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  #1  
Old 01-30-2020, 08:35 PM
cliff_the_stiff's Avatar
cliff_the_stiff cliff_the_stiff is online now
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Default Basic Truss Rod Adjustment Question

Hello AGF.
First off, I am impressed regularly by the respectful communications I read here. Thank you for being a good group.

Is my following statement correct?

Generally, starting with an appropriately adjusted truss rod for the current string tension; when adjusting a truss rod, either from the head or from the sound hole, we tighten the truss rod if we are increasing the string tension; and therefore also are loosening the truss rod when applying lighter string tension.
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Old 01-31-2020, 03:21 AM
jazzizm jazzizm is offline
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Yes.

You should measure neck relief though. Should be about 1/32“.
Or you can: capo 1st fret, finger on the fret where neck meets body, tap other finger on string at 7th fret. If there’s barely a visible gap and there’s a „click“ from string contacting fret, relief is about correct.
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Old 01-31-2020, 04:09 AM
Silly Moustache Silly Moustache is offline
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Quote:
Originally Posted by cliff_the_stiff View Post
Hello AGF.
First off, I am impressed regularly by the respectful communications I read here. Thank you for being a good group.

Is my following statement correct?

Generally, starting with an appropriately adjusted truss rod for the current string tension; when adjusting a truss rod, either from the head or from the sound hole, we tighten the truss rod if we are increasing the string tension; and therefore also are loosening the truss rod when applying lighter string tension.
Actually, it isn't about string tension, it is about the straightness and/or bow of the fretboard.

A completely flat fretboard usually causes buzzes when the strings are played and bounce against the frets.
Therefore there needs to be a slight bow in the fretboard to allow for this.

The truss rod works between the first fret and the 12th/14th fret (at most).

The amount of bow depends on the set up, the action and how hard you play, but it is best measured half way between the fist fret (use a capo) and the fret that coincides with the body join.

I play mostly (but not exclusively) Collings, and they recommend .005". i prefer a little more - about .007-8"

With the capo on 1st fret and holding down the string (1st or 6th) at the 12th/14th, measure the space between the 7th fret and string with a spark plug feeler gauge tool.

see this :

Hope this helps
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Old 01-31-2020, 08:30 AM
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Thank you for the answers. Reinforced my understanding some.
Silly Mustache, thanks for the video, I should have known that you would have something precisely for what I asked.
My action is perfect, Im moviing to a lighter string for a while and want to keep the set up...
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Old 01-31-2020, 12:06 PM
Silly Moustache Silly Moustache is offline
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Quote:
Originally Posted by cliff_the_stiff View Post
Thank you for the answers. Reinforced my understanding some.
Silly MOustache, thanks for the video, I should have known that you would have something precisely for what I asked.
My action is perfect, I'm moving to a lighter string for a while and want to keep the set up...
All part of the service sir!
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I'm here to try to help and advise and I offer one to one lessons/meetings/mentoring via Zoom!
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Old 01-31-2020, 12:33 PM
Howard Klepper Howard Klepper is offline
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Quote:
Originally Posted by cliff_the_stiff View Post
Hello AGF.
First off, I am impressed regularly by the respectful communications I read here. Thank you for being a good group.

Is my following statement correct?

Generally, starting with an appropriately adjusted truss rod for the current string tension; when adjusting a truss rod, either from the head or from the sound hole, we tighten the truss rod if we are increasing the string tension; and therefore also are loosening the truss rod when applying lighter string tension.
Do not automatically change the truss rod adjustment when you change string gauge. Change it when the relief is not ideal. "Ideal" depends on strings and playing style. For the great majority of players it will be between about .003" and .007". The suggestion above of about 1/32" (.031") is way too much for anyone.
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Old 01-31-2020, 01:21 PM
jazzizm jazzizm is offline
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Sorry, I got confused by the imperial system.
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Old 01-31-2020, 03:10 PM
John Arnold John Arnold is offline
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While a flexible neck may need an adjustment when changing to lighter gauge strings, a stiff neck may not need any adjustment at all. Neck stiffness is dependent on several factors, including stiffness of the wood used, neck thickness, width and length, as well as the type of reinforcement. Action height is also a factor.....higher action affects the neck relief more than lower action.
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Old 01-31-2020, 07:58 PM
Howard Klepper Howard Klepper is offline
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Originally Posted by jazzizm View Post
Sorry, I got confused by the imperial system.
No problem. It's not like you crashed a spacecraft on Mars or anything.
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Old 01-31-2020, 10:17 PM
mirwa mirwa is offline
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Quote:
Originally Posted by cliff_the_stiff View Post
Is my following statement correct?

Generally, starting with an appropriately adjusted truss rod for the current string tension; when adjusting a truss rod, either from the head or from the sound hole, we tighten the truss rod if we are increasing the string tension; and therefore also are loosening the truss rod when applying lighter string tension.
Not really, a difinitive answer cannot be obtained as every guitar is different even same brand guitars built to same specifications.

A block of wood 3 inches wide by 1 inch thick can hold string tension perfectly, however it is not possible to put our hands around said block to play a tune.

As we shape that block of wood for hand comfort we remove some of its strength, how much depends predominantly on species of wood and grain of the neck.

If we thin the neck down too far for comfort the wood may no longer be strong enough to combat string tension, in this scenario we add a truss rod for putting strength back into a neck

These days, most builders, main stream manufacturers simply fit a truss rod regardless of the above mentioned.

So....... if your neck is off a quality species of wood, with grain of the right direction and is thick enough to maintain tension, then changing the strings to a different gauge will make no difference to the relief

If.......your neck is of a cheaper wood or unfavourable grain direction or over thinned for comfort then a change in string gauge will require a truss rod adjustment

Steve
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Old 02-01-2020, 09:17 AM
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Quote:
Originally Posted by Howard Klepper View Post
Do not automatically change the truss rod adjustment when you change string gauge. Change it when the relief is not ideal. "Ideal" depends on strings and playing style. For the great majority of players it will be between about .003" and .007". The suggestion above of about 1/32" (.031") is way too much for anyone.
Thanks again for all of the help. My string changes went without incident. No adjustment needed.
Pretty Thomastik:
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