Welcome back to our guitar maintenance series. This is a part two of the blog on the action of a guitar – Setting the Action.

“Setting the action” is a termed used for altering the distance between the strings and the frets on a guitar. This adjustment can be done four different ways:

• Raising or lowering the bridge or saddle
• Changing the height of the nut
• Adjusting the dip in the neck
• Modifying the height of the frets

In this blog we will only discuss the first two methods above. Neck and fret modifications will be deferred to later blogs.

Adjusting the Height of the Bridge -Electric Guitars

For most electric guitars setting the action at the bridge is relatively easy. For bridges based on the Fender Stratocaster model string height can be changed by adjusting the height of the small Allen screws for each string.

 

A few important points to keep in mind:

· The adjustments should be small.

· After making an adjustment re-tune to concert A440hz pitch and check the action.

· If you are raising the action you should loosen the strings slightly before making adjustments as it will put more tension on the strings and neck.

· If you are lowering the action you should check for fret buzz at every fret after every adjustment. If you are getting fret buzz you should either raise the action a little or you could shave the buzzing frets down. We will cover fret shaving in a later blog.

 

Adjusting the Height of the Bridge -Acoustic Guitars

Most acoustic guitars do not have adjustable bridges, rather the bridge is glued firmly into place on the guitar. However, the saddle where the strings actually sit across the bridge can be removed quite easily as it is only held in place by string tension.

So firstly remove all the strings and you should be able to remove the saddle without too much effort. If you are lowering the action you can either file down the underside of the saddle or file down each of the grooves in the saddle. If you are raising the action you can pack shims (small slithers of wood or plastic) under the saddle or you can buy a new saddle.

Adjusting the Height of the Nut – Electric and Acoustic Guitars

Although you can change the action at the bridge, the guitar will not be set up correctly if the strings are too high or low at the nut. To lower the action at the nut you need to make the grooves in the nut a little deeper. Care must be taken when you do this. If you make the grooves too deep the strings will rattle on the frets (fret buzz) and you will have to purchase a new nut and start again. You can use needle files and small saw blades for deepening the grooves in the nut.

 

Some things to remember when lowering the action at the nut:

• You must ensure that the grooves maintain their initial semi-circular shape and size.
  • If you make the grooves too wide the string can slip out.
• The nut should have the same profile as the fingerboard.
  • If the shape of the fingerboard is curved across the frets the nut should have the same shape.
• The grooves should slope down slightly toward the head of the guitar
  • Because the scale length of the string begins at the front of the nut.

To raise the action at the nut it is best to purchase a new nut and carve out the grooves to the appropriate height. Although, you can make temporary adjustments by removing the nut and packing shims under the nut, you are better off to replace the nut.

To remove the nut from the guitar gently tap it sideways with a light hammer and a piece of wood to dampen the impact. Nuts are normally lightly glued into position. Take care with this in order not to damage the neck of the guitar. Oh and by the way take off the strings first.

- Axel