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View Full Version : It shouldn't work, but........it does, but why?



celticskunk@gmail.com
07-24-2016, 10:16 AM
Hi all: My name is Kyle & this is my first post here. I just finished my first real ukulele build after several cigar box ukes. I made a tenor pineapple, but had trouble with the neck & fingerboard I made. I took the neck off and replaced it with a concert scale neck I had. I strung it up, tuned it, and it plays very nicely and intonation is spot on. So here's the mystery, It was set up for a 17" scale, I put the concert neck on, but didn't have to move the bridge to a 15" scale, it just plays nice without moving the bridge. So it's 7 1/2" from the nut to the 12th fret and 8 1/2" from the 12th fret to the saddle. Can anyone explain how that is possible, it's got me stumped. Thanks......

Mimbler
07-24-2016, 12:09 PM
To be perfectly honest, I don't think it is possible. Physics just doesn't kid around! :)

I'm willing to be enlightened by someone who could explain it though.
Mike



Hi all: My name is Kyle & this is my first post here. I just finished my first real ukulele build after several cigar box ukes. I made a tenor pineapple, but had trouble with the neck & fingerboard I made. I took the neck off and replaced it with a concert scale neck I had. I strung it up, tuned it, and it plays very nicely and intonation is spot on. So here's the mystery, It was set up for a 17" scale, I put the concert neck on, but didn't have to move the bridge to a 15" scale, it just plays nice without moving the bridge. So it's 7 1/2" from the nut to the 12th fret and 8 1/2" from the 12th fret to the saddle. Can anyone explain how that is possible, it's got me stumped. Thanks......

pointpergame
07-24-2016, 01:34 PM
There's not quite enough information. If you're like me, you love a nice reductio absurdum problem. Since all the evidence is right before you and the impossible is not possible...it should be easy.

You wouldn't have to move the bridge to get proper intonation, of course. It could just have worked out.

First, and most importantly, does the 12th fret sound the octave? Then the SOUNDING LENGTHS are the same. If two halves are not physically the same length I'd say the first fret is sticking up and cutting off the nut half the string at 7-1/2."

Another possibility: The fretting of the new fingerboard is for 16", not 17"?
Another possibility: Your measurements are incorrect?
Another possibility: The 12th fret is not really the 12th fret?

celticskunk@gmail.com
07-24-2016, 02:35 PM
There's not quite enough information. If you're like me, you love a nice reductio absurdum problem. Since all the evidence is right before you and the impossible is not possible...it should be easy.

You wouldn't have to move the bridge to get proper intonation, of course. It could just have worked out.

First, and most importantly, does the 12th fret sound the octave? Then the SOUNDING LENGTHS are the same. If two halves are not physically the same length I'd say the first fret is sticking up and cutting off the nut half the string at 7-1/2."

Another possibility: The fretting of the new fingerboard is for 16", not 17"?
Another possibility: Your measurements are incorrect?
Another possibility: The 12th fret is not really the 12th fret?

OK, I remeasured carefully and it's 7 1/2 to the 12th fret and 8 1/4 to the saddle. The octave is on the 13th fret. I guess it did just work out because it plays in tune. I was so happy it played nice with the new neck that I didn't think about the idea that it shouldn't work until the next day. Thanks for your input.

BlackBearUkes
07-24-2016, 03:30 PM
Sorry, the octave cannot be on the 13th fret and the instrument play in tune. The center of the octave has to be on the 12th fret, it's the law. In theory, the distance from the nut to 12th fret has to be the same as the distance from the 12th fret to the bridge saddle,plus a little for compensation, but not a full 3/4". It can't play in tune with that set up, period. Test this instrument with one that is correct and perhaps you will hear the difference.

Titchtheclown
07-26-2016, 12:26 AM
As the proud maker of many floating bridge cookie tin ukes I can tell you that being 3/4 inch long at the bridge does not make that much difference on the first couple of frets. In fact I just grabbed a uke and shifted my bridge close to an inch back and the first few frets dont sound too bad at all. However, the difference is cumulative the further you go up the neck. This is why intonation is tested and adjusted by checking at the 12th fret. Just check how different the note is by fingering the 12th fret and finding the harmonic. I cheat because my ear is not that good so I use the tuning app on my phone.

sequoia
07-26-2016, 06:10 PM
However, the difference is cumulative the further you go up the neck.

Yup, it won't sound so bad down along the first couple frets (who cares! It's only a ukulele!), but when you move up the fretboard things are going to become increasingly funky or more "cumulative funk". I've said this before; 90% of uke players never play much beyond the third fret so who cares? Well I sorta do.

celticskunk@gmail.com
07-29-2016, 02:56 AM
Yup, it won't sound so bad down along the first couple frets (who cares! It's only a ukulele!), but when you move up the fretboard things are going to become increasingly funky or more "cumulative funk". I've said this before; 90% of uke players never play much beyond the third fret so who cares? Well I sorta do.



Yes, it does start to get a bit funky as you get past the 7th fret, I guess I should have said it plays in tune with itself as long as I stay away from the upper frets (which I do anyway) I'm just happy I learned a lot (mostly how not to do something) from my first build and already onto number two.