# slotting a jazz bass nut

Discussion in 'Luthier's Corner' started by 59jazz, May 26, 2004.

1. ### 59jazzInfinite Rider on the Big DogmaSupporting Member

It's been years since I have used a jazz neck profile, So for my new project I chose a Moses jazz neck. I'm ready to slot the nut. Should I measure by string center, or string thickness? I will be using 105-50 flats. Is there a formula or popular measurement?

2. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
Yes, or yes. I believe some luthiers use equal center-to-center, while others use equal space between. It's been asked here before, but I couldn't find the thread.

Would the luthiers care to comment on which method they use?

3. ### Tim BarberCommercial User

Apr 28, 2003
Serenity Valley
Owner: Barber Music
I'm thinking standard Jazz string spacing is about 9.5mm between string centers at the nut. Could be wrong, tho, I don't have one here to check. As far as the equal centers vs. equal spaces thing, I think it comes down to personal preference. Both have their advocates, but on a 4-string I doubt there is much of a discernable difference.

I just ran out some quick numbers using assumed string gauges and overall spacing. For a 4-string, it looks like the variance in individual string placement would be less than 1 mm between the two methods. Somebody may want to check my math, though.

Overall spacing c-c 28.5 mm

E gauge 0.105" 2.667 mm
A gauge 0.090" 2.286 mm
D gauge 0.070" 1.778 mm
G gauge 0.050" 1.270 mm

equal centers 9.500 mm
E-A space 7.024 mm
A-D space 7.468 mm
D-G space 7.976 mm

equal spaces 7.489 mm
E-A center 9.966 mm
A-D center 9.521 mm
D-G center 9.013 mm

4. ### Hambone

Mar 18, 2000
Atlanta/Loganville
No need. Even if you erred by 50% (unlikely) it would only mean 1.5- mm.

I'm cool with your calculator skills

5. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
Here's a calculation for a 5-string set.

I do wonder what different luthiers do, as well as Fender and the other manufacturers.

If people find the difference in nut width between a J and a P to be significant, maybe this is an important aspect also? Maybe especially since this is the area of the neck where the left hand is in its worst posture, and where many of us spend the most time?

6. ### 59jazzInfinite Rider on the Big DogmaSupporting Member

Thanks for the good info guys! I saved the info in my folder, and will give it a try this weekend. Thanks for coming to the rescue!

H2

7. ### Hambone

Mar 18, 2000
Atlanta/Loganville
Hey Pilot - Put that chart up in the Shop Tips thread wouldja?

8. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
Glad to. Would you like an image, or an excel spreadsheet so people could enter values? And, is there any way that the attachment could be put against some other account quota, since mine is nearly full?

9. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
Also, would you like another one with my big string scale/pitch/gauge/tension sheet?

10. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
Here's the new, improved version of the spreadsheet- full nut layout, for 4-, 5-, 6-, and 7-string, equal centers and equal gap, mm and inch.

I'll post it here, and would a few people please try it out. After I fix any problems that are found, I'll put it in the tips thread.

11. ### Tim BarberCommercial User

Apr 28, 2003
Serenity Valley
Owner: Barber Music
Works well for me...good job pilot Where do I send the royalty checks?

[thinking out loud] to be consistent, wouldn't the equal-spaces method introduce some subtle asymmetries into the radial string array unless the bridge saddles were similarly compensated? [/thinking out loud]

12. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
N.C. (community service project) If somebody uses it in making a nice bass, all is good.
Quite true. It would have a gradual fade from equal-gaps to equal-centers, unless you also set the bridge for equal-gaps.

I'll add a note (for the final version) indicating that if the values for string-to-edge-of-FB are set to zero, then the sheet can be used to figure bridge spacing (including equal gaps).

There's also another method for bridges, the Anthony Jackson setup, which has equal distances between bass-side-edges of strings. I am not putting that in.

13. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
Revised version. Note added, error in string position fixed, formatted to be (hopefully) easier to understand.

14. ### Bass Kahuna

Dec 3, 2002
West Lafayette, Indiana
Luthier, Custom Builder
15. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
[mistake]Looks like a good tool for equal-centers spacing.[/mistake]

That is an interesting piece. My guess is that on a bass it would give somewhere between equal centers and equal gaps.

16. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
I'll add a note to the ss to the effect that by entering one-half the string guages, you can get a spacing that is halfway between equal-centers and equal-gaps. This looks like what the stewmac guage approximates.

I see it's been downloaded 5 times. Any more suggestions before I post it to the tips thread?

17. ### Tim BarberCommercial User

Apr 28, 2003
Serenity Valley
Owner: Barber Music
Nope, looks good. I plan to use it on the 6-string singlecut that I'm starting. Nice work!

18. ### frederic b. hodshonSupporting Member

May 10, 2000
Redmond, WA
Microsoft Product Designer
am i not seeing a cel variable for the nut width?

f

19. ### pilotjonesSupporting Member

Nov 8, 2001
US-NY-NYC
The nut width is a result. E.g. it comes up on the 4-string sheet in cells H17 and K17. (see comment on sheet)

I could make the nut width be an input. Then either the average string space, or one or both of the first/last-string-to-edge-of-FB cells, would have to become a result instead of an input. Can't overconstrain, er, no circular references I mean.

What do you think?

20. ### frederic b. hodshonSupporting Member

May 10, 2000
Redmond, WA
Microsoft Product Designer
them there are Pro/Engineer terms!!!

i'm currently setting up Pro/Engineer to create a guitar from user inputs.

i'm varying the nut width and the FB edge to string edge distances and letting the spacing fall where it may.

i'm almost done. it is called Pro/Program!!! i love it!

i'll write up a list of my variables when i'm done.

f