If the interval between the open note and the octave (supposedly exactly 1/2 of the vibrating string length) is smaller than it should be (the octave is flat) then you have to make the interval longer. You can do this by moving the tangent until it touches at the halfway point of the string, or you can lengthen the string until the arrangement allows the tangent to touch in the middle of the string without adjusting the tangent. Since you really shouldn't adjust the bridge, the only place you have to adjust is the nut.
The benefit of understanding this is that if you know the instrument key spacing was set up correctly, then nut placement becomes easy. You simply measure the bridge-octave tangent point length, then measure from the tangent point to toward the peghead and place the nut at exactly the same length. Since no strings are perfect, you may still have a little adjustment to do, but you will be near spot-on. Chris *********** REPLY SEPARATOR *********** On 12/29/2008 at 6:43 AM Craig Currier wrote: Greetings, all I am an amateur luthier in the final throes of setting up an 18th century French guitar shaped Bassot HG (one of only 3 we know to exist in the entire world) I have been restoring for my wife Barbara to play. I will have a few days off after the New Year and hope to be able to deliver her a playable instrument soon. A few questions: 1: How much does any uncottoned string actually touch the wheel? ie, does it skim the wheel barely touching upon it and producing sound? Does it ride ever so slightly above the wheel (perhaps the thickness or a zig zag paper) but no sound is produced? Does it ride upon the wheel so heavily that sound is produced and (possibly) the vibrating length of the string is shortened from bridge to the edge of the wheel? Or what? 2: Barbara's notes from an OTW class about HG setup and maintenance say: If the octave (ie the open g of a chanterelle against the octave g key with the tangents dead perpendicular to the string) is flat the nut should be moved toward the head. If it is sharp the nut should be moved toward the bridge. I'm just a guitar and banjo guy, but this doesn't make sense. Ie, lengthen the string to make it higher in pitch, shorten it to make it lower in pitch? HG musical physicists, can you make sense of this? 3: How much (if any) looseness is permissible in the keybox as the keys go though? We have at hand, among other sources, the Destrem/Heidemannn book, the Muskett method book and the new Neil Brook video. Any and all answers appreciated on or off list. Thanks in advance for any assistance you can offer. Craig Currier [email protected] "The entertainment business is a cruel and shallow money trench, a long plastic hallway where thieves and pimps run free, and good men die like dogs. There's also a negative side." -Hunter S. Thompson --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "hurdygurdy" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hurdygurdy The rules of posting, courtesy, and other list information may be found at http://hurdygurdy.com/mailinglist/index.htm. -~----------~----~----~----~------~----~------~--~---
