Soprano uke fret tolerances

[sam]

Howdy,

I've just cut fret slots for a soprano uke using the Stewmac mitre jig, their Japanese saw and
a vernier. Checking slots as I progressed from the nut, I'm getting anywhere from .003"
to .018" error in the slot centres (despite following the measure twice...three..four and cut once rule). I'm putting it down to parallax and the moron factor.

In the future I'll probably use a template, but now I would really like to know how to avoid excessive error when cutting for non-standard string lengths AND what are the acceptable
tolerances for this scale of work.

Down but not out,

Sam

[lauburu]

I may incur the wrath of purists and the most discerning of listeners but misplacement of a fret by a fiftieth of an inch (especially up the neck a bit) is not going to matter too much IMHO. The soprano ukulele is not generally regarded as a precision device so being pitch perfect is not an absolute necessity. You could probably create bigger variations in pitch just by squeezing the strings too hard or bending them a bit too far when playing.
A fret template is a good idea but I get accurate results gluing a paper printout from a little program called Fret Calculator onto the fretboard blank and cutting where the lines are.
Miguel

[liam_fnq]

I used to set out and cut my uke fretboards (in a mitre box) by hand. One day I lined two or three hand cut boards up against each other and they didn't line up at all. After that I got a template and not long after that a table saw.

[Allen]

Part of the charm of a uke, especially the soprano is the dissonance you hear in them. They are a folk instrument and were built to be played and enjoyed for what they are. It's really only in the last few years with the advent of cheap electronic tuners and people feeling that because they don't sound like their greatest idol after practising and playing for a full half hour that it must be the instruments fault.

Those variations aren't anything to be too concerned about, especially on your first. I've seen factory instruments that have a fret a full millimetre out of place. Didn't seem to worry the person who bought it or was playing it.

[sam]

Thanks, guys. I'll have a fresh look at it in the morning.

Sam

[ProfChris]

I play soprano uke and have built a few, and can confirm that intonation is rarely better than "thereabouts" because of the short scale and low string tension. If your 12th fret is in the right place and the others are within 0.5mm then it should play pretty well.

I just checked, and increasing finger pressure can give me what sounds nearly a 1/4 tone difference (measured by ear, not electronically) at the 7th fret. Good players tend to adjust their finger pressure to get close to the note they want. Bad players use a death grip anyway, so the placement of the frets is hardly critical!

Some of my first builds had frets that were nearly 1mm out, and they played surprisingly well. But I do like to get as close as possible now.

[sam]

Thanks for your player/builder wisdom, Chris.

I'm more relaxed about the results now, but would like to be able to cut
frets slots more accurately.

I have a jeweller's needle file with a knife edge that cuts a kerf
approximating that of the saw. I might experiment with very shallow cuts, carefully located by vernier, on the inboard corner of the fretboard. These trial cuts would be made out of the mitre box where I can see better - the sawing equivalent of
a pilot hole. When it goes back into the jig I'm hoping a slightly back-tilted saw will lock into an
accurately located pilot kerf.

Sam

[charangohabsburg]

Sam, the fret slot cutting setup Taffy Evans presented recently might be your way to go.

If you still are not satisfied, respectively if your "weak" point is not doing the cut but rather scribing the fret position you probably will want to upgrade to the fret cutting jig "johnosb" presented a few weeks before in the same Jigs & Fixtures section of the ANZLF.

I also think that it is more a visual problem if you are 1/10 mm off on a soprano ukulele, the player's (variing) finger pressure on the strings plays a much greater role, which has to do with the low string tension which is so typical for soprano ukuleles.

Cheers,

[sam]

Marcus,

Those were two very useful links. Thank you.

I'm back on my bike again, thanks to you
chaps.

S