Don't Have A Fancy Stewmac Neck Jig... Questions

[RickBlacker]

Hi all.

I have an old peavey tracer 22 fret neck i purchased off ebay about a year ago. Looks like rosewood fingerboard over a maple neck. It needs a new fret job and looks like a fretboard sanding. A long time ago I purchased Stewmacs fretting tool kit and fretwire. All this has been sitting for a year until I found time to build my Gibson Explorer cloneish guitar. I say clonish because I realize that the scale I'm going for is not the same as the original Gibson Explorer, thus have to ensure I'm to my 25.5 scale.

I have the Stewmac "Fret Work" book. One of the chapters is about working on fender style necks. They do a complete refret and repare. HOWEVER, they do it all on their Stewmac neck jig. I don't have one, have no desire to shell out $300+ to buy one. At this time, not really interested in building one either.

ANYWAY (sorry long intro to my question)

With the neck off the guitar, no tension, is the neck supposed to be perfectly straight with no releif and or back bow?

[avengers63]

yep

But don't be surprised if it isn't. There's always a chance that having tension on it from the strings and the truss rod for so long could have bent it permanently.

[RickBlacker]

yep

But don't be surprised if it isn't. There's always a chance that having tension on it from the strings and the truss rod for so long could have bent it permanently.

Great, I'm going to pull the existing worn down frets this morning and start checking things out.

[WezV]

its not a problem if it isnt perfectly straight - you want a bit of relief. some necks will be straight and get the relief needed from string tension, some wont move much under tension and it will need dialing in with the truss rod

what i usually do is add a very small amount (very small!!) of back bow with the truss rod before levelling the frets (especially if its a one way rod). this means its perfectly level with no string tension and a little tension on the truss rod. then string tension usually pulls it into relief, but when it doesnt i can loosen the truss rod a bit to dial it in , or if string tension pulls it into too much releif i can still tigthen the rod more.

By adding the little tension first it creates a limited amount of forward movement you dont usually get with a one-way truss rod. If you already have a 2-way rod in the neck you can do everything perfectly level and have much more control after

never used a neck jig, i can see the appeal but its not hard without them

so you are refretting this neck - so when the frets are out check if the board is level - if not make it perefctly level with truss rod adjustments and re-sanding the radius if needed before fretting, this is important and from then on control as above

[devnull]

I guess I don't understand this stewmac fret jig.

When you are sanding the fretboard, and leveling the frets, you want the neck to be perfectly straight, don't you?

The stewmac fret jig simulates string tension.

That's nice. But, when you are sanding the fretboard, and leveling the frets, you want the neck to be perfectly straight, don't you?

[Buter]

You're not wrong.

When you are making a neck from scratch, you will have a perfectly flat board and levelled frets (in theory).

When under string tension, the neck will obviously develop a bow which can then be eliminated, with the desired relief left in place, with adjustment of the truss rod.

Since you started with a flat board and returned to a flat board, you have no need for a neck jig when building a new neck.

I think that the neck jig is an excellent tool for a repair shop, where you do not get to dictate what condition the neck is in when you begin to work on it. IMO, repair work is a different skill set to building guitars from scratch. Repair work is certainly no less important than building but a greater knowledge of how many different manufacturers construct their instruments is required before you can even begin to be a good repair tech. To build good guitars, you only need to know how you build them.

Cheers

Buter

[SwedishLuthier]

I guess I don't understand this stewmac fret jig.

When you are sanding the fretboard, and leveling the frets, you want the neck to be perfectly straight, don't you?

The stewmac fret jig simulates string tension.

That's nice. But, when you are sanding the fretboard, and leveling the frets, you want the neck to be perfectly straight, don't you?

The thing with the neck jig is that a neck doesn't bow 100% uniformly. That means that the wood in different part of the neck ´have different qualities depending on how it has grown and thus a short section can bend a bit more and another section can bend less. So when using the fret neck you put the neck under stress to have the same effect as if the strings pulled on the neck, but with the neck adjusted to be straight. Now if the neck has some irregularities in it it would appear a bit "wavy" if looking down the neck (we are talking very small deviations here) and when adjusting the frets you take care of that "waviness" that also will appear when the neck is allowed a small relief. In that way the curve of the fret tops will be closer to an ideal curve.

Not really easy to explain in words, but I hope you get it...

[devnull]

I guess I don't understand this stewmac fret jig.

When you are sanding the fretboard, and leveling the frets, you want the neck to be perfectly straight, don't you?

The stewmac fret jig simulates string tension.

That's nice. But, when you are sanding the fretboard, and leveling the frets, you want the neck to be perfectly straight, don't you?

The thing with the neck jig is that a neck doesn't bow 100% uniformly. That means that the wood in different part of the neck ´have different qualities depending on how it has grown and thus a short section can bend a bit more and another section can bend less. So when using the fret neck you put the neck under stress to have the same effect as if the strings pulled on the neck, but with the neck adjusted to be straight. Now if the neck has some irregularities in it it would appear a bit "wavy" if looking down the neck (we are talking very small deviations here) and when adjusting the frets you take care of that "waviness" that also will appear when the neck is allowed a small relief. In that way the curve of the fret tops will be closer to an ideal curve.

Not really easy to explain in words, but I hope you get it...

Hey thanks for your response. To clarify:

Ok, so you put the neck in the fret jig and dial in the string tension. That curves the neck. Then, you use the truss rod to straighten the neck back out. At that point, it should be perfectly level, but if there are irregularities in the neck's strength it won't be perfectly level. So you level/dress/crown/etc the frets at that point. Then you release the truss rod, take it out of the jig, put the strings back on (skipping a few steps here..), adjust the truss rod for relief, and you should have no waves due to the varying strengths of different sections of the neck. Is that what it does? Allow you to compensate for the different sections of neck having different strengths?

[SwedishLuthier]

Hey thanks for your response. To clarify:

Ok, so you put the neck in the fret jig and dial in the string tension. That curves the neck. Then, you use the truss rod to straighten the neck back out. At that point, it should be perfectly level, but if there are irregularities in the neck's strength it won't be perfectly level. So you level/dress/crown/etc the frets at that point. Then you release the truss rod, take it out of the jig, put the strings back on (skipping a few steps here..), adjust the truss rod for relief, and you should have no waves due to the varying strengths of different sections of the neck. Is that what it does? Allow you to compensate for the different sections of neck having different strengths?

Spot on! Have saved a few necks that have come in that have looked more like propeller blades than guitar necks.

And you can easily make you own neck jig with all info that is out there. Use a solid wooden beam, two relatively inexpensive dial indicators (the cheepo Chinese once is more than sufficient), some adjustable rods (I use threaded rods with a cork padded surface against the neck), something to adjust the height of the guitar and you are more or less there. If you like I can post some pics of my home made version.

[devnull]

Hey thanks for your response. To clarify:

Ok, so you put the neck in the fret jig and dial in the string tension. That curves the neck. Then, you use the truss rod to straighten the neck back out. At that point, it should be perfectly level, but if there are irregularities in the neck's strength it won't be perfectly level. So you level/dress/crown/etc the frets at that point. Then you release the truss rod, take it out of the jig, put the strings back on (skipping a few steps here..), adjust the truss rod for relief, and you should have no waves due to the varying strengths of different sections of the neck. Is that what it does? Allow you to compensate for the different sections of neck having different strengths?

Spot on! Have saved a few necks that have come in that have looked more like propeller blades than guitar necks.

And you can easily make you own neck jig with all info that is out there. Use a solid wooden beam, two relatively inexpensive dial indicators (the cheepo Chinese once is more than sufficient), some adjustable rods (I use threaded rods with a cork padded surface against the neck), something to adjust the height of the guitar and you are more or less there. If you like I can post some pics of my home made version.

Thanks, pics would be excellent if not too much trouble.

[DC Ross]

There's a PDF floating around by Matt Vinson that oulines how to build one in detail.

[Woodenspoke]

To answer the OP when you remove a neck and the strings most likely the trussrod has been adjusted to compensate for the tension of the strings. So my answer is NO the neck should not be sanded until the trussrod tension has been released.and the neck checked for straigntness. Readjust the TR if it is way off and before you sand. When you are finished you will again need to adjust the TR once the strings are back on. Maybe someone said this maybe not.

As far as the SM neck jig all it does is position the neck to simulate string tension without the strings, which also accounts for a TR under proper tension. I am trying to clarify some comments that were all correct. This allows a finer adjustment of the neck as you cant sand a FB with the strings on and under tension. Without the instructional viseo its hard to picture what it does and why you would want or need one.

People fixed FB and refretted guitars long before this device, but it is a tool that make the job easier.

[brian d]

An alternative to levelling the frets using a jig which replicates the string tension, is to level under actual string tension. Put a temporary high nut on the guitar (I used a hardwood scrap) and use a L-cross section aluminium bar with abrasive on one side. The abrasive fits under the string and levels the fret under each string individually. Then remove the strings and finish crowning as usual.

[SwedishLuthier]

Forgot that I should post pics. The jig:

Two 2x4 glued and screwed together for rigidity. For an extra super rigid beam you could even add another 2x4 on top of everything making it into a wooden I-beam. Super rigid. And then add a platform for the guitar to rest on or for the "resting posts" to anchor to. I covered it with cork to avoid future accidents.

Another shot:

http://i19.photobucket.com/albums/b162/SwedishLuthier123/KopiaavDSCF3386.jpg

Adjustable posts for the guitar makes it possible to use on guitars with a heavily ached backs (OK, maybe not an Ovation ...)

http://i19.photobucket.com/albums/b162/SwedishLuthier123/KopiaavDSCF3389.jpg

Before the neck jig is used the neck is adjusted to as close to perfectly straight as possible with the strings on and tuned to pitch

The posts are simple screw with knobs covered with cork. just simply turn to adjust. The screws closest to the neck even have knobs on the bottom too so that I can reach beneath the jig to adjust.

http://i19.photobucket.com/albums/b162/SwedishLuthier123/KopiaavDSCF3390.jpg

With the guitar secured in place with a cargo ratchet (I think thats the name) the dials are zeroed in:

http://i19.photobucket.com/albums/b162/SwedishLuthier123/KopiaavDSCF3393.jpg

After the removal of the strings the adjustment screws are used to dial the neck back into the zero position

http://i19.photobucket.com/albums/b162/SwedishLuthier123/KopiaavDSCF3396.jpg

An alternative to levelling the frets using a jig which replicates the string tension, is to level under actual string tension. Put a temporary high nut on the guitar (I used a hardwood scrap) and use a L-cross section aluminium bar with abrasive on one side. The abrasive fits under the string and levels the fret under each string individually. Then remove the strings and finish crowning as usual.

Thats what I do most of the times. The neck jig has the advantage not having the strings in the way. Makes dealing with really difficult necks a bit easier. Full access.

Questions? please let me know and I'll try to clarify

[devnull]

Sweet!!! Now, just to be absolutely super duper sure in my understanding, you get the neck under simulated string tension, then use the truss rod to straighten out the neck, and THEN you level. Right?? If so, then *now* I get the stew mac neck jig thing!

Thanks!!!

Edited January 26, 2011 by devnull

[SwedishLuthier]

Well almost... You straighten the neck using the truss rod with the string still on the guitar. Remove the strings and you get a back bow. The jig let you dial in the effekt of the string tension again including all small imperfections via simulated string tension. Then you level the frets to a perfectly straight level.