Coming down the home stretch on the modified Squier Vintage Modified Jazzmaster project.
I'm replacing the El Cheapo© plastic nut with a bone one. So first I removed the plastic one. It's been my luck lately to run into saddles and nuts that are firmly glued in. I had to saw and chisel the old one to get it out.
When it came out, I was relieved to see that the slot bottom is flat! The old Fenders have a curved bottom which is a pain in the bumpkus.
I thickness sanded the nut blank so it would sit perfectly in the slot.
If I cut to the mark, the strings will buzz on the first fret.
I mark the top of the blank and sand some height off on the ROSS (belt sander). Then I make some slots. Then I probably take some more off the top, make the slots deeper, etc.
What I want is the slots to be deep enough that the strings will ride just above the first fret (thousandths of an inch). But at the same time, they should also sit correctly, height-wise, in their respective slots.
Hopefully this will make sense shortly.
Now with those outside slots marked, we can use the priceless Stew-Mac string spacing rule. Line up the two outside slots with marks on the rule, and then use the 4 inside marks in the same row on the rule to mark and cut your slots. I indicated the appropriate marks with green arrows in the picture to serve as a guide. (The outside marks might seem to be off a tad, but that's the angle of the camera and me trying to keep it in line with one hand).
You can measure this all by hand, it's been done that way for centuries. But if you do this a lot, you'll find this rule to be simply golden!
We know the absolute depth - as low as possible without buzzing. But what about the height at the top of the strings?
The general rule is to make the slots so that wound strings sit with about 50% of their height above the top of the nut. Plain strings should sit with their height just at the top of the nut.
You'll see many guitars with nut slots too deep. I'm not sure why this is, other than the fact that this is a bit of a tedious job, and factories just throw them out there. Another reason to know how to do this. If the slots are too deep, the strings will tend to bind and hang up in the slots - bad for string bending or especially vibrato use. The strings won't return to pitch properly if they hang up.
You can also see I've worked the overall height of the nut down as I've progressed. It took me three passes of filing the slots, then taking some material off the top to get to the final stage.
I polished the whole nut with 600 up to 1500 grit paper and then polished it out with fine and super fine compound.
You need to handle the nut with care at this stage. It's relatively thin, and will snap if you mishandle it. I've done that too!
Notice the height of the wound strings - they're about halfway down their slots. Just about perfect. The strings are very low over the first fret - it takes very little effort to play them.
I want to get some other bone - like fossil bone - for some future attempts.
I'm shooting for a hair less than 5/64ths on the bass side and 4/64ths on the treble side, both measured at the 17th fret. What I usually do is put the heights at those measurements, then play the guitar and adjust from there.
I personally like to have the action to where I can easily get my finger(s) under the strings to bend easily and not have the strings slip out from under my fingers. You may like something else, so experiment! I've gotten to the point where a final setup (aside from making a nut or saddle) takes me about 15 minutes. Every guitar player should be able to set up their own instrument.
I'm sure I'll have some small tweaks, but it plays really nice and sounds amazing! The Novak pickups are really something.
The front pickup is very Strat-like, and the bridge is like a combination of Strat and Tele. It's really fat with a nice high end.
I'll get some better pictures of it soon.
All Posts on the Squier Vintage Modified Jazzmaster Modification Project:Part One: Starting Disassembly
Part Two: Removing Factory Wiring
Part Three: Shielding
Part Four: Wiring Modifications and Curtis Novak Pickups
Part Five: Neck Inserts and Installing Mastery Bridge
Part Six: Buffalo Bone Nut and Final Setup (This page)
Part Seven: Modified VM Jazzmaster Visits the Garden
"Ching" Rhythm Circuit Revisited: 28 April 2014