Baritone Uke bridge compensation

[cactus bum]

Hi folks, I am now almost finished with a Baritone Uke with a parlor guitar body and a 20 inch scale length. I have read a lot of forum posts and have yet to come up with the rule of thumb for compensation on a Baritone uke bridge. Yea, some posts on Soprano and other ukes, and even Kasha ukes, but no luck on Baritone Ukes. The otherwise excellent Kawika website omits Baritone compensation. I am not using plans, so I can't go to the designer for help. Allen, are you doing Baritones? I plan to experiment with different strings, so this is why a "rule of thumb" would be useful. I made the bridge straight, ie perpendicular to the neck, and without incline. Any of you want to wade in on this one?

Thanks, Cactus

[Allen]

Not done a Baritone Michael, but I know a fellow who does, so will ask him tonight and get back to you.

[kiwigeo]

Kathy Matshushita posted some time ago with the same question...which never got answered. Looks like she went and worked out the answer her self with a compensation calculation jig:

http://home.comcast.net/~kathymatsushit ... bar24.html

[cactus bum]

Allen & Kiwigeo, Stumac says to use a non-compensated bridge at 20.118 inches. Given Kathy's being unsure about the placement of her bridge on her Kasha Barirone Uke I am unsure also if the Stumac number is right. I only want to do this bridge placement once. Sorry to trouble you, but color me uncertain Also, seems like if the Stumac number is right and then string gauge and action come into play, their number of .118 inches is maybe insignificant, maybe not. Michael

[Localele]

Hi Cactus,
Using Stewmacs compensation will be a good starting point. Depending on the width of your saddle (3mm ?) it should give you enough to get it playing fine.
Remember that it is only a starting point and when taken to the N''th degree compensation is only exact for a given set of strings.Changing string gauges will mean your saddle will be out again.It all changes depending on how hard you fret each string as well . Getting it right at the 12th fret is good enough for my ear and usually where most people check.For variation aim for it to be "slightly " flat rather than sharp at the 12th.
In order to get an idea of intonation changing up the neck put your favourite tuner on an existing instrument and have a play around.Tune it and check the 12th fret.Start a little chart and write down the results for each string all the way up the neck noting where it is sharp and flat.Fret very gently and try to be consistent.You may be surprised at how things move around for the different strings. The chart will give you a visual idea of the problems involved.
Next step is to get stuck into both a cold beer, some long runs of Walkin' Blues a bit of 12bar and finish of with some Ragtime blues. By the end of the first beer and blues session you will realise that you don't need to "fret " over compensation too much for ukuleles.
Hope this helps your building.

[Allen]

I make all my saddles 3mm and use the stewmac calculator, but that is just up to tenors. Micheal (Localele) jumped in here when I pointed him to this thread.

I've found that using the Stewmac Calculator for most of the strings I use puts the intonation pretty much as good as your going to get it on a uke if you round the saddle over about midway through the saddle. Sometimes the C string needs a bit more. I've never kicked the saddle back like you would on a steel string guitar, even though I see some plans call for it.

[cactus bum]

Thanks Michael. Thanks Allen. I will follow your advice. Appreciate you taking the time to respond.

It occurred to me a person could have two or three slightly different drop-in saddles to accommodate different strings or playing styles. Wonder if this is done? I, however, will drink a beer and not fret too much over ukulele compensation.

Cheers, Cactus

[jeffhigh]

Just be sure that you understand that the Stewmac fret calculator gives a figure to the breakpoint on the saddle which is generally in the middle of the saddle slot.
Many others will give a figure to the front of the slot.

[cactus bum]

Thanks Jeff, I was just at the Ukulele Underground site where Kathy M. posted her Kasha compensation question a year or so ago. She was told the middle of the saddle is where to measure to when figuring for compensation using the Stumac numbers. It's good to get this esoteric info out there. Stumac neglects to call attention to this. So it goes. Cactus

[Localele]

In Stewmacs defence here is a copy of the Fret Position calculator printout clearly showing where to measure to. For myself I would have used the metric version to make the measuring easier.This gives a result of :Ukulele - Non-compensated bridge - 510.9972 mm (±0.5mm) 20" fret scale. I would read this as 511mm to the centre of the saddle slot, take off half the saddle width plus the width of the saddle in front of the slot , cut a piece of perspex at this length and 50mm wide to make a great bridge positioning jig.


fret from nut fret to fret
1 1.123" 1.123" (nut-1)
2 2.182" 1.059" (1-2)
3 3.182" 1.000" (2-3)
4 4.126" 0.944" (3-4)
5 5.017" 0.891" (4-5)
6 5.858" 0.841" (5-6)
7 6.652" 0.794" (6-7)
8 7.401" 0.749" (7-8)
9 8.108" 0.707" (8-9)
10 8.775" 0.667" (9-10)
11 9.405" 0.630" (10-11)
12 10.000" 0.595" (11-12)
13 10.561" 0.561" (12-13)
14 11.091" 0.530" (13-14)
15 11.591" 0.500" (14-15)
16 12.063" 0.472" (15-16)
17 12.508" 0.445" (16-17)
18 12.929" 0.421" (17-18)
19 13.326" 0.397" (18-19)
20 13.700" 0.374" (19-20)
Notes on fret layout
The most accurate way to lay out your scale is making all measurements from the nut (using the "fret to fret" distance only to confirm your layout). Laying out frets only by measuring fret to fret will compound error. For example, if you're laying out frets by marking with a scribe and your accuracy is plus or minus 2 millimeters, you could be off by as much as 24 millimeters at the 12th fret.

Measurements are given from the end of the fingerboard (face of the nut) to the center of a fret slot.

Bridge placement for 20" scale

Ukulele
Non-compensated bridge
20.118000000000002 " (±0.030")

Please note that these measurements are based on a mathmatical formula for compensation as well as an average of what "plays in tune" for a variety of instruments. Variables such as string height (action) and string gauge can affect the intonation of an instrument, so you may need to slightly adjust the locations given.

Measurements are from the nut to the "break-point" of the string at the peak of the saddle.



© Copyright 2009 Stewart-MacDonald

[cactus bum]

Would have gotten back to you faster, but it took the longest time to scrape the egg off my face. I am suitably chastized. Thanks for your input.

This stringed instrument building thing is a journey for me. If it were easy or perfectly straight forward it would be much less fulfilling. Sometimes the problems I run into are self made, such as in this case with my lack of careful reading. It makes me appreciate more the patient, generous sharing of information the members of the ANZLF forum give to people like me. Sincerely, Cactus