Cutting the Nut and Saddle Slots

[Soupy1957]

Do most builders (individuals or bulk-builders) follow the same guidelines for the width of the cuts they make in the Nut and Saddle of a mandolin? What size for each (gap) is typical?

[Bill Snyder]

Soupy,
I am not sure if this is what you are asking but, the width of the slot will be dependent on the gage of the strings used. A builder of F-style mandolins might cut his slots wider than the builder of bowlback mandolins.
You would want the slots 1 or 2 thousandths larger than the strings and cut with a rounded bottom.
If you are asking about space between the strings it will be the same at the nut and saddle for the pairs (ie the spacing between the two g's will be the same at the nut and saddle.) However, it will be greater at the saddle between the courses so that the strings follow the geometry of the fretboard.

[Soupy1957]

Not spacing.........string size cut......

Is there a typical F-Style range in the slot widths (string size).

This is a round-about way of discovering how far I'm willing to deviate in string sizes, regardless of type of strings.

I'm just trying to avoid going too small or too large on the strings I try out........too small, and I'll get buzzing.........too big and the strings would presumably not sit fully in the slot, and I'm not recutting em.

[Folkmusician.com]

I have not noticed any standard.

It is not uncommon for the mandolins to come from the factory with improperly cut strings grooves. In this case the strings are a poor fit to begin with. :)

[Paul Hostetter]

On the one hand you have the ideal, which is a slot that perfectly fits the string's diameter. But given that a mandolin may have a .010" or maybe a .012" string someday down the line when I'm not looking, I usually cut the slot for the .012" string. Anything narrower will work just fine.

http://www.lutherie.net/nutslot3.jpg

[Froglips]

After re-reading the OP, I realized what I had to say was not correct.

[Soupy1957]

Paul,
Ok, that covers the E string.....what about the rest?

[Bill Snyder]

Soupy,
Look at my response above. Cut them about 2 thousandths larger than the string and you should be ok. You will also have a little wiggle room to change to a heavier gage string set if you desire.

[Lefty Luthier]

I would add one minor detail that is important. Slope your grooves downwards on the tuner side so that your strings don't go over a sharp edge. This is especially important with pearl nuts due their tendency to chip from point loads.

[Paul Hostetter]

I shape the ramps on both the nut and the bridge to make sure the string contact is right at the edge where it needs to be and to be certain there's no chance of a string hanging up on a 'corner' or making questionable contact inside the slot.

As far as cutting the slots, there are nice ready-made tools, but I got real good at this several decades before Stew-Mac started selling them. In an earlier life I trained as a goldsmith and as a result I use jeweler's files of different sorts. I could cut all six slots for a normal guitar with the triangle file I use to do the high E strings, but that would be tedious, and I'd do it only because I could. I use a set of about five files, including a violinmaker's mousetail, to get everything from an .008 up to an .080.

[Soupy1957]

Thanks gang.........

[Rob Grant]

Soupy1957,

Look, if you stuff up or decide to go for a smaller string in a larger slot and you don't want to make a new nut you can always do the 'ol "backfill" with a bit of bicarb and a touch of superglue. If you use a filler like bone or pearl dust you usually have enough time to actually mould the slot with the string you're going to use.

[buckhorn]

i jjust finished cutting slots a a while ago...both are cut at the same width and depth....both are sloped away and the center coarces are tapered slightly at the nut towards the tuners....seems to me that it is easier to get the depth close then lower the hight of the nut , till it is about half the thickness of the string and the right hight off of the fret....keith