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View Full Version : Lower the Action on an Ukulele Nut



zztush
12-17-2017, 10:46 PM
Action on the ukulele is personal preference, therefore it is often set up bit higher. I always set them bit lower when I buy ukuleles. Here I explain how I lower the action.

The figure left below shows good and bad shapes of grooves. Good shape is semicircle and bad shape is deep groove. If we just cut the grooves, they become deep groove (B in the right figure). Then we need to sand the top of the nut (red line on C). This is messy. Hence we just sand on the bottom(D) instead.

https://s13.postimg.org/snr0qv5yv/image.png (https://postimages.org/)

The work is very easy. Remove the nut first (see the left figure below) with your thumb. We don't need hummer, thumb is enough. Then sand the bottom. Sanding is not too difficult but we should be careful because the nut is not easy to pinch. We need to check the level of bottom many times. We can use folded sand paper for grooves (see the right figure below). I don't use glue for nuts afterwards. My nuts are all replaceable like saddle. I have some ukuleles which have two nuts, one is high G and one is low G.

https://s13.postimg.org/u42j8ugjr/image.png (https://postimages.org/)

Hi, Dave and Jarmo_S! Use cattle bone nuts. It produce men's smell when sanding. Ukulele nuts and our nuts smell same.

Louis0815
12-17-2017, 11:50 PM
Good shape is semicircle and bad shape is deep groove.Again, you postulate things without giving the slightest bit of explanation..... Would you pls be so kind and explain why a deep grove is to be considered bad in your opinion?

Besides that IMHO you forgot the most important thing about sanding: make sure you sand off absolutely in parallel, otherwise you'll end up with different action on the different strings. And/or you change the "breaking point" which could affect overall intonation.

[OffTopic]

I don't use glue for nuts afterwards. My nuts are all replaceable like saddle.
[...]
Ukulele nuts and our nuts smell same.Well, that's probably too much information.....

Jarmo_S
12-18-2017, 12:51 AM
I also don't understand OP's opinion of deep slots being bad. They can even protect strings from collisions.

Anybody's sexual preference are their own and I don't judge. Except here i must say being quite normal person, because that too much information OP gave might give some false information to readers.

zztush
12-18-2017, 01:23 AM
Hi, Jarmo_S! Thank you for the question!

Actually one of the most important thing of the groove is that the strings can move very smoothly in the nut groove when playing. This is related to the scale. When Eric Clapton bends first string (see the figure below), the string extends not only within the green line but also the red line. It requires smooth groove. Hence our grooves on nuts are made semicircle shape instead of deep groove on guitars and ukuleles. This string move happens not only bending but also any fingering. And the real scale is seen by red line instead of green line.

https://s13.postimg.org/8grd3kmuv/image.jpg (https://postimages.org/)

Ukecaster
12-18-2017, 01:50 AM
Before changing the nut, how do you determine if it is too high? If the goal is to lower the action, should you start at the nut, or saddle? I've seen where, on guitar, you push and hold a string down at second or third fret, then judge the gap between string anf fret, at 1st fret. It should be a gap that allows a business card to easily slide in. If more than that, the nut can be shaved on the bottom. Is this applicable to ukes?

zztush
12-18-2017, 03:18 AM
Hi, Ukecaster! Thank you for asking and I just write my experience.

Before changing the nut, how do you determine if it is too high?
I check playability first. Then check the nut hight by the method you wrote, and the saddle hight on the 12th fret (about 2.6mm).
If the goal is to lower the action, should you start at the nut, or saddle?
I start with higher side. If both very high, I start with saddle. Because it is easier for me.
I've seen where, on guitar, you push and hold a string down at second or third fret, then judge the gap between string and fret, at 1st fret. It should be a gap that allows a business card to easily slide in. If more than that, the nut can be shaved on the bottom. Is this applicable to ukes?
Yes. I set both nut and saddle hight same as guitar. I check same way as you wrote for nut and It should be far less than business card and very near to zero for me. I apply it guitars too. And the saddle hight on the 12th fret is about 2.6mm. It is same as guitars too. Thicker strings requires more hight than thinner ones.

Inksplosive AL
12-18-2017, 08:11 AM
When we explain things we need to simplify and define everything for they laymen. Those diagrams to me complicate things quite a bit, as does your explanation of the slots being too deep. If they are filed properly they shouldn't be too deep.

Now I'm no luthier but I do fine work with my hands. A properly files nut slot is filed at an angle towards its strings designated tuner. This site explains it better than I ever could. www.lutherie.net/nuts.html This is a site that I myself learned much from a few years back.

Some of this was touched on in my old thread http://forum.ukuleleunderground.com/showthread.php?89687-Blueprinting-Smiley!&highlight=blueprinting+smiley

Tootler
12-25-2017, 01:51 AM
The way to check if the nut needs filing is to make sure your uke is in tune then check the intonation by fretting at the first fret. If the note is sharp, then the nut is too high because the string has to be stretched too much when you press it onto the fret wire. Check for each string.

I don't see why the OP's lower LH diagram is necessarily wrong. My Brueko ukuleles have hardwood nuts rather than bone or plastic and the nut has slots rather than grooves or semicircles for the strings to pass through and I have no problems with tuning or with strings breaking as the slots are wide enough for the strings to pass through comfortably but not so wide as to be sloppy. If you do have something like the OP's diagram B then make sure you sand the sides smooth.

I've made nut slots deeper with a fine file. Detune the string, lift it out of the nut and rest it beside the slot, gently file a little, put the string back in, bring up to tune and check intonation by fretting at first fret. Repeat until the string is in tune when you fret at the first fret. It's very much a matter of a little at a time. You can always take a little more off. It's much harder to put back on. It can be done with bicarbonate and super glue but better not to have to do it. Engineers have a maxim: "Measure twice, cut once". Bear that in mind.