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Hey everyone,

After an exhaustive search for a 24.5" pre-slotted fingerboard (found at LMII), I'm wondering whether or not I should just bump it up to a standard scale of 24.625 or 24.75.

In the experience of people who've built short scale instruments, what are the advantages or disadvantages for using a "shorter" scale? (I've only built and play on 25.4" or longer.)
How much of a difference is going to be noticed by using a scale that is 1/2", 1/4, or even 1/8" shorter or longer than "normal"?

Hopefully someone can shed some light on this.

Thanks

Dave

Advantage of short scale is less string tension at a given pitch for a given string gauge.

It will be near impossible to find pre manufactured short scale components for anything other than Martin 24.9 scale.

If you want to go really short scale, you can buy preslotted baritone uke fretboards. Scale length is 20 1/4. Might work a half size guitar.
Bob

Thanks guys,

But... I'm really wondering about how it sound. If it calls for 24.5" scale length and I scale it for 24.625 or 24.9", will the increased tension of the longer scales significantly increase the force that drives the top, or will the difference be insignificant? (the longer scale will also place the bridge closer to the sweet spot in the center of the largest vibrating plate on the top, which will surely help with the bass and overall fullness of tone, but will necessitate a longer bridge in order for some coverage of the X braces.)


Come to think about it, I'm REALLY grateful to Michael and Bob for their replies.

They forced me to re-work it out in my head and I think I just answered my own question.

The longer scale actually makes sense in order to meet the tonal considerations I'm building for.


It does beg the question "why did Martin use such a short scale on the original?"

Dave

Depends on what you do with the tops brackng. you can move the that so called sweet spot in may differnt ways. so ther is no one answer.

The box is already closed up so, that limits the variables a bit.

d

Dont forget you can always use a longer scale FB, then chop off the first fret ... I am pretty sure this is why larrivee parlours are 24 inch scale .. its a 25.5 FB with the first fret chopped off.. no need to re-tool !!!!

_________________
Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Thanks Tony,
I thought of that and looked at every standard scale length up to 34" (bass) and nothing quite came close enough to my parameters of keeping the bridge under 6.5" long, covering the bridge plate that is already in there, and the scale over 24.5".

Yeah... What Tony said.
I am building a parlour guitar (more or less) to the Antes' drawing & my 660 mm template worked almost perfectly chopping it off at the first fret... Within 2 mm of the scale on the plans.

If the box is closed up and your bridge plate is the small parlor size aren't you pretty well committed to something pretty close to 25.5 if you followed the plans? Probably better put a light in the box, turn off the room lights and mark the front and back of the bridge plate so you have some idea where you are with a different scale length. I built mine with 24.9 and didn't have to move the bridge plate much from the plans so that should work.
Terry

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

Welllll, back in the 'old days' we used to slot our own fingerboards. Yessiree Bob. Why, I kin remember havin' t'grind some set off a hacksaw blade to get the right kerf for the frets. Boy howdy, but them was the days.

Slotting a fretboard by hand is not simple, but it's not rocket science, either. It's just a matter of measuring accurately, at least twice, before you make the cuts, and then cutting on the lines.

One nice thing about slotting your own; you're not limited by what you can buy from one of the supply houses. I just cut a couple of 'boards in persimmon wood for some 'eco-friendly' guitars with no tropical wood, to take to Montreal. Last year Ihad to leave my best guitar at home because it was made of BRW, but this year I'll have something to show that nobody can complain about. What if you wanted to make a 'fanned fret' guitar? As far as I'm concerned, it's just one of the things a luthier ought to know how to do.

Allan,
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I'd considered that. Really I had. I even started shopping for a saw that would do the job.

Seriously though,
I've built each and every part of this instrument by hand, including the binding, purfling, inlay. The braces and top were cut from the one and only quartersawn 40yo tight grained Douglas Fir fence board I could find on my wife's family farm in central South Dakota. My father-in-law remembers the day the wood came to town by train in 1960!
They recently tore down the fence, and I had to sift through a pile of hundreds of boards in order find this one.

The nuts and saddles are coming from a huge sun bleached cow bone and I'll do the stinky work of cutting them myself.

However...
I don't trust myself to slot a fingerboard accurately enough to ensure the perfect intonation I'm accustomed to getting.

Thanks for the laugh Allan. I needed that.

Dave

I must be missing something. If you've done all this to build the guitar, then slotting a fret board is going to be a piece of cake. Seriously.

Living in Australia, and the exorbitant cost of shipping, I've had to learn how to slot a fret board from my second build. I just made my own mitre box and purchased a fret saw. Don't own a table saw so had to learn how to do it by hand. Use Stew Mac's fret calculator to get fret positions and off you go.

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Allen R. McFarlen
Barron River Guitars & Ukuleles
Facebook
Cairns, Australia

That's what I think, Allen. The fret board slotting has to be one of the simpler processes of building, if you ask me, unless you are trying to slot inside a binding, or something like that. If I had known it was this hard, I would still be working on number one. I put the lines on the board, and cut on the lines. For some reason, I can't imagine why, it worked.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

I'm building my second right now and made this out of an old plane. Plane one edge of the fingerboard straight. Use a good scale and some magnifying glasses. Scribe all the locations without moving the scale. Check at least twice as Alan said. I took enough time on my miter box to make sure it was dead accurate. Sanded the sole of the plane flat and added purpleheart depth stops. I went back and checked the slots when I was done and the worst one was off less than .010" barely perceivable when looking through a magnifying glass. You can make that up when crowning the frets if need be. I say give it a shot. This is how I'll be doing mine for a while, as I can spend my money on other things.



Cheers

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Horton, MI

It's easy to set up a spreadsheet to calculate fret distances. Each fret is 1/17.817155 of the remaining distance to the theoretical saddle position, with no compensation. I actually wrote a small program in BASIC that I still use. It prints out both the distance from the fret to the saddle, and the fret to the nut. I find this really helpful.

When I'm laying out the 'board, I use three clamps to hold the steel ruler down; that way, when I move one there's no chance for it to slip. I start with the nut location at zero, and use the 'nut to fret' numbers and a knife point to mark each fret location to within .2mm (.008", which is about as close as you can see them). These days I use a magnifier. When I have all the fret locations marked, I remove the ruler and use a square and the knife to strike the lines.

NOW COMES THE IMPORTANT PART! Clamp the rule back onto the board, but reverse it. If I'm using a 650mm classical scale length, the zero of the rule will be where the bridge will go, the 12th fret at 325mm, and the nut at 650. Check the scribed lines against the 'saddle to fret' table. Any that are off by more than .2mm I mark with a little arrow, to show which side of the line to cut on. If they're off by more than .5mm I re-mark, and re-check them. I slot 'on' the line; with the marked line being in the center of the slot. Since the kerf is .5mm, cutting to one side of the line moves the slot .25mm to that side. Remember to cut the nut slot to the side of the line.

What I've found is that if I use the same table to both mark and check the fret locations there's a tendancy to read the numbers wrong the same way both times. Reversing the rule gives you an entirely different set of numbers, and you're less likely to see what you remember, rather than what you're looking at. You'd be amazed at how easy it is to get something a full 5mm off, just because you fixed on the wrong line on the ruler. Looks pretty stupid, too, AND it's hard to fill in.

I've used the old 'Blitz' backsaws for years. They don't make them any more, but you should be able to find something that cuts the same kerf. Those little saws can't really be set to provide clearance for the dust, and tend to bind in ebony after a few cuts. The burr left from sharpening acts to increase the kerf enough to provide clearnace, and once it's gone things get difficult in a hurry. I have found I can sharpen the saw pretty quickly and restore it to smooth cutting.

You'll need one of those little 3-square (tiangle) diamond needle files. I get them from Micro-Mark or the local hobby shop. Clamp the saw in a vice, so that there is very little of the tooth side of the blade clear and it's nice and stiff. Roll the side of a black felt tip pen along the teeth, to blacken in the gullets. Now use the diamond file to take one or two light strokes across every other tooth. I hold the file level, and perpendicular to the blade, as if I was sharpening a rip saw. Match the file angle to the rake of the teeth. It's easy to see which ones you've hit: the gullets are shiny. When you have hit every other tooth turn the saw around in the vice and get the other ones. Filing every other tooth in the opposite direction makes the same burr on each side, and keeps the saw cutting straight and smooth.

I've never used a miter box, but I can see where it would be handy so long as you can dress one edge of the board off parallel to the center line. Sometimes I used to get one that was too narrow for that, and had to use a protractor to scribe the lines instead.

Slotting a freboard is not hard, but it is fussy. So are a lot of the other things you ned to do to make a guitar. Knowing how to lay out and cut a board frees you up in some ways, and it's a good thing to learn.