method for low action

ericmknight1906 · #1 08-31-2009, 04:52 PM

It's absolutely ridiculous that the action at the 3rd fret is 2mm and the action at the 12th fret can't get any lower than 5mm without fret buzz.

I'm sure that a lot of understand my frustration.

a while ago someone suggested placing half of a business card in the cavity under the bass of the neck in order to level the straightness (or angle if you will) of the fretboard. The goal is to try and get the action in the upper frets the exact same as the action closer to the nut.

I tried this method and it actually works

The result is approximately 2.5 mm action from the nut all the way up to the base of the neck.

Of course to get it absolutely perfect with no buzz, I had to raise the bridge saddles and sand down a couple of frets in some areas that were a knat's behind too high.

I am very pleased with the results.

Oh, and this method was done on my 5 string Squier P Bass 5 string(bolt on neck). The action is absolutely beautiful now.

(b)Assman · #2 08-31-2009, 05:43 PM

Along my quest for the perfect setup I did something similar. Shimming the nut is something a lot of people have come across in the search for low action. I used beer can metal, about 6 layers actually :P.

walterw · #3 08-31-2009, 11:53 PM

Quote:

Originally Posted by ericmknight1906

...The result is approximately 2.5 mm action from the nut all the way up to the base of the neck.

umm...2.5mm clearance at the nut (first fret, actually) would be hideously high action!

hold the string down at the first fret and look at the second fret; that's what you want it to look like at the first fret under the open string. you'll need proper files (or to get the nut properly filed) for that to happen.

having the action the same all the way up the neck is not how guitar necks work. the only way to do it is to have the nut, and thus the action at the lower frets, way too high!

Bassamatic · #4 09-01-2009, 12:08 AM

If you hold the string at the second fret, the action at the first fret should be about the thickness of a piece of paper. If the neck is straight and the relief is set correctly (truss rod adjustment) you should be able get the action at the 12th fret around 2-3mm.

Shimming the neck is necessary when you can't get the bridge saddles low enough. It tilts the neck back a degree or two. I did this on my MIM Jazz and it now has ridiculous low action. However, on a higher end bass, like my Cirrus and Lakland, you get this without shimming because it was made more precisely in the first place.

There are a lot of threads here about adjusting your action. Remember that the string vibrates most in the middle, so the neck must be slightly curved to match.

ericmknight1906 · #5 09-01-2009, 09:38 AM

Quote:

Originally Posted by walterw

umm...2.5mm clearance at the nut (first fret, actually) would be hideously high action!

hold the string down at the first fret and look at the second fret; that's what you want it to look like at the first fret under the open string. you'll need proper files (or to get the nut properly filed) for that to happen.

having the action the same all the way up the neck is not how guitar necks work. the only way to do it is to have the nut, and thus the action at the lower frets, way too high!

I stand corrected...from the nut to about the 6th fret the action is about 1.5 mm. it was initially about 2 but i filled a couple of the nut slots to get it where the strings barely clear the first fret wire when i i press down at the 3rd fret.

but from the 7th fret on up is about 2.5

lethargytartare · #6 09-01-2009, 08:08 PM

Gio S - +1

And I shim necks if the saddle screws are sticking out too much and mess with my right hand, so, purely for comfort (assuming I can still get a good setup, of course).

PBass101 · #7 09-01-2009, 08:28 PM

I shimmed both the front and back of the neck pocket. That way both ends are supported, unfortunately you'll need thicker shims in order to get the neck at the right height for low action. But I think it's better than just shimming the back of the neck pocket.

lethargytartare · #8 09-01-2009, 09:46 PM

You shim just the back of the pocket to change the pitch of the neck, and usually to improve the consistency of the action across the neck. Really, you shouldn't be lifting the neck to set action -- with two shims, you're reducing the neck-to-body contact, which isn't ideal, and you probably could have addressed the relevant problems with other adjustments.

Quote:

Originally Posted by PBass101

I shimmed both the front and back of the neck pocket. That way both ends are supported, unfortunately you'll need thicker shims in order to get the neck at the right height for low action. But I think it's better than just shimming the back of the neck pocket.