Need to set up my Cordoba Tenor

bobhost

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My dear wife has been listening. For Christmas she got me a Cordoba Tenor 15TM, decent enough for me, and a set of low g strings, D’Addario fluorocarbon. While stringing up the low g I knew that the nut slot would need to be wider, which was easy enough to do with a small file.
But all of the action is too high, both ends all 4 strings. .9mm at the first fret and 3.1mm at the 12th fret. If I am going to be lowering the nut, I want to use proper tools.
General googling says that Stewmac files are the right choice. I am getting a few extra sizes since I have soprano through tenor (now with low g) instruments that might need attention in the future.
I have watched several videos on the setup and I think I will start with the nut. It is clearly too high.
I will take it slow and try it in small steps.
The slot will be slightly angled back so that the string break is at the front of the nut.
My target is probably 2.7mm at the 12th and I-dunno at the first. My professionally set up ukes will hold a piece of paper under the first fret when the string is pressed at the third. This tenor will not hold a business card. At least I want it close enough to hold a business card.
Am I headed in the right direction? Any omissions or inaccuracies in my plan?
 
:)
I have also done this and the nut is much too high.
My other ukes will hold a piece of paper between the first fret and the string when the string is fretted at the third.
This new tenor has a much larger gap, and will not hold a business card between the string and first fret during the same test. The business card can even move up and down.
Good to know that you agree that this test is a good one to use.
 
My dear wife has been listening. For Christmas she got me a Cordoba Tenor 15TM, decent enough for me, and a set of low g strings, D’Addario fluorocarbon. While stringing up the low g I knew that the nut slot would need to be wider, which was easy enough to do with a small file.
But all of the action is too high, both ends all 4 strings. .9mm at the first fret and 3.1mm at the 12th fret. If I am going to be lowering the nut, I want to use proper tools.
General googling says that Stewmac files are the right choice. I am getting a few extra sizes since I have soprano through tenor (now with low g) instruments that might need attention in the future.
I have watched several videos on the setup and I think I will start with the nut. It is clearly too high.
I will take it slow and try it in small steps.
The slot will be slightly angled back so that the string break is at the front of the nut.
My target is probably 2.7mm at the 12th and I-dunno at the first. My professionally set up ukes will hold a piece of paper under the first fret when the string is pressed at the third. This tenor will not hold a business card. At least I want it close enough to hold a business card.
Am I headed in the right direction? Any omissions or inaccuracies in my plan?

The only thing I see that you have not mentioned is protecting the uke while you work on the nut. It is distressingly easy to file an unwanted notch into a fret or a tuner capstan or even the headstock itself while you've got all your attention focussed on filing the nut. When I work on the nut, I slip a thin steel protector under the strings .. I use a blunted cabinet scraper. Masking tape won't stop a file but your choice of materials to protect the headstock is limited.
 
Got my set of files and string picker. But my order for the string height gauge is delayed. I think that I will wait for that so that I can measure the before and after more accurately.
IMG_9937.jpg
 
And good tips about protecting the headstock. I will have to look for something to put there.
 
I recently set up my Cordoba 21T, and you really do not need a guage to work on the nut. Just file a little at a time until you feel a slight drag on a piece of paper at the first fret while holding the string down at the third fret.

I used some Swiss files I already owned, and as I got close, finished with a welding tip cleaner, which I also already had.

Having been successful with the Cordoba, I did it again on a VTAB concert, and was totally happy with the results. I also lowered the saddle on both to a little under 3mm, but I am waiting for a string height guage I ordered to arrive before going any further.

It appears that almost all of the mass produced ukuleles coming from China will require a little work to make them play well, but considering the low cost, I think it's worth doing.

I now have three ukuleles in different sizes, and the only one I didn't work on is a Flight Travel soprano, which with the exception of the top is all plastic, and the string height is baked in. Having a zero fret reliably sets the strings at the nut to a nice playing height.
 
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I recently set up my Cordoba 21T, and you really do not need a guage to work on the nut. Just file a little at a time until you feel a slight drag on a piece of paper at the first fret while holding the string down at the third fret.
I am much higher than that at the nut currently. But since I have one on order, I will hold off hacking until it gets here.
I am waiting for a string height guage I ordered to arrive before going any further.
Me too. While I would love to have the machined brass one offered by Stew-Mac, I opted for a less expensive one from ebay. I expect more consistent readings that trying to hold my micrometer perpendicular to the fingerboard.
It appears that almost all of the mass produced ukuleles coming from China will require a little work to make them play well, but considering the low cost, I think it's worth doing.
And this is going to let me set it up the way *I* like.

Thanks for the input!
 
And good tips about protecting the headstock. I will have to look for something to put there.

Blue masking tape layered up works OK but you need to keep your eyes on it because you can file through it pretty quickly
 
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Nobody has yet mentioned the effect on string height at the nut on intonation.

I've learned from some of my friends that do their own setups, will use a feeler gauge between the nut and first fret, on the wood flush to the nut, to protect the fretboard, and then a small piece of plastic taped to the headstock between the nut and tuner shafts to protect the headstock.

Then they file the specific slot in question just 2-3 strokes, remove the feeler gauge and replace and retune that string, and then check intonation on the 1,2,3,4 frets with the tuner vs. the open string. Also keeping in mind checking for string buzz.

If the string registers the note too sharp, then they replace the feeler gauge, and rinse and repeat.

This is done for each string. It takes a while to get it dialed in (I have observed the process many times, but not needed to do this myself on my concert Flea since it has a zero-fret).

The problem is that any arbitrary measurement is likely to be skewed if applied to a variety of instruments, which may have varied fret thickness from uke to uke from different makers, meaning the height of the fret itself, and saying that 1mm or 1.25mm is the "perfect' string height on the first fret, when fretting the third fret is a slippery slope.

If you go by intonation (as low as possible in the nut slots, before getting string buzz), it seems to me that you are more likely to be going as low as possible and keeping the instrument in tune, with proper intonation, which is completely missed if you only do this process by geometry.

However, this is not an absolute or mandate, just something I have observed myself.
 
Joe, you are right about the intonation. While I intend to lower all the strings, it is my low G that makes my ears hurt the most. When I play an A at the second fret, I cringe. It is noticeably sharp. I am waiting on the string height gauge to start. Since I might introduce buzz if I take off too much, I want to know what my target should be with the replacement nut. I am still going to take very small adjustments with multiple iterations, as you and many others have suggested.
 
... If you go by intonation (as low as possible in the nut slots, before getting string buzz),.

How "low" can you go before you get string buzz? How do you know when to stop? if you got the buzz, you know that you went too low, but then you messed it up, already.

This is one of my major uncertainties when I've tried to do this myself (with my cheap ukes).

Thanks

Eugenio
 
I do not see the need to replace the nut if you have gone too far.

You can just fill the slot a bit and start over. Here is how to do it.

Use masking tape across both ends of the slot like a pair of dams, then fill the slot with baking soda. Carefully apply 1 or 2 drops of thin super glue. It will start a reaction and in a few moments it will be hard as a rock! You can then remove the tape and start filing again. You do not need to fill the slot to the top if you only need a small correction. Just make sure that the baking soda is level.

This method works well to change the string spacing by filling the slots completely.

The color of the baking soda is almost the same as the bone nut.

It's easy to do.
 
Thanks for the tip dcuttler! I will still take very small steps, but will less worry, knowing there is another avenue to success after buzz failure.
I did receive the gauge from Stew-Mac. I have done a series of measurements at the first fret and at the 12th (I know, that gauge is less accurate at the 12th since the weight of the plunger changes the readings) But I wanted to get some kind of reading.

Code:
	Inches			MM	
	Fret				
String	1	12		1	12
A	0.034	0.110		0.864	2.794
E	0.033	0.110		0.838	2.794
C	0.035	0.112		0.889	2.845
G	0.039	0.116		0.991	2.946

Now to make some time and work up the nerve to start filing.
 
Thanks for the tip dcuttler! I will still take very small steps, but will less worry, knowing there is another avenue to success after buzz failure.
I did receive the gauge from Stew-Mac. I have done a series of measurements at the first fret and at the 12th (I know, that gauge is less accurate at the 12th since the weight of the plunger changes the readings) But I wanted to get some kind of reading.

Code:
	Inches			MM	
	Fret				
String	1	12		1	12
A	0.034	0.110		0.864	2.794
E	0.033	0.110		0.838	2.794
C	0.035	0.112		0.889	2.845
G	0.039	0.116		0.991	2.946

Now to make some time and work up the nerve to start filing.

Based on those numbers you do indeed have a way to go. Just take it slow at the nut.

Here are some tips on setups that I posted here last year. Be sure to check your frets for high spots too. If you don't already have a fret rocker that would be a good tool to add to your kit.






I’ve been doing setups on my guitars for many years, and I thought I would share a couple of hints that may help those of you who would like to work on your own ukes.

The steps of an acoustic guitar setup are usually given as: 1) adjust truss rod to set relief, 2) adjust string height at the saddle, 3) adjust string height at the nut, and 4) adjust intonation at the saddle. Life is a bit more simple with ukes as there is rarely a truss rod, and most saddles are not compensated for intonation. So with a uke we mostly just care about string height at the nut and at the saddle.

As on a guitar I would start with adjusting the height at the saddle. But before doing that I would first measure the action at the nut. That’s because lowering the string height at the nut will affect action at the 12th fret too. If for example the action is 0.040” at the first fret, and you lower it to 0.020”, that would bring the action at the 12th fret down by half the difference, or 0.010”. If you set the action at the saddle first without keeping this in mind you could overshoot and be too low when finished. The usual way to measure this string height at the first fret is with feeler gauges. But if you’re a tool geek like me you could also invest in a nut slotting gauge which really makes these measurements easy.

Nut_Slotting_Gauge.jpg

http://www.stewmac.com/Luthier_Tools/Tools_by_Job/Tools_for_Nuts_and_Saddles/Nut_Slotting_Gauge.html

And for measuring string height at the 12th fret I use:
16cba9f2fd8f67fccad9ffbed7a22a16.jpg


My target for action at the first fret is about 0.020”, and my target at the 12th fret is about 0.085”. So if I know I have to later lower the action at the nut by say 0.010”, I will target the saddle to give a string height at the 12th fret that is greater by half that difference, or in this case a preliminary target of 0.090” to eventually wind up at 0.085”.

You might wonder why not just set the action at the nut first? You can, but again you have to think about the effect of changing things at the other end. With a little geometry you can show that the action at the 12th fret is reduced by 50% of whatever change you make at the saddle, while that at the first fret is reduced by 5.6%. That is, if you reduce the saddle height by say 0.070” that will drop the string height by 0.035” at the 12th fret, and by 0.004” at the first fret. That 0.004” is not a lot, but it could be enough to cause a string to buzz on the first fret if you set it really low at the start.

So how do you adjust the saddle height? The common method is to draw a pencil line on the side showing how much to remove. In my example above the uke arrives with a 3.0 mm, or 0.120” string height at the 12th fret, and I want to lower it to 0.085”, so I need to remove twice 0.035” at the saddle, or 0.070”. You then sand the saddle across a flat surface (such as a granite tile) with the side of the saddle up against a block to keep the bottom square. This does work, but it’s really easy to mess it up and go too far, or to get an uneven bottom surface. And what if you want to take more off one end of the saddle than the other? I’ve seen several ukes where the string heights were not even, and I needed to remove more from one end of the saddle than the other. Doing that freehand is especially challenging.

Fortunately there is something called a sanding jig that makes this a breeze to do. I first saw a homemade one years ago called the Dickey Saddle Sanding Jig.

http://www.dickeyguitars.com/dickeyguitars/Saddlesand.html
saddlesand.JPG


You lightly clamp the saddle in the jig, then elevate the sides of the jig by the desired amount to be removed, push the saddle all the way down, and tighten. If done correctly you now have just the amount of the saddle to be sanded away sticking out proud of the jig. You then sand away until the block hits the sandpaper, and you’re done. The bottom is perfectly smooth, flat, square, and of the correct height. For the measurement you can use sheets of paper or business cards, anything that stacks to the proper height. And best of all is that you can switch things around to elevate one end more than the other before you tighten the jig. Say take 0.050” off one end, and 0.030” off the other.

You can make one of these for just a few dollars. Or…if you’re like me and love tools, you can buy one readymade – the Saddlemaster Saddle Sanding Jig.
 
I have been putting this off because I am afraid of introducing buzz. Or worse.
But I guess a new nut (or baking soda and CA) can fix that.
Prepped for surgery. I picked .027" as a target string height at the first fret.
I'll let you know how it goes.
prepped.jpg


prepped.jpg
 
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I took all 4 strings down to .027" at the first fret.
Then I banged on it, playing hard. No indication of a buzz.
It still had a slight bit of intonation problems where the first and second fret are sharp. Actually, some of the strings stay sharp all the way up the fret board, but I will tackle that when I lower the saddle (and think about compensating)
But while I had all the tools out, i lowered to .025" and then .024". I think that the intonation is slightly better at .024" but to be truthful, I could just be imagining it. unless I had them side by side, I am probably applying wishful thinking as much as anything.
But there is no doubt that this is much better than how it came from the factory.
Encouraged, I also made adjustments to the nut slots on my Cordoba concert, with similar results. Improved intonation. Still needs work at the saddle.
Thanks for all the help so far.
 
My cheap ebay string height gauge arrived about a week ago, and I measured the height of the strings on my VTAB concert, which I had previously lowered the action, and was satisfied with. The height at the 12th fret is 2.5 mm. At the present time I am happy with the way it plays, so I am not going to take it any lower.

As for intonation, there can be so many variables that I think you could end up chasing phantoms. Every time you change to a different brand or diameter of strings, the intonation can change too. I am willing to accept some variation and tune to get a reasonable average up and down the neck.

It's easy to obsess over this stuff.
 
It's easy to obsess over this stuff.
I don't know any other way to do it! ;-)

But I am paying more attention to the intonation of my instruments. I had not payed much attention to it until I started finger picking and playing further up the neck.
I can play chords just fine. Every once in a while a chord is even up to the 6 or 7th fret.
But with my finger picking, I might play a string up the board along with an open string. After hammering out the mechanics of the finger positions, My ear tole me I was being sloppy (which I often am). So I slowed down and made sure I was fingering without excessive push. Not bending the string sideways. Finger near the upper fret. And it still sounded off.
The changes I have made at the nut have this reduced a fair bit.
 
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