# Straight Edge



## dcole (Oct 8, 2008)

Hello,

What do you experienced fellows use for a straight edge when looking for straightness of necks and adjusting action? Will this double for checking out fret levelness?

I was thinking of this http://www.leevalley.com/us/wood/page.aspx?c=&p=50074 as it can be easily had up here in Canada. I am afraid the straight edge is too wide and would make it difficult to accurately gauge straightness and action due to the radius on fretboards.

Thanks,

David Cole


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## dradlin (Feb 27, 2010)

You don't need a tool... use the strings as a straight reference . Depress the string at the first fret and a fret at the body joint, then tap the string at the mid point between the depressed points. Tighten the truss rod until the string stops bouncing when tapped, then loosen the truss rod until it just starts to bounce.


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## dcole (Oct 8, 2008)

Can you use this technique with the string to determine high and low frets?


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## Guest (May 24, 2015)

sight down the fretboard. if any frets are out, you'll see them.










as to truss rod adjustment. I also use the string as a straight edge. fret the low
E string at the first and last fret. eyeball in the middle. should be a small gap.


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## nnieman (Jun 19, 2013)

An old credit card makes a great `fret rocker`.
http://www.stewmac.com/Luthier_Tools/Types_of_Tools/Straightedges/Fret_Rocker.html


I made a straight edge out of wood but those lee valley ones should be good for woodworking.


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## dcole (Oct 8, 2008)

I certainly like the idea of not using tools when not required.

I was looking at my Fender neck in a bright light and found if I focused and the 1st fret with wood in between frets and started leaning the neck so that the wood disappeared, each fret came together smoothly across the entire length of the board. Would this be a good description of what to do *laristotle*?

Do you end up cutting one end of the credit card down *nnieman*?


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## Steadfastly (Nov 14, 2008)

A large carpenter's square can be used as well.


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## dradlin (Feb 27, 2010)

Steadfastly said:


> A large carpenter's square can be used as well.


A carpenters square is a crude straight edge, with a straightness tolerance that is larger than the straightness to be achieved. 

Ideally, a notched straightedge (stew mac) gives you the best read on neck relief, both visually and measurably and un influenced by irregular fret tops. 

But even a notched straightedge can "lie" if the fret tops are leveled out of plane with the fingerboard, so I set with a notched straightedge and verify using the string method.


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## dradlin (Feb 27, 2010)

dcole said:


> Can you use this technique with the string to determine high and low frets?


The problem with a fret rocker is that you can be fooled to think that a fret is high when the actual problem is an adjacent fret being low. Spot leveling with a rocker as a reference tool can exacerbate the problem, especially with inexperience.


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## dcole (Oct 8, 2008)

Would you go on a fret either side and if the fret rocker drops both times onto that fret, it would be low then?

Almost need a straight edge to determine just how true rulers and carpenters straight edges are.


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## dradlin (Feb 27, 2010)

dcole said:


> Would you go on a fret either side and if the fret rocker drops both times onto that fret, it would be low then?
> 
> Almost need a straight edge to determine just how true rulers and carpenters straight edges are.


I mostly use a rocker only to determine that there are irregularities, and then level high spots with a leveling beam as long as the fingerboard.


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## dcole (Oct 8, 2008)

That makes sense.


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## Steadfastly (Nov 14, 2008)

dradlin said:


> _*A carpenters square is a crude straight edge,*_ with a straightness tolerance that is larger than the straightness to be achieved.
> 
> Ideally, a notched straightedge (stew mac) gives you the best read on neck relief, both visually and measurably and un influenced by irregular fret tops.
> 
> But even a notched straightedge can "lie" if the fret tops are leveled out of plane with the fingerboard, so I set with a notched straightedge and verify using the string method.


You can't be serious. Why do you think it is crude?


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## dradlin (Feb 27, 2010)

Steadfastly said:


> You can't be serious. Why do you think it is crude?


Because when I put my precision straight edges against my typical framing squares it proves to be crude!


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## Electraglide (Jan 24, 2010)

The large carpenters square I use at work is not crude. Neither is the large drafting/machining square I use. That being said, I prefer using the string method. It's always there and it's always the right length. Also, it's very easy to use. You don't have to worry about the other arm. How do I check my squares? I use a high e string stretched tight between 2 pins set 26" apart.


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## fraser (Feb 24, 2007)

i always do like laristotle pictured.
then if needed ill use a straight edge.
my straight edge is just a 3 foot metal yard stick type thing.
it was cheap.
i dont feel it necessary, but why not.
i have another one that i cut up into various lengths for use as a fret rocker-
i never really use them except when actually refretting.

i dont personally think exact bang on precision is necessary for a guitar neck as far as levelling/setup goes.
if a problem fret exists you will know it by simply playing the guitar.
expensive precision tools are worth it if you are spending all day setting up guitars that you dont have time to play-
but a few minutes of noodling can tell you all you need to know,
if you learn what to look for.

i prefer to use the most basic and primitive tools i can.
if they arent cutting it i use something else.
just go to the hardware store, find a couple metal straight edges.
i know mine are straight because i tested them on one of those machinists marble surfaces.
and they only cost a few bucks each.


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## knight_yyz (Mar 14, 2015)

http://www.stewmac.com/Luthier_Tools/Types_of_Tools/Straightedges/Notched_Straightedge.html


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## Steadfastly (Nov 14, 2008)

dradlin said:


> Because when I put my precision straight edges against my typical framing squares it proves to be crude!


In what way? Please explain.


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## dradlin (Feb 27, 2010)

Steadfastly said:


> In what way? Please explain.


How about .03" out of straight... I have two of them here and both are off, and that is what you can expect from a carpentry tools. I have a metal meter stick too, it's off the same.

.03" is suitable for carpentry, but not suitable for precision neck, fingerboard, and fretwork.


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## knight_yyz (Mar 14, 2015)

There are a few things you could try to buy that are better than a carpenters square and wont break the bank. You could get a 24" machinist rigid scale (ruler) made of metal and will be very accurate, probably +/- .005. You could get a combination square, but name brands can be costly, they are just a fancy ruler made of metal but precision ground and comes with the sliding L shape to make it a good square. . 
My machinist square at work is accurate to .0001" if used correctly, but you don't need anything quite that accurate. Dradlin is correct, if you put my machinist square up against a cheap carpenter square, the carpenter square is out by a mile. 

You can get a decent 24" chinese machinist scale which is basically a metal ruler for about 50 bucks and it will be precision ground and good for .005" Spend more money and get even more accurate. Cheaper than a true straight edge. 

A 24" straight edge can be anywhere from 75-500+ depending on accuracy, but again a cheap chinese knockoff is probably good for .005'. I can get a straight edge 36" long which is accurate to .0005 per foot for about 140 CDN plus taxes. (8 pounds though)
A top brand 24" scale is about the same price because you are paying for the graduations on them. But they are a lot lighter.
A 24" machinist square with a 13 inch base is about 150 for a decent one.


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## Steadfastly (Nov 14, 2008)

dradlin said:


> How about .03" out of straight... I have two of them here and both are off, and that is what you can expect from a carpentry tools. I have a metal meter stick too, it's off the same.
> 
> .03" is suitable for carpentry, but not suitable for precision neck, fingerboard, and fretwork.


Well, I never knew that. Thanks for sharing the information.


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## YJMUJRSRV (Jul 17, 2007)

gone fishing


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