StewMac Safe Slot for building perfect guitar nuts
V-1796
Cutting string slots is delicate: if you cut one slot a little too low, you've blown the nut and have to start over. Elliot John-Conry shows us how using the Safe Slot can help you build a perfectly shaped nut for your guitar.
Video Transcription
[on-screen text reads: StewMac tools + ideas for guitarmaking. Safe Slot For Guitar Nuts]
Elliot John-Conry: One of the hardest things to learn how to do is to make a nut. Seems like a simple thing but there's quite a bit to it. You have string depths to consider, spacing, one or two file strokes and you've got a slot that's too low and then you've got buzzing. Then you have to go back and do it all over again.
We developed the Safe Slot to help you set the top contour of the nut from the base to the trouble side and to set the depth of the slots. Before we get started with the Safe Slot, we want to dial in our setup.
Dialing in our initial setup
I've got the bridge radius set. I've got my 12th thread action, right where I want it and I've adjusted this neck. It's going to be dead straight, no relief and these frets are perfect. If you want to make a new nut, you've got to make sure the frets are right first.
So we're ready to go. I've got my nut fit to the slot. It's a nice snug fit. I'm going to mark my ends, mark the outside ease and then I'll go ahead and mark the remaining four strings, just roughly. Now I'm going to measure the distance between the fingerboard and the top of the frets underneath the lie of each string.
You hear that click like that is too high. So get a different stack of Feeler Gauges.
Using the Safe Slot
That's close. Pretty even fret across the board. We're going to use the Safe Slot Neck Caul and three Feeler Gauges that we use to measure our fret height. You just want to snug it. If you over tighten it'll hump the feeler gauge up in the middle and throw off your pencil line. We're marking the fret height across the nut for our own reference here. Then you add the string height you want over the first fret that tells you how deep the bottoms of the string slots need to be. Then you add half the diameter of your strings. That's the height of the top of the nut.
So we're going to write that number down and save it for later. The shape of the nut should taper from higher on the base side to lower on the trouble side. This flexible shim fits into the Safe Slot, like a feeler gauge [on-screen text reads: Electric Wedge - stewmac.com]. It's tapered with a three quarter degree angle, which is what you want for an electric guitar. Two of these come with the Safe Slot, the other ones, a 1.3 degree angle for acoustics or electric players who like a heavier string or higher action. Use the tapered shim to set the correct shape sloping from high on the base to low on the treble and strike your line.
Shaping the top of the nut
Staying on the top side of the pencil line for now, I'm going to shape the top of the nut. So you need to reestablish your outside E string marks. Then I'm going to bring the Safe Slot in with my three quarter shim and this nut rule is made to fit the Safe Slot. Now I can get a really accurate layout.
Cutting the slots
I've got my feeler gauges set. We'll load them into the Safe Slot and cut the slots to their file side to side a little bit, just to open up the top and as soon as you hear that little drag, you've reached your depths.
I'm going to change out my feeler gauges for the D and the G. We needed 66 thousandths for the E and the A. Now to remove that pencil line, that's at the top of the nut and we're not finished shaping it yet. We're just removing that pencil line. So we have something close to final slot depth. I have the guitar strung back up to pitch. I need to check my first fret action and my 12th fret action. You want to go down and check each individual string [on-screen text reads: String Action Gauge - stewmac.com].
Shaping and polishing the nut
This looks good. We're ready to shape and polish this nut. I'm just knocking the sharp edges off. I'm going to put kind of a round to the front and back. You don't want to go lower than your string slots but you want a nice, smooth round feel to it.
And take some 320 and then some Micro Mesh Pads. I'll get the top looking how I want it. Then come back and blend the ends into it. Just two little dabs of fish glue on either end of the nut slot would be more than enough. Get it centered and use the strings to clamp it down.
You're done. That's it. Your string height is exactly where you want it.
