Fitting the nut in the IV kit

[Avi Ziv]

I am nearing the completion of my IV A kit and about to fit the nut. I bought a bone blank to replace the plastic piece that was provided.

When I look closely at the stop where the nut needs to go in, I see that the bottom is not flat. Half of is in the fingerboard plane and half is sloping in the headstock plane.

I've attached a rough sketch to illustrate what I see. It's somewhat exaggerated to make my point clear



Is this unusual?

I am wondering how to fit the nut. Here are my options as I see them

1. Carve the bottom of the nut to fit the geometry of the available "slot"
2. Lean the nut towards the headstock and live with a gap on the bottom near the fingerboard
3. Lean the nut towards the fingerboard and live with a gap on the bottom near the headstock
4. Fill the bottom angle and make the bottom of the slow all in line with the fingerboard

Any opinions? Ideas?

Thanks,
Avi

[Rick Lindstrom]

The front edge of the nut needs to be flush with the end of the fingerboard or you will have intonation problems.

Rick

[Avi Ziv]

The front edge of the nut needs to be flush with the end of the fingerboard or you will have intonation problems.

Rick

Good point! So that's my main constraint then. Now - should I perhaps deepen the nut slot until the bottom is flat? I'm a little worried about the bottom of the nut not being fully supported

Avi

[sebastiaan56]

I'd angle the bottom of the nut so that it fits properly against the end of the fretboard. If your drawing is to scale and the nut is too thin to sit against both the headstock and the fretboard I'd get some thicker nut material. This is important because when you tighten the strings the nut may move and ruin the intonation as Rick noted. Dont ask me how I know..

[Charles E.]

I hate to tell you this but it looks from your drawing like the fingerboard is not glued in the right place. Usually it goes up to the end of the flat plane and the nut is fit to the angled part.

[buddyellis]

With these kits your best bet is to flatten the slot with a file to be parallel to the top of the fingerboard. The fingerboard might not be 'exactly' in the right spot but it really doesn't affect anything (the scale length is still the same, and intonation is set with the bridge). Put a thin feeler gauge or something on the face edge of the fingerboard so you don't go filing into it, and use a square file to get the slot flat and wide enough for a nut. Won't take more than a few careful passes. I'd highly recommend tossing the kit nut and getting a proper piece of bone.

And no, it's not unusual for these kits. I'd say all 6 of the ones I've done were similar.

[Avi Ziv]

If your drawing is to scale and the nut is too thin to sit against both the headstock and the fretboard I'd get some thicker nut material.

The drawing is not completely to scale. The nut material is wide enough. The point I'm making is that the bottom of the nut slot is not flat. It straddles two planes

Avi

[Avi Ziv]

With these kits your best bet is to flatten the slot with a file. The fingerboard might not be 'exactly' in the right spot but it really doesn't affect anything (the scale length is still the same, and intonation is set with the bridge). Put a thin feeler gauge or something on the face edge of the fingerboard so you don't go filing into it, and use a square file to get the slot flat and wide enough for a nut. Won't take more than a few careful passes.

Buddy - I suppose that if the fingerboard was placed at the "correct" place, then the slot would be even but angled with the headstock, in which case I would have to file the bottom of the but at an angle - right?

So are you recommending to file the bottom of slot to be in the fingerboard plane or the headstock plane? I think there is a choice to be made here.

Thanks
Avi

[buddyellis]

Stewmac makes a file for this, too:
http://www.stewmac.com/shop/Nuts,_sa...ting_File.html

But you can get away with a normal square file if you're careful.

[Avi Ziv]

Stewmac makes a file for this, too:
http://www.stewmac.com/shop/Nuts,_sa...ting_File.html

But you can get away with a normal square file if you're careful.

Yeah - I saw that but I think I can get it done with a small square file, and protecting the end of the fingerboard - as you said

Thanks,
Avi

[Avi Ziv]

I hate to tell you this but it looks from your drawing like the fingerboard is not glued in the right place. Usually it goes up to the end of the flat plane and the nut is fit to the angled part.

Charles you are probably right. All these imperfect aspects of the kit are annoying but learning opportunities. That's how I'm viewing my first kit. The next one will be a more complete build (or maybe from scratch) and I'll be able to control it better

Thanks,
Avi

[buddyellis]

Buddy - I suppose that if the fingerboard was placed at the "correct" place, then the slot would be even but angled with the headstock, in which case I would have to file the bottom of the but at an angle - right?

On a martin guitar, this is certainly the case. But as for 'right'? It's really up to the builder. I can't see any technical reason for the slot to be on an angle and one reason for making it on the plane with the fingerboard: It's a heck of a lot easier to cut a square angle for the face of the nut than trying to guess that angle. Loars, I believe, were built with the nut slot on the plane with the fingerboard, not on an angle.

[buddyellis]

Here's the appropriate area from the 'Hogo' loar drawings:

http://www.mandolincafe.com/forum/at...1&d=1226271833

[Charles E.]

Buddy you are quite right, I have seen and installed nuts both ways. And I agree fitting a nut to a flat shelf is alot easier.

[Avi Ziv]

Ok - I filed the bottom of the slot flat in line with the fretboard and all seems to be well

Thanks for the advice!

Avi