapses. Spalting is a web of competing fungal colonies, all of which are (or were, if the wood has been dried) munching on the wood and severely weakening it. In terms of instrument use, spalted wood is primarily found on the showy but not really structural tops of electric instruments, where the underlying (non-spalted) wood does most of the work both in resisting string pull and helping to determine acoustic impedence (controlling how much of the string's energy is absorbed by the rest of the instrument). When spalted wood is used for tops of electric instruments, it is often saturated with CA glue or a penetrating epoxy to strengthen it enough to retain its shape and integrity during the life of the instrument. Some spalted wood is soft enough that you can easily dig it out with a fingernail.
  11. I think he specialized in electrics….
  12. I would guess that the extra "ears" are in effect resonators designed to suck up and dissipate high frequencies before they get to the corpus, to mellow out the sound. Is that correct?
  13. In many cases, don't blame the maker -- blame the eBay reseller who stamped the stick!
  14. It would be good if you could figure out why your glue joint failed before trying again. Were the mating wood surfaces “perfect”? Is your glue high quality? Did you overcook your glue? Did you have the glue at a good viscosity for a permanent joint? Was the wood heated? Was the room hot enough? Did you get your clamps on quickly enough? Did your clamps draw the joint tightly? Did you let the joint fully cure before you started roughing it out? I would find an old (meaning not new or green wood) 2 x 4 (framing timber) and practice making joints on that. After you prepare nice mating surfaces and glue them, cut and/or plane the wood into slabs of near violin plate thickness, and then break them apart. If they break cleanly at the joint, your glue job isn’t good enough. If they break away from the joint, your glue job is fine. If they break right around the joint but with a significant number of fibers having pulled free from both sides, that’s probably ok (IMO).
  15. Bridge carving is a complicated area, with lots of variables, subtleties, and some "rule-of-thumb" principles that various luthiers don't exactly agree about. I'll leave it to the experts to guide you in how to improve this bridge/violin. However, I can strongly recommend the site https://www.violinbridges.co.uk/ which gives you access to pictures of and detailed measurements of thousands of bridges, many from highly esteemed luthiers/shops. I think that you have to pay a small subscription fee to see all of the measurements, but it is well worth it. You get more than a dozen accurate thickness/width measurements per bridge (shown on a diagram, so you can see where each measurement was taken), plus the weight and, of course, the maker's mark. You can learn a lot from that site. Those measurements above will give you lots of valuable info. However, you'll need to supplement the measurements with information about where and how to thickness things, the proper curved surfaces on the front (and back) of the bridge, and how to fit accurately, etc. To get you started with all of that, here are a few Maestronet threads that can help you:
  16. I'm not a bowmaker, but my opinion is that your wooden blank's grain angle is far too slanted to be used on a bow. I think that the bow may break. If I were making a bow, I would use the straightest grain I could find and then bandsaw it so that the grain was straight in two dimensions (up and down, and left and right). If it were my project, I would start over. I guess pecan can be used for archery bows, so it may work if you can find a section from which you can cut a straight-grained blank. Or, instead of pecan, you could probably find another hardwood that is more often used for violin family bows, like ipe. Ipe is heavy but strong, and the wood is used for bows. I think (but am not sure) that the grain interlocks, in which case it would resist splitting. It is now sustainably grown, and reasonably inexpensive (used for decking, etc). I'm mentioning ipe because I bought some reclaimed ipe for bowmaking. I haven't gotten to that project yet, so I can't tell you much about how it behaves under hand tools (it seems to be very tough, so you'll probably need sharp tools). I also don't know how much of an allergen the sawdust is (some tropical woods should be used with precautions to avoid skin and lung exposure). Just an idea, and there are other woods that will work as well. Best of luck with your project. And if an experienced bowmaker weighs in, please trust their judgement over mine.
  17. I have maybe a third of a quart of ACE Spar Varnish (the good stuff that Craig liked, before they changed the recipe). When I heard that Craig had passed, I went down, opened it, and tried it on a scrap of veneer. It is still good, and the little veneer scrap looks nice. I'd be happy to donate my ACE spar for this build.
  18. Please protect your health, keyboardclass. Breathe as little ebony dust as possible. Read up on the health effects of breathing "exotic" wood dust; this stuff isn't like framing pine or fir. Use cutting tools to remove as much wood as you can, then scrape/sand as necessary at the very end. Even the scraper will keep most of the ebony dust out of the air (a sharp scraper used well mostly cuts; you'll get shavings and just a little dust). But do most of the work with a plane.
  19. You can peruse many cello bridge weights at: https://www.violinbridges.co.uk/ I'm pretty sure that a subscription is required; the fee is very modest. I did subscribe and am glad that I did. The site is great for detailed measurements of almost every area of the bridge, and the pictures are also helpful in considering carving details, "final touches," etc.
  20. I know nothing about a Gianmarini, but I hope you get better soon!
  21. In cheap Chinese instruments (and similar), if the saddle is glued in stubbornly, I use a very thin razor saw (the kerf it makes is around .009"-.010") to cut carefully at the intersection of the edges of the saddle and the top. You can find inexpensive razor saws at hobby shops and the like; get the thinnest one you can find, and try to get one with little or no set (in other words, one in which the teeth don't stick out towards the sides). And be very careful to avoid sawing any deeper than the top. I line up the far edge of the saw with the edge of the bridge-facing side of the saddle, push down, and pull the saw towards me. I then lift the saw and repeat until I have reached the proper depth. The saw has a square forward edge; I do most of the cutting at the very beginning of each stroke, then use the pulling motion more to pull out the sawdust than to deepen the cut, keeping the saw square to the block. That way, the cut remains square to the ribs instead of slanting downward. A bridge knife would tend to have a wedging action due to its sharpening angle, which could start or propagate a saddle crack (the exact thing we're doing this to avoid); I wouldn't use that tool for this job. That's how I do it anyway; keep in mind that lutherie is not my occupation, so as always, I am willing to defer to the many excellent full-time luthiers here if they propose a better method.
  22. JoeDeF

    Varnish

    Sometime around two decades ago, colored lacquered saxophones began to enter the market. More than one professional sax player has told me quite insistently that the black ones sound darker. IMHO, they believe what they believe because of the familiar quirk of the human mind that causes unrelated phenomena to be conflated.
  23. The way they work is...Wait, is that the Bat insignia? Quick, Robin, to the Batmobile! Our crime fighting mission compels us to spring into action at once!