Scale length doesnt mesh

[lawry]

Hi guys,
Just started building my RC-1 and am at the stage of applying wudtone. But before then I thought I would check out how far I had to insert the heel of the neck into the body. That's when I became a bit uncertain. I installed the pickup and bridge so that I could mark the neck for gluing after measuring the scale but when the neck is snug up to the pickup the distance from the nut to the 12th fret is 314mm and the distance from the 12th fret to the bridge (not the saddle) is 318mm. So how do I get the 12th fret to sit in the middle of the scale length? I'm open to any advice here.
Thanks,
Lawry

[WeirdBits]

Can you post the measurements from the crown (middle/peak of the fret wire) of the 12th fret (treble side) to the centre of the treble bridge post, and repeat on the bass side to the bass post (make sure the neck is square to the body so the measurements aren't skewed). Also, can you double check the measurement from the fretboard edge of the nut to the crown of the 12th fret (your pic is a little dark but it looks closer to 313mm on my iPad).

With 314mm from the nut to the 12th fret, you should have ~315.5-316mm from the 12th to the centre of the treble post and ~319mm to the bass post (make sure there is no lean on the bridge posts, or just measure to the centre of the holes). That's the typical compensation range for a tune-o-matic bridge. If you have a long enough ruler, it's best to do full scale measurements from the nut to the bridge posts/holes, rather than from the 12th..

[Gavin1393]

/<\\/p>[]<\\/p>/Installing the Bolt-on neck

We acknowledge the contribution of one of our past Forum members in this post.

Perhaps the most important part of building your Pit Bull guitar kit is getting the neck centred and correctly aligned. It can seem to be a daunting task; with the right knowledge, some patience, and a bit of string, it is a snap.
As with all aspects of building a guitar, attention to detail is essential. The more attention to detail, the better the guitar will be.
Many people don’t realise that the neck has to be right in three dimensions- back and forward to get the right scale length, side to side to get the right alignment, and up and down to get the inclination to give the right action, and bridge and pickup relationships.

:P The steps:
TIP: You don’t need to use a tape measure to measure- a piece of fishing line or wool or string is all you need (except maybe for Step 1, but that’s up to you). You are comparing one measurement against another.
We’ll discuss the steps to getting your neck pointed- literally- in the right direction. I would suggest that you do this, or at least do a dry run, before any painting on the body or neck. That way that way, if you put a scrape on the guitar it can be fixed when finishing. Scraping an already finished guitar- well, not a good thought, is it.
Setting the Scale Length
Don’t assume that by jamming the neck as far as it goes into the body the scale length will be correct.
Measure the distance from the edge of the nut to the high point (the crown) of the 12th fret. Wind all the saddles as far forward (towards the pickups) as they will go. The distance from the edge of the pickup side of the saddles (on the bridge) to the crown of the 12th fret should be the same distance. Most times though, you may find that the second measurement from the saddles to the crown of the 12th fret is approximately 3mm longer. This s called compensation and is quite normal.

/<\\/p>[]<\\/p>/String Compensation
If measuring the full scale length (i.e. the full length – not just to the 12th fret as mentioned in the shortcut-tip above) we usually measure at the top-E string. That’s because this string is the thinnest and requires the least amount of string compensation. This string is, therefore, closer to the actual scale length of the instrument. The other strings are generally compensated which means they’re actually slightly longer than the scale length.

/<\\/p>[]<\\/p>/What is compensation?

When you fret a string somewhere along the fretboard, you actually sharpen that string’s pitch by a tiny amount. To compensate for this, each string is made a little bit longer than the instrument’s actual scale length, thereby ‘flattening’ its pitch. The amount that each string is made longer (flattened) depends on that strings size – thin strings not much and getting progressively more as the strings get thicker. Clever, eh?

To nicely illustrate it, this is why acoustic saddles are angled – the sounding length of the thicker, wound strings is actually longer than that of the thinner strings.

Many guitars have adjustable bridges and/or string saddles to allow each string’s compensation be accurately set. Setting the compensation is referred to as ‘intonating‘ the instrument and the compensation overall can be called ‘intonation‘. .

How you work out the measuring point on the saddles will be different, depending on what sort of bridge you are using. You may have to move the bridge or neck slightly to get it right. Be wary of any gaps in the neck/body join, though. You need a tight fit for a good transfer.

/<\\/p>[]<\\/p>/Square the Neck
The first step to having a square neck is to identify some points of reference on the neck and body of the guitar. You are looking for a couple of points that are square to the centreline of the body, and equally on either side of the centreline. It might be the nust slot on the neck; it might be a pickup rout on the body; it might be the string through-body holes on a Tele, or pivot screws on a Strat or Floyd. They must be square- for example, the bridge on a LP style body won’t be any good because it’s at an angle.
This is crucial. Again, attention to detail is paramount!
Here’s one I prepared earlier… Ignore that this guitar is finished.


There are four points we will refer to. Let's call them A and B on either side of the nut, and Y and Z on either side of the pickup rout in this case- maybe a corner of the rout. It has to be a small point because you are trying to be precise, as you will see. I stick in pins at the points I want to use to measure.

The first measurement we take is A to Y, and B to Z. If they are the same, the neck is at the correct angle compared to the body. If they are not, then the neck is pointed towards the measured shorter side.

The next measurements taken are A to Z and B to Y. If these are the same, then the neck is on the body centreline. If they are not, then the neck is straight out from the body, but not on centre. The neck needs to be moved- if A to Z is shorter, the neck needs to be moved to the A-Y side. The other reason that these measurements might be out is that the neck is twisted, but that is not going to happen with a Pit Bull kit.

/<\\/p>[]<\\/p>/Setting the Neck Angle (or Inclination)
There is nothing worse than playing a guitar with the wrong inclination- the angle that the neck meets the body, when that angle suits the bridge that is being used. In this case, close enough is good enough because you have a few adjustments that can be made after the guitar is finished. These adjustments include the truss rod, the bridge and the nut.

So, how to do it? It is as simple as the other steps. Set the neck in the body, install the bridge with the saddles about half height, and the pickups (or pickguard if the pickups are mounted in it).
Run your now favourite piece of string from both e-string slots on the nut to the saddles on the bridge. Check out the gaps between string and fretboard at the 12th fret and at the last fret. There should be a reasonable gap. Remember though that the string tension and truss rod will affect the finished neck. Remember, this is one of the rare cases a case where near enough is good enough.

If the inclination is too shallow, the action will be too high; if it is too steep, the strings will be rubbing across the frets. In both cases, it is worthwhile taking time to get a reasonably good angle set up now, to reduce the adjustment required later.

IMPORTANT!!! This goes for most things in life- do not use up all your adjustment during the initial setup! To do so means you have a really, REALLY bad setup.
EVEN MORE IMPORTANT!!! Don’t go hacking at your new guitar to get everything right. If the neck angle seems wrong, it probably isn’t. Stop, have your favourite non-alcoholic beverage, watch the football, and come back later.

If it turns out that the neck is not sitting right, DO NOT GO HACKING AT THE GUITAR! A small amount of hack will have a huge change at the business end of the guitar. If you are convinced that there needs to be a physical change, use a shim to make the change. To make the shim, I recommend a sheet of paper and some spray-on epoxy. Spray the paper until it is wet through, LET IT DRY COMPLETELY so it doesn’t stick to the neck and is as hard as it can be so you don’t squash it. Squashing it sort of defeats the point of it.

Cut a piece or two as wide as the neck pocket and 12-20mm long. If the neck is too shallow, put it at the body end of the neck pocket. If it is too steep, put it at the nut end. If that is not enough to fix it, then you have bad or mismatched components. Of course, one of the advantages to a Pitbull guitar is that it is made to fit together well!

In summary, every time you move the neck, you need to redo all three measurements. You’ll find, however, that you’ll quickly pick up the groove, and it will only take three or four processes to get the neck right. And lastly, don’t be afraid to pencil the neck to give some guidance to get it back into the same spot after the body is finished.

Video: Attaching a Bolt-on neck
[embed]http://www.youtube.com/watch?v=-azQ5FMzeXA[/embed]
Video: Glueing a set-neck
[embed]http://www.youtube.com/watch?v=eCj2AaLIa-E[/embed]

[lawry]

Hi Scott,
Thanks for the reply, especially on a Sunday. Firstly, I have measured to distance from the nut to the crown of the 12th fret and it is closer to 313mm than 314mm. The distance from the crown of the 12th fret to the Bass post hole-centre is 323mm and to the Treble post hoel-centre is 320mm NOTE: this is with the pickup in place and the neck butting against the surround. If I remove the pickup I can move the neck closer so that the distance to the Bass post is 320mm and to the Treble post is 317mm. These measurements are as good as I can tell without installing the posts. The attached pic shows the gap available after butting the neck up to the pickup and then removing the pickup. Hope this all makes sense.
Cheers and thanks,
Lawry

[lawry]

Just re-read my post after sending it. Man, a couple of embarrassing spelling errors there!

[dingobass]

Hey Lawry,
Those measurements with the pup in place are pretty well spot on for normal compensation.

[lawry]

Hi DB. That's fantastic. Now that my angst has been placated I can move on to the next stage.
Many thanks to all for the advice. As this is my first ever build I am a bit nervous and uncertain so really appreciate your input!
Cheers,
Lawry

[stan]

sounds like you are being pretty careful Lawry, it's sure to look good in the end