Lowering Action By Adjusting the Nuts?

Hi guys,
I want to lower the actions on my ukulele. So far, what I have seen online is sanding down the bridge bone. Do people also file down the depths of the 4 string slots on the nuts?
I have some ukuleles that look like the nut slots are quite deep, close to the fretboard, and their playability is superb. For the uke that needs some work, the nut is almost flat. I tried sanding down the bridge as well but wondering if I should also work on the nut.
Thanks in advance.

Ideally you want the string to protrude slightly from the nut rather than be buried in the groove (better tone). Thus, if you deepen the nut grooves, you should also grind the top of the nut so the string protrudes 30% or so. Also, to avoid strange buzzes and nasty overtones, the string should sit on the from edge of the nut groove and fall away 20 to 30 degrees towards the headstock.

Well yes you do need to address the string height at the nut too, since that actually has more of an effect on general playability than height at the saddle. But adjusting the height at the nut is rather more difficult than at the saddle (or bridge). I would start with taking a look at the uke with superb playability, and measure height of the strings above the first fret - using feeler gauges is probably the easiest approach. What you are shooting for is about 0.5 mm (~0.020") or less. Then measure this same distance with the uke that needs work and see how much higher the strings are. Once you have decided you need to lower the height at the nut you are either going to have to file the nut slots deeper, or remove the nut and sand away from the bottom. Filing the slots sounds easy, but it takes special files to do a good job, and if too much needs to be removed can take a long time. Sanding away the bottom of the nut can be faster, but here you have to be careful about the condition of the slot underneath the nut and to get everything square. If all this sounds like a bit much, then your best bet is to get a tech to do the work for you. But if you do seek help it would still help to know what type of height you like so you can tell the tech what you want the result to be.

Also note that the depth of the nut slots is not really an important factor, only the gap between the top of the first fret and the bottom of the strings matters. If one nut is mostly flat on top that just means that very little work has been done on it. The ideal nut has slots whose depth is only about half the string diameter, as any more just causes binding. So your good uke plays well because the nut height has been adjusted, not because the slots are deep (if that makes sense).

The trick is to get the action "just right" without messing with the intonation. From my experience working on the nut gets the action lowered without impacting the intonation, however that hasn't been the case when when lowering the saddle.

If one plans to lower both the saddle and nut slots to get better action, suggest doing the saddle first. If the nut is done first, it's odds-on that lowering the saddle afterwards may result in string-fret contact on the first two frets. Then, it's necessary to shim up the saddle or replace the nut.

Also, when working on a uke's action, it's good to check the intonation before, during and after. It only takes a few seconds to do so, but can save one from major frustration later,

Thanks guys. I have already sand down the saddle a little bit but it doesn’t looks it it’s affecting anything. That’s why I am thinking about doing it at the nut slots

Where is it too difficult to play? Nut adjustments mainly impact the string height on the first 3 or 4 frets. If it's difficult to play higher up, you need to work on the saddle. If you're a soft finger style player, you can set the saddle height over the 12th fret on the 4th (G) string to about 2.5mm (measured from the top of the fret to the underside of the string). If you pluck on the loud 'n hard side, you may need 2.75mm or even 3mm (my fav). Put a ruler against the 12th fret and press the 4th string down near the saddle and you can roughly gauge how much the saddle needs to come down. Once you know how much to shave off, measure and mark the saddle, put it in a vice and use a file to cut it down.

Often times these thread titles are just hilarious.

I thought about making a comment about avoiding skinny jeans but then, yeah...

gochugogi said:

I thought about making a comment about avoiding skinny jeans but then, yeah...

Click to expand...

Yes, the possibilities are endless, but better left unsaid.

gochugogi said:

Where is it too difficult to play? Nut adjustments mainly impact the string height on the first 3 or 4 frets. If it's difficult to play higher up, you need to work on the saddle. If you're a soft finger style player, you can set the saddle height over the 12th fret on the 4th (G) string to about 2.5mm (measured from the top of the fret to the underside of the string). If you pluck on the loud 'n hard side, you may need 2.75mm or even 3mm (my fav). Put a ruler against the 12th fret and press the 4th string down near the saddle and you can roughly gauge how much the saddle needs to come down. Once you know how much to shave off, measure and mark the saddle, put it in a vice and use a file to cut it down.

Click to expand...

The 1st and 2nd frets are very hard to press down

gochugogi said:

I thought about making a comment about avoiding skinny jeans but then, yeah...

Click to expand...

I found a post on the forum called “ sanding my nuts” lol

OP, you need to make actual measurements. Typically you'll need to measure and adjust string height above the frets at the first fret (adjusted by the nut slots) and at a fret further down, maybe the twelfth. If I recall correctly the usual sequence is to adjust the string height at the nut first then at the saddle.

Go get some feeler gauges and use them; don't just sand and file stuff hoping to make it better.