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BurtonBacker
12-01-2018, 03:42 PM
Would like to know what the "nut" is to measurw from... is it the one at the top of the fret board (truss rod) or am i completely missing the translation... this is my first build i have an RCA 4 kit so any help would be appreciated.

Simon Barden
12-01-2018, 03:52 PM
Hi and welcome.

The nut is the piece of plastic (in this instance) at the headstock end of the neck with the notches in that the strings sit in.

24074

The flat side facing the fretboard is the face to measure from when checking scale length. The scale length is defined as twice the distance from the nut to the middle/crown of the 12th fret. So if this distance is 17", the scale length = 2 x 17" = 34".

Because of the way strings vibrate, there is a small 'dead' section at each end of the string that doesn't vibrate, and the thicker the string, the longer this section is. This is why the distance from the nut to the saddles with the guitar fully intonated, will always be a bit longer than the nominal scale length, and why the bottom E saddle will be further away from the nut than the G string saddle will be.

BurtonBacker
13-01-2018, 03:54 AM
Thank you very much... extreamly helpful :)

Tim Stahlmann
24-02-2019, 02:49 PM
Hi Simon. I am a first time builder as well doing a PB1 kit. When I measure from the middle of the nut to the middle of the 12th fret I get a measurement 433mm. A little longer than 431.8 that others have. When placing my bridge do I then measure 433mm from the 12th fret to the bridge saddle? Also is there a particular string saddle that works best as the low E and A strings have shorter intonation screws.

Cheers for you help.

Tim

Simon Barden
25-02-2019, 02:00 AM
Hi Tim. Most of your question has been answered in the other post you made.

The intonation length will always be a bit longer than the nominal (nut to 12th fret x 2) scale length as strings have a small length at each end that doesn't really vibrate. The thicker the string, the longer than length is, so the longer the overall string length needs to be to have a full vibrating scale length section. The G string on a 4-string bass will have the saddle furthest forwards because of this, but this will still be a couple of mm longer or so than the nominal scale length. The D saddle will be a bit further back, the A a bit further than that and the low e will have the saddle furthest back from the nut. This is why the E and A saddles have the shorter intonation screws.

You've got a long intonation screw length on ths D and G saddles, so you don't want the saddles too far towards the rear of the bridge when measuring, otherwise with the saddles right back, the intonation screws will be sticking in the air and catching the palm of your hand. Also, the springs can get really compressed and make it impossible to move the saddles back further.

So I normally recommend moving the G saddle forward so there's about 3mm of thread showing in front of the saddle, them measuring the scale length from the front of the nut by the G string slot. to the middle of the G saddle (with the bridge already centred correctly). That should give you a good bridge position. The saddle will almost certainly have to be moved back a bit once you've got all the strings on and you are checking intonation, but that will be an easy task.

Tim Stahlmann
06-03-2019, 02:52 PM
thank you Simon. Wonderful information. Beautifully explained. Cheers