I have to install a bridge (drill mounting holes) on a blank Strat body. How do you find the correct position for the bridge? Do I need a Strat schematic for dimensions?

I would temporarily install the neck before commencing this operation. Pencil in a datum line that bisects the fretboard from the nut all the way to the lower edge of the body (where presumably the lower strap button will reside). Ensure that this line is also centered on the body, using the body's "waist" and "hips" to calculate the precise midway point. The bridge will need to be centered along that mark. Next, measure the half-scale dimension from the nut to the twelfth fret. This same distance from the twelfth fret to the body is where the bridge's saddles should be located for proper intonation. Mark that location then place the assembled bridge on the body, with the saddle intonation screws adjusted for mid-point travel. Once you have it aligned with your penciled datum points, mark the locations for the bridge-plate screws. I recommend using a drill press for the final step of this process.

HTH

Arjay

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"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY

Good post.

To add to it, a nice way of finding the centre line from which all your measurements proceed is to install the neck (as mentioned) and then run a long steel rule down one side of the fingerboard, flat to the body and extending up to and beyond the trem cavity. Draw a pencil line along that straight edge. Then do the same thing running the rule down the other side of the neck. Now you can measure halfway between these two lines to find the line that runs down the middle of the fingerboard and on across the body. That's your datum (as Arjay says).

You need the bridge centred on the line of the neck, not on the middle of the body (which may not be the same place), because the bridge and the neck work together and you want the run of the strings to be correctly aligned within the edges of the fingerboard.

Next, you have to position the bridge so that it is exactly the right distance from the front edge of the nut - which is the other datum around which all guitars are built. The distance from the front edge (fret side) of the nut and the breaking point on the top e string saddle is the scale length of the guitar - 25.5 inches on a Strat.

That will help you position the bridge in exactly the right place for the guitar to intonate properly... but there's more to it than that. You still don't know exactly where the centres of the screw holes you need to drill have to go, so that they will be in the right place to meet the knife edges on the trem base plate. How to do that?

Here's how it works with a two-point trem - the principle is exactly the same with a six-screw bridge. You need to know the distance from the breaking point on the top e saddle to the middle of the treble mounting post/screw. So take a scrap piece of wood and drill some mounting screw holes in it, like this:



Now you can accurately measure the distance from the string's breaking point on the top e saddle to the middle of the mounting post or screw:



Now you take that distance (probably something in the region of a quarter of an inch), subtract it from the scale length (25.5 inches) and that gives you the distance of the centre of the mounting screw holes from the front of the nut. Somewhere around 25 1/4" - but you have to measure your own bridge to get it exact. Now you can mark that position onto the body of the guitar:



Once you've marked it all up it will look something like this:





Drill the holes and, presto, you're done:



There is nothing worse than bridge mounting screws that are not at a perfect 90 degrees to the body. So, as Arjay says, a drill press is highly recommended for this - assuming you have one big enough to reach across to the middle of a Strat body. But lots aren't big enough, especially of the home-workshop variety. So something like this is the next best thing (set to 90 degrees, obviously):



Or this:



Hand-holding a drill for this job is taking a big risk - and there's no second chances if you get it wrong with bridge mounting positions.

Last thing, if you need a few more pictures this page of an old thread of mine might help (halfway down):

viewtopic.php?t=30747&postdays=0&postorder=asc&start=495

Good luck - C

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Jeez...Were you guys trying to scare him away....

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"C'est parti mon Kiki "

That's great help. Thanks very much. I was going to get that same drill press for this job. I'd much rather have a luthier do it but he wants too much.

Is there also some kind of laser pointer you can use to align the neck and bridge?

1. Also, how should the line of the top of the frets (at neck pocket, 18th-22th) measure up relative to the average height of the saddles (to insure that the neck does not need shimming, etc.)? I need to check this because this body is a private make and taken from '62 Strat dimensions.

Plan your steps, work slow and deliberately, and follow Ceri's excellent illustrations -- you shouldn't have any difficulties.

Best of luck

Arjay

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"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY

Hi again cool9.

Hm. Let's try it again. A laser pointer is no use to you, but it's easy with just as steel rule. Watch.

Imagine this is an undrilled body:



We run the long rule along one side of the neck, like this:



We mark where that line is as it arrives at the bridge cavity:



Then we do exactly the same thing on the other side:



Which gives us two lines in front of the bridge cavity:



From those we can measure off the centre line, mark it, and then position the bridge:



Next we need to find how far to position it from the neck. We measure the scale length (25.5 inches) from the front of the nut to the string breaking point on the top e saddle:



If you have a six-screw bridge you can cheat a bit at this point and simply mark through the screw holes with a pencil by eye. It won't be perfect, but probably good enough:



Drill your holes, beautifully straight and true, and - bingo! - you're done:



I can't make it any simpler than that.

If you have a two-point bridge rather than a six-screw one you are just going to have to take a deep breath and struggle with my instructions in my previous post, because you need to get them absolutely perfectly positioned, and that's the way to do it.



cool9, all Fender Strat neck pockets are 5/8" / 15.87mm deep, regardless of year or model. So long as the one on your body is that depth then your neck will orient correctly with the bridge. If it isn't the right depth... well, measure it and we'll cross that bridge if we have to.



Cheers - C

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Hi Cool9!

Ceri's superb instructions for both 2 point and 6 screw bridge installation is by far the best in terms of writen and visual content. Much better than anything I've found on both the web and in the guitar building books I own....



...And I own a few...

In most cases, Google is your friend, but for bridge installation, Ceri is. Trust me, there's no better instructions out there.

Enjoy!

Andy

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Pending Greatness

Well done Ceri...that is a keeper for sure...nicely done indeed!

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"Where would rock and roll be without feedback?"

+1!!!

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You dig?

+2 If Ceri were to write a 'how to' brochure with illustrations,
it would be a huge seller me thinks!

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Being able to play and enjoy music is a gift that's often taken for granted.

Don't leave home without it!

Even I'd buy it!

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You dig?

I like the 60 grit wet/dry scuffer earning a well deserved rest....

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"C'est parti mon Kiki "

Me too!

Also wouldn't mind picking up a copy of "Martian's Galactic Guide to Guitars".

Andy

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Pending Greatness

Aw, you guys...



Like the Guitar Player Repair Guide, but six times bigger and ten times more useful. Put me down for three copies.

Cheers - C

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