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  #16  
Old 12-01-2019, 11:10 PM
mirwa mirwa is offline
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Its actually repairable with those measurements

You have as indicated - good relief at 6 thou, reversing your nut height I would say you have around 12 thou over the 1st fret when holding string down between 2nd and third, so you could lower your nut height just a tad more say 6-7 thou

string height over the body with respect to action height at 12th indicates yes neck angle is not the greatest and being a spanish heel tricky to repair (not impossible)

To get your string height down to say 2.5 mm (100 thou ish), I reckon take the nut down another 5 thou (ish) and then the saddle will need too come down 2.2mm in thickness (88 thou).

That is the mathematics of it, so if you are to lower the saddle height by 2.2mm your going to need to remove a fair amount of the bridge itself, say thin the top of the bridge down a good 2.5mm which may necessitate the saddle slot to be lowered internal to the bridge to prevent break out, you currently have a good 6mm of wood under the saddle

If you go this path 9.5mm ish will be the final string height over the body - so not too bad

Alternative - cut the neck off and turn it to a bolt on, or remove frets and plane the board at an angle or remove board and add a tapered shim full length and refit

Steve
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Last edited by mirwa; 12-02-2019 at 04:29 AM.
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  #17  
Old 12-02-2019, 06:23 AM
Quickstep192 Quickstep192 is offline
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What tool(s) would you use to deepen the saddle slot to ensure that the bottom stays flat?
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  #18  
Old 12-02-2019, 07:37 AM
mirwa mirwa is offline
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Simplest is just a file, stewmac sell specialty files but ones from hardware stores work fine.

I personally use an overhead router, i strap the guitar down and with a hand controller move the router as required

Steve
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  #19  
Old 12-02-2019, 08:41 AM
Quickstep192 Quickstep192 is offline
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Quote:
Originally Posted by mirwa View Post
Simplest is just a file, stewmac sell specialty files but ones from hardware stores work fine.

I personally use an overhead router, i strap the guitar down and with a hand controller move the router as required

Steve
I was thinking about a router with a guide - still trying to figure out how to make a super accurate guide. Any suggestions are welcome.
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  #20  
Old 12-02-2019, 08:56 AM
Skarsaune Skarsaune is offline
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Take a look at StewMac's jig for some ideas....

https://www.stewmac.com/Luthier_Tool...uting_Jig.html
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  #21  
Old 12-03-2019, 02:38 AM
nikpearson nikpearson is offline
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Default Are you saying take the action to 2.5mm?

Quote:
Originally Posted by mirwa View Post
Its actually repairable with those measurements

You have as indicated - good relief at 6 thou, reversing your nut height I would say you have around 12 thou over the 1st fret when holding string down between 2nd and third, so you could lower your nut height just a tad more say 6-7 thou

string height over the body with respect to action height at 12th indicates yes neck angle is not the greatest and being a spanish heel tricky to repair (not impossible)

To get your string height down to say 2.5 mm (100 thou ish), I reckon take the nut down another 5 thou (ish) and then the saddle will need too come down 2.2mm in thickness (88 thou).

That is the mathematics of it, so if you are to lower the saddle height by 2.2mm your going to need to remove a fair amount of the bridge itself, say thin the top of the bridge down a good 2.5mm which may necessitate the saddle slot to be lowered internal to the bridge to prevent break out, you currently have a good 6mm of wood under the saddle

If you go this path 9.5mm ish will be the final string height over the body - so not too bad

Alternative - cut the neck off and turn it to a bolt on, or remove frets and plane the board at an angle or remove board and add a tapered shim full length and refit

Steve
2.5mm is far too low for a nylon string instrument even with the highest tension strings available.

I’d really caution against doing anything other than optimising the string heights at the nut. Your neck relief is good, the string height above the soundboard is good; lowering the saddle significantly will necessitate removing wood from the bridge and will bring the string height above the soundboard below what most makers think is the optimum. You could end up ruining the sound of your guitar. As to removing the neck completely to correct the geometry; that has to be overkill.

From the measurements you’ve given your guitar has a good setup for nylon strings other than perhaps some minor tweaking at the nut. When all is said and done the instrument has to play well and sound good.

One suggestion which would cost little and may improve playability: try some different strings. What do you have on the guitar now? Using lower tension strings should make for better playability and may even bring the action down a wee bit.
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  #22  
Old 12-03-2019, 03:03 AM
mirwa mirwa is offline
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Quote:
Originally Posted by nikpearson View Post
2.5mm is far too low for a nylon string instrument even with the highest tension strings available.
I learnt quiet some time back, there is no such thing as too low of an action, it is whatever is comfortable to the player.

The action is too high for the OP's comfort, this necesitates it needs to be lowered, I do concur that he may not need it as low as 2.5mm

I have however set many many classicals at 2.5mm and even lower.

Steve
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Last edited by mirwa; 12-03-2019 at 03:15 AM.
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  #23  
Old 12-03-2019, 08:38 AM
Quickstep192 Quickstep192 is offline
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Quote:
Originally Posted by nikpearson View Post

I’d really caution against doing anything other than optimising the string heights at the nut. Lowering the saddle significantly will necessitate removing wood from the bridge and will bring the string height above the soundboard below what most makers think is the optimum. You could end up ruining the sound of your guitar. What do you have on the guitar now? Using lower tension strings should make for better playability and may even bring the action down a wee bit.

A question on these points -

If I remove wood from the bridge and lower the saddle and don't like the result, isn't the worst case scenario that I make a new, taller saddle to get string height back to where it is now?

I currently have low tension basses and med-hi tension trebles. My concern is not so much about difficulty in fretting the strings as it is that the distance to the fingerboard doesn't "feel" right, especially further up the neck.
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  #24  
Old 12-03-2019, 09:55 AM
John Arnold John Arnold is offline
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Considering your saddle measurement is the full saddle (5mm), I don't think you need to worry too much about deepening the slot. The rule of thumb is that at least 1/2 of the total saddle should be in the bridge. I would lower the saddle and bridge 1mm to 1.5mm. That would bring your 12th fret action down to 3mm or a bit lower.
2.5 mm may work for some nylon string players, but can be buzzy for some with a strong attack.
Your nut can be lowered a bit. Press the string on the second fret and check clearance over the first fret. It should be minimal. Ideally, the nut can be the same height as the frets, but in practice, it is usually set very slightly above. With the nut height the same as the frets, action over the first fret will be about 11% of the 12th fret action.
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  #25  
Old 12-03-2019, 10:39 PM
nikpearson nikpearson is offline
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Default Fair point.

Quote:
Originally Posted by Quickstep192 View Post
A question on these points -

If I remove wood from the bridge and lower the saddle and don't like the result, isn't the worst case scenario that I make a new, taller saddle to get string height back to where it is now?

I currently have low tension basses and med-hi tension trebles. My concern is not so much about difficulty in fretting the strings as it is that the distance to the fingerboard doesn't "feel" right, especially further up the neck.
That’s a valid point. The amount of wood you’ll need to remove probably won’t in itself make a significant difference to the sound; the weight of a bridge can be quite critical though. So yes, you could restore the current action by putting a higher saddle in.
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