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For the lovers of the flea.
Latest Activity: Feb 17
Started by Paul Walters Nov 20, 2013.
Started by susi Lawson. Last reply by susi Lawson May 19, 2013.
Started by Greg Nelson. Last reply by T Willi Dec 30, 2012.
Dear lovers of the flea,
This link will take you to a different approach on the Uke (or cavaquinho):
Hope you like it!
One more thought. Perhaps the nut is too far from the first fret. You can use a fret calculator to discover the distance that the first fret should be from the nut. If the first fret is too far from the nut then all notes would be sharp.
If that is accurate check that the strings are not "launching" off the nut before they reach the face of the nut that abuts the fret board. The string should sit solidly on the nut all the way to the edge.
Like I said before, there are many possible reasons for this effect.
Thank you Luis, and Greg, for your expert advice. When I have time I will try your idea. If it does not work perfectly, or if I make a mistake, no harm done, since as I said it is a very inexpensive instrument. If nothing else, I have learned a lot from both of you.
Not only this thread flows in a foreign language (to me, of course), but also you use imperial measures, and I need to convert into metric ones before I can understand what's going on! Pure fun! I'm loving it!
Now, Paul, be assured: Your Uke WILL play in tune, ringing like bells. But, first, let's recapitulate:
The upper edge of the saddle is about 1/8" above the bridge. That's higher than what I estimated (1.5 or 2mm). GREG WAS RIGHT, frontal pictures may induce error!
IF the saddle was higher, then, lowering it could flatten the pitch of fretted notes, thus solving, or minimizing, the problem; But it is now clear that if you lower the saddle the strings will probably buzz - 2mm action at the 12th fret is very near the minimum admissible.
SO, the only alternative is to MOVE THE SADDLE BACKWARDS. I mean, move THE SADDLE, not the bridge. Like Greg said, the removing the BRIDGE and moving it backwards could catastrophic. It's always difficult and tricky to remove a bridge. I never considered that, I'm talking of moving the saddle without moving the bridge. How ?
The classic solution is to remove the saddle, then make the slot wider, thus allowing the saddle to move backwards, then place a small piece of hardwood at the frontal side of the saddle to make sure it will stay in place. But this requires expensive tools and long-trained hands.
There's another way: remove the saddle and fill the bridge with some piece of hardwood, leaving it flush to the bridge surface. If you cant remove the saddle you may as well file it flush to the surface of the bridge (a nail file will do the job if you go slowly and with great care. Take it easy!
Once you get a smooth surface, you only need a new saddle, about 1/8" thick (that is, as high as the emerging part of the original bridge) and simply place it behind the slot, spotting the exact position by trials and errors. It must rest on the bridge in perfect contact with the bridge surface (ideally, both should be dead straight to make a perfect contact). The tension of the strings may be enough to keep it in place. If the saddle tends to slide frontwards, a drop of glue will fix that.
Will this solve the intonation problem? Yes.
Is there a chance that the instrument may lose a little volume and tone? Yes, but, if the inferior face of the new saddle fits properly the surface of the bridge, that will minimize the problem (the slot sides also play a role in transmitting the string vibration to the top, but the major role is played by the inferior face).
This won't require sophisticated tools, nor great skills, and will probably leave your instrument with accurate intonation and reasonable sound, without significant esthetic damage.
I assume the frets are accurately positioned because nowadays 99% of the instruments, namely industrial instruments made in third world countries to take advantage of low salaries, have accurate fretting; inaccurate fret positioning is more frequent in cheap hand-made instruments. Bridge positioning, however, requires great care and is time-consuming. A wrong bridge positioning is thus more likely...
A high nut can sharpen the first fretted notes but from, say, 4th or 5th fret on, the inaccuracy caused by a high nut tends to minimize or disappear. Since you said that ALL the fretted notes were sharp, I tended to believe that the problem was the saddle positioning.
Hope this helps... I'm enjoying it!
Well then, the action seems within reasonable tolerance so you may need to lengthen the compensation by moving the saddle. Without some confidence and competence in wood working you should seek out a luthier in your area that can deal with this. I would be happy to oblige but the shipping from Canada to California and back alone would be a non starter.
The distance from nut to 12th fret is 6 3/4 ", the distance from 12th fret to saddle is exactly 3/32 longer. As far as I can tell, the action at the first fret is 1 mm, at the 12th fret is 2 mm.
The height above the bridge doesn't tell us much. What is the action height at the first fret? Do you have to press a significant distance to fret the note? Same question at the 12th. Measure from top of fret to bottom of string if you can.
Also, can you measure the distance from nut to 12th and then from 12th to saddle? The distance from 12th to saddle should be about 3/32" longer than the nut to 12th.
Hi Greg and Luis
The saddle is about 1/8 " above the bridge. I have almost no woodworking skills at all. I have great respect for the skills of instrument builders and repair people.
Agreed, but I think you will also agree that removing and moving the bridge is even more complicated! We will also need to know Paul's comfort level, experience and tooling before letting him loose on this.
Luthiers who do repair work have a tougher job than most people think.
The idea of using the smooth part of a metal drill as an experimental saddle is a good one. However, to make the slot wider is a delicate operation requiring adequate tools and great expertise...
At this point, it would be of great help if Paul could tell us how high above the bridge is the saddle...
(Paul, keep calm! Your uke will reach an accurate intonation, that's for sure!)
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