Official Luthiers Forum!

Hi,

Just joined the forum and have a burning question.

I've been obsessively reading on the net about fretboard work like fretting and fretboard leveling/radiusing. I am building a neck jig and learning how to use it. However, I don't think I quite understand the concept of simulating string tension. I don't doubt that it's beneficial and necessary but it still poses a question in my mind. To me, logic would state that if you are trying to level frets, you would want the neck as straight as possible. No? If you have the neck in a simulated forward bow while leveling, wouldn't that produce a slightly hump with an apex in the 7/8 fret area? I've always been told for a guitar to play correctly, it must have a slight relief in the neck, even .002". But if you level with relief, wouldn't that relief cease to be present once the guitar is strung back to full tension?

Thanks,
-Aaron

_________________
"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

for fender style necks, i just bolt mine onto a beam of maple, then stick that in the vice. i wedge some support underneath the headstock and the middle, to keep the neck from flexing during radiusing/leveling/etc....in other words, dead level, no "relief". works like a charm

In answer to your question, Aaron - NO.

_________________
"Act your age, not your shoe size" - Prince

I asked a few questions. To which one are you referring?

_________________
"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

if you add a hump in the fretboard, which is what adding relief during leveling will do, then it will likely cause problems down the road for future fret/radius work...unless it is YOU doing it, and you can duplicate the amount of relief exactly.
adding a shim in the neck pocket, or building in a slight neck angle in relation to the body, should be effectively the same as adding "relief" during radiusing/fret install.
i have no problem getting super low action on my guitars that were constructed with level fretboards.

Always been my way to make the frets dead level and set relief with the truss rod. But I can see a jig like Erlewine's helping to work out fret board humps at the body joint that tend to only show up under string tension.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I built one of these some time ago, and there are definitely steps to follow.
The idea is you adjust the trussrod to get the neck straight under string tension. Then remove the strings & get the neck back under (the same) tension using the jig. Now level the frets.
Put the strings back on (which should now result frets dead level and "zero" relief), and dial your relief by adjusting (ie backing off a bit) the trussrod. Hope this clarifies.

_________________
Dave
Milton, ON

I understand there are differing opinions on this topic. Diversity is the spice of life. I get it. I'm just trying to understand if the people using the neck jig are making the necks straight through counter tension between the jig and the truss rod the same way it happens when the guitar is strung up to tension or if the jig is putting relief in the neck. The first one makes more sense to me than the second.

_________________
"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

My bad. Your final question.

_________________
"Act your age, not your shoe size" - Prince

When you set the jig, you tune the guitar to pitch and use the truss rod to get the neck as dead straight as you can, BUT the neck never comes dead straight. It's always got little bobbles in it here and there. Then you remove the strings and simulate the string tension. When you're done you've now hopefully reproduced the little bobbles that show up under tension.

So with a perfect neck, the neck jig is irrelevant because it will come dead straight both both with and without string tension. With a real neck, it always does something a little different with tension than without. Some are worse than others. I did a neck a few months ago that would have been practically impossible to fix without the jig. It had a funny kink under string tension. Using the jig the neck was trivial to fix.

I like to stand up and move my head around every 15 minutes to relieve my neck while doing fretwork.

The neck jig makes sense to me, but not to my pocket book or patience.

_________________
wah
Wah-wah-wah-wah
Wah

I think you would be interested to hear this, as it is the opposite of what the neck jig does for you.

I worked at Warmoth for about a year and before we would radius fretboards we would actually adjust the truss rod for mild to moderate backbow. The reason for this is to purposefully remove slightly more material from the middle of the fretboard. We would refer to it as "radiusing relief into the neck." All Warmoth necks have only a one way truss rod so it was important to be sure that the neck would have enough relief because forcing it forward is not an option. If you have a Warmoth neck and you measure the thickness of the fretboard at the ends and the middle, you will see that the fretboard is slightly thinner in the middle section.

Whatever technique you choose and whether you use a neck jig or not, the important thing is merely being able to have proper relief without resorting to maxing out a truss rod. If you can make a neck and string up the guitar and not even have to put forward or backward pressure on a trussrod then you are doing something very right.

Thank you. I've often thought about this and wondered if anyone ever did it. Warmoth makes amazing necks so this is good to hear.

_________________
"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."