Building intonation into a home made guitar

[j48johnson]

How much should I angle the bridge to get the intonation accurate? I've searched the web on this but really found nothing. My Strat. has an adjustable bridge and the difference between low E and high E is 3/16". My Ibanez S470 is the same at 3/16". However, my Ibanez Artcore hollowbody is 9/32" difference between the two. Are hollow/semi hollow body guitar set up, (intonation), closer to an acoustic? (I don't own an acoustic or I would have measured it too) The difference between both of my solid body guitars and the hollow body is "only" 3/32". I am thinking of staggering the bridge 3/16" by drilling the holes for the bridge mount 3/16" from perpendicular compared to the centerline of the neck. Any help from people who have already built guitar(s) would be great!

[RJB]

I'm guessing the difference in hi-E to lo-E offset is due to the scale length of the guitars. Strat and such are 25.2" while I believe the Artcores are 24.75". I know that Gibson sets up the tuneamatics with an offset like this. This way the saddles for the 2 Es are basically in the center of the brigde piece.

I have to ask..... what style of bridge are we tlaking about here? Anything other than a 2 piece Gibson style or the old LPjr non-adjustable stopbar/bridge the bridge needs to be in alignment with the strings. Otherwise the string will be off center of the saddles or the strings will not run straight down the next.

[ChrisK]

Strats are 25.5".
PRS are 25"
Gib$on are (usually) 24.75"
NOTE: Based on an interview with Paul Reed Smith for Guitar Center in Nov 2007, he indicated that most Gibsons/LPs are/were actually about 24 9/16" and not 24 3/4".

[j48johnson]

I am building the guitar from the ground up.

I am going to use a hipshot baby grand bridge. I has two studs, one at each end on the outside of the respective E strings, that hold the second piece, the actual bridge to the guitar. On these studs there are adjustment nuts for the action and there is a set screw that threads into the bottom, (meaning the part of the bridge that is closest to the tail of the body where your string button is), of the bridge to set the intonation. Let's say you need to add length to the low E side of the bridge. You would turn the set screw in. If you need to shorten the string, you would turn it out.

Since the Baby Grand is a soild bridge, I'll never get the intonation perfect because of how it's set up. By lengthening the low E string side of the bridge with the set screw, you actually add length to all of the strings since the opposing stud is on the outside of the high E string. But the string that gets more length added to it by doing this would be the low E. The bridge would pivot on the other stud so the entire bridge would taper, low E being the longest string, to the high E being the shortest string.

I hope this clears up my VERY muddy explanation in my first post. If you have any more questions or comments on what I need to do, PLEASE post them. Like I said, I know I'll never hit it dead nuts for the intonation for each string, but I do need a good starting point so the first guitar I ever make won't sound like crap.

[UnklMickey]

j48johnson said:

...Since the Baby Grand is a soild bridge, I'll never get the intonation perfect because of how it's set up....

maybe i'm looking at different pictures or the wrong model, but i can't see the problem.

this looks like a cross between the "wraparound" bridge with setscrews to get the average offset correct and a "tune-o-matic" scheme where the exact compensation for each string can be adjusted.




so it seems to me the starting point would be to determine the amount of offset according to the scale length.

that should get you quite close to begin with.

after that, you will have LOTS of room for coarse adjustment with the setscrews, and a reasonable amount of final adjustment with the individual saddles.


unk

[Runewalker]

I've seen pix of these and they are curious. Like Unk said there are references to a one piece wrap-around, but only in the stud spacing. It is really just a Tuno with an integrated stop tail piece, with some stylistic elements in that "baby grand" fashion nod.

An issue I find problematic on built from scratch or. worse, bodies and necks where I convert from a 24.75" to a 25/5" scale is the travel distance of the Tuno saddles is much shorter than the Fender style strat bridges.

Notice that F-styles are installed parallel to the frets, while tunos are installed at an angle to the frets. The angle approximates a straight line intonation compensation required by the different diameter strings on a guitar.

You will see a similar angle in most acoustic bridge bars (not that I ever look at acoustics). So it is a little tricky on a new bod to get that angle correct for drilling holes for the post bushings. On a Gibby (24.75") It is approximately 1/8 to 3/16ths of an inch longer on the bass side than the treble string side. Unless the Hipshot's saddle travel is as generous as on a F-style bridge, this offset is critical.

I wish there was a heavy, solidly rendered Tuno with a long saddle travel. The 25.5s just take more travel than the 24.75s and there is less room for error on establishing the post placement when using a Tuno style on a 25.5" Not that it can't be done, but it is a quadruple measure job.

Unless you use very unusual strings, almost always the high E will be the shortest length string, and is typically the reference length for the nominal scale (24.75" or 25.5", unless you are going boutique).

below, with some image silliness, is a 24.75: bod upon which I put a Jackson style 25.5" neck. Unk named it Running with Scissors (a year + before Hollywood stole the name from him).

I include it because it is an example of the difficulties in rendering an "Unholy" marriage between Fender and Gibson style components. The intonation is not perfect because I cut the neck heel a little short, and there is not enough travel on the tuno saddles. They are pegged to the back of the tuno. It;s my teenage daughter's so she doesn't really hear the intonation issues, and they are slight, but annoying.

I am going to have to disassemble it and lengthen the heel a bit, then dowel the screw holes, and re-install the neck. Fixing it right the first time is a lot easier than re-dos.




RWS .... and Jimi likes it too!

[UnklMickey]

runewalker said:

... there are references to a one piece wrap-around, but only in the stud spacing...

....I wish there was a heavy, solidly rendered Tuno with a long saddle travel. ...

... Unk named it Running with Scissors (a year + before Hollywood stole the name from him).

hey Rune,

there is one other similarity, in addition to the stud spacing........the long set-screws that are at a right angle to the studs.

they allow for adjusting the over-all length and the 'offset'.

that makes the placement of the post MUCH less critical.

the studs just can't be too far toward the tail.



i really prefer a wraparound to a TunaMatic, but of course it's pre-intonated. it's horrendous if you use a string set with a wound G.

LeoQuan has an intonable wraparound that has MUCH more travel than a Tuno.



when i first heard of the release of the movie, i chuckled.

i KNEW you were laughing too, thinking about that guitar.


unk

[Runewalker]

UnK.... "there is one other similarity, in addition to the stud spacing........the long set-screws that are at a right angle to the studs.

they allow for adjusting the over-all length and the 'offset'.

that makes the placement of the post MUCH less critical.

the studs just can't be too far toward the tail.

There's something to ride in that last sentence.....

I was not sure if the hipshot had the adjusting screws, and yes that would accomodate more offset. However, I intuit that that approach risks compromising coupling integrity. I prefer that the stud shelf to bridge guide channels be fully engaged, opposed to push out by a small machine screw. Introducing a less secure coupling present the opportunity for minor ancillary vibration at the stud shelf, which in admitedly small increments, compromises securing the string to bridge interface.

That may just being obsessive.

RW

Hollywood shoulda given you royalities.

[RJB]

Well last night I did some measurements. At the E-E intonation points of my LP the offset is 13/64", and on the Tele it's 5/32". Some quick playing on CAD shows a mounting angle of 5.6° and 4.3° respectively. Measured offsets would be 5/16" and 1/4".

I'm thinking just Eyeball it. Put the 2 E strings on the bridge and into the tuners. Center the saddles in the travel area. Apply some gentle tension and with the strings running down the fret board where you like them. (centered, etc). Use the tuners to adjust the treble E to the desired scale length. And the bass E to the desired offset based on above or similar measurements. Now use the bridge itself to find the stud locations.

Just a thought. YMMV
Ron

[UnklMickey]

Ron,

your idea seems to make sense, but the strings will probably have a tendency to unwind at the tuners, making things a bit 'springy', so you could have a hard time keeping an even tension on the bridge. might work, but could get a bit clumsy.


Rune,

runewalker said:

...That may just being obsessive....

nothing wrong with that.

why should i be the only one allowed to have that kind of fun?

i think it probably would be best, it you could have the posts where they make full contact, and the setscrews aren't needed.

if your estimate, on where to put the posts is close enough, then you will have enough latitude with the individual saddles.

worst case, if you guess wrong, and you run out of room on any of the saddles, when moving it (them) toward the neck end, you could use a die grinder to deepen the 'U's in the bridge body.

worth avoiding, if at all possible, but definitely a way out, if you 'paint yourself in a corner'.

unk


PS. i'm glad you've started a movement to get Hollywood to give me the royalties.
i think you deserve a portion too, since it was your axe that inspired me to coin the phrase.
just send me half now, and you keep the other half when they send it to you.

[j48johnson]

Thanks a bunch everyone!

I think I'll kind of combine what I've read from you guys, set my high "E" at the length, add 3/16" inch to the low "E" with the saddles set in the middle of the bridge and the studs / posts all the way back into the bridge and not worry about the little set screws to move it around....unless after "quadrouple" measuring everything I really mess it up! Sound like a plan?

I think it may just work!

Thanks once again.

P.S. I made my body template with the neck pocket cutout yesterday and my neck fits like a glove!

Glued my flame maple top to the mahogany body today!

[UnklMickey]

j48johnson said:

...I think I'll kind of combine what I've read from you guys...

...Sound like a plan?...

like so many other things, everyone has brought at least one good idea to the table here, and the discussion has helped shape things.

sounds like a pretty good plan to me.

i'd like to add one more thought.

i'm liking ron's idea of using the strings, the more i think about it.

but it might be easier to use some electrical wire, maybe about 20gauge or so, instead of strings.

that should bend more readily around the tuners, so it won't be as 'springy'.

having the E and e 'strings', will help with the correct lateral placement of the bridge.

you can make sure that the gaps between the 'strings' and the edge of the fretboard at the body end are nearly equal.

it should be just a bit closer between the high E and it's edge of the fretboard for 2 reasons:

1 - the low E is a larger diameter.

2 - you will have a slight tendancy to push the strings across the fretboard toward the low E side as you fret.

at least that's my story....


"quadrouple" measuring

yeah, like the old saying goes: measure twice, cut once.


i don't know what's going on here. i've cut the dang thing 3 times and it's STILL too short!

[j48johnson]

I'm with you guys on setting the bridge using the strings from the nut / headstock to get the side to side placement.