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String Tension Jig


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Here at Martin we used weights to simulate string tension, by supporting the lower part of the body and under the nut.

I've been doing something like this, only cause i think dan erlewine's stew-mac jig is total overkill and way to pricey.

I finish my necks and bodies separate, so after i have the neck / fb together (before fretting), I place a temporary pre slotted nut on the neck and attach the neck to a "dummy" body with 4 screws. The body has a wraparound bridge on it already. I then tune it to pitch and adjust the rod to make it as straight as possible under string tension.

I place it in the jig (pictured below) and adjust the red standoffs so they are just touching the bottom of the neck in three places.

I then remove the strings and the neck goes obviously goes back where it was before tension. Now i place the unstrung guitar on the jig and add weights to the upper bout of the dummy body to curve the neck back down to the red stops (that are locked into place from before)

Then flattened the fret board using the different grits of sandpaper on my long straight radius block.

Remove the neck from the fixture and dummy body, install frets.

Attach it once again to the dummy body, place back in jig, add weights like before. Now i fill do the fret leveling.

Anyone see how this is so different from Dan Erlewine's method? Comments? suggestions??



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Since I do not do repairs anymore I have no need for a neck jig. On the new guitars I string them up for a few days at pitch to set the fret tangs, adjust trussrod, do a setup, take the strings off, then level and dress them as normal.

I have not seen where a neck jig would improve this process as usually my customers have to raise the action on my guitars when they get them.

For older repair work I could see it as useful where the neck might be less stable.

In the old days (late 80s) I used a Stew Mac jig on all the vintage instruments I worked on because it made the customers feel warm and fuzzy seeing such an elaborate setup.

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I have built a neck jig and occasionally use it for tricky fret jobs on necks that are straight when the strings are off, and twist under string pressure. However I more and more tend to use Rick Turners method, level the frets with the strings still attached.

For my builds, I don't have any problems. Probably because I over-engineer the necks...

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Ultimately it comes down to what brings people to your shop and makes them put profitable work through your door. Often, having some whizz-bang gizmo with all the straps and dials you can is impressive to the lay person who probably doesn't understand these things. It makes them, the solution to their problem, your shop and you seem very very impressive.

I have never had a problem creating a slick setup on an instrument using anything more than the most basic of tools. This does not differentiate me well enough from the next reasonably-educated luthier or guitar tech down the road to bring more work my way. Simple things like this might not make your setup any better but they can certainly make a difference to the amount of work you see coming your way. In that respect they probably pay for themselves, which is just weird.

Actually, I just re-reviewed the thread and clicked on the link to frets.net in the Google search results. Seems that I am not alone in thinking this about these jigs.

Aside from the impression they make on customers, these crazy space-age jigs are only worth the problem that they solve and not the one that they create in the customer's (or worse, the luthier's) mind. The square metre or so of space taken up (plus room around it to manoeuvre) plus the money they cost to buy would be better spent on a sofa chair to share the odd half hour chatting over coffee or a dram of whisky with customers. That's how you integrate your skill set into the local musician's community.

Rant over.

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So my follow up question for you guys is... For new builds, not repair work.... Do u sand the Fretboard flat before installing frets? Sand with a drop? Sand under tension? Or just level the frets and leave the fretboard alone. Maybe I am doing too much prep work to the fretboard.

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I level the fretboard after it s glued onto the neck and after the bulk of neck wood has been removed. I have noticed that if I sand the fretboard level when I have the neck blank thick and nice there will some times be some movement when I remove wood from the neck and if I sand only after the neck have reach its final shape (not finish sanded, but nearly) I have considerably less movement and I just need to slightly kiss the tops of the frets after they have been seated properly.

It also add the bonus that, when I clamp the neck upside down to shape the neck, the fretboard is flat and it is much easier to clamp it solid.

I'm not saying that my way is the only or the best way to do things, just sharing what I do...

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