Help Drilling for a New Bridge

SabbathFan0220

SabbathFan0220

New member
Hey guys, it's been a while. I need some advice before I drill for a new hardtail bridge on my Warmoth body. I have a body that was drilled for a Warmoth hardtail (which has three mounting holes under the string through holes) and I'm switching over to a bridge with four mounting holes at the corners.

How do I measure to line it up exactly? There's really no room for error in something like this. I have it lined up roughly by lining up the string through holes on the bridge to the string through holes on the body. Any opinions are welcome.

Thanks guys.

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Re: Help Drilling for a New Bridge

First, you need to mark the centre line of the guitar body.

With the all of string holes correctly aligned, the bridge assembly should sit perpendicular to the centre line. Its edges should run parallel to the centre line.

Judging by the photograph, your new bridge will have more than enough range of adjustment to intonate the guitar correctly.
 
Re: Help Drilling for a New Bridge

The way I'd do it is measure nut to 12th fret. Then replicate this value from the 12th fret to the bottom of the body. This should correspond to the mid-range of the travel on the saddles.
This way you have the correct scale length and exactly the same amount to intonate each way.

But I may be completely wrong!
 
Re: Help Drilling for a New Bridge

+1 to Funkfingers and Pierre.

Put down contact paper on the body so you're not marking up the finish.
Find the centerline with the old bridge and neck installed.
Using the old bridge, intonate the guitar correctly.
Measure from the inside edge of the nut to where the string breaks over the saddle for the closest and furthest strings. This should be the guitars scale length (24.75", 25", 25.5") +/_ 1/4" at the most.

Now take off the old bridge and center the new bridge to the centerline.
Adjust the saddles so that the they are all about halfway along their travel.
Move the new bridge until the saddles are at the scale length.
Compare to your original bridge saddle closest/furthest measurements to ensure that you are within that range on the new bridge.
Adjust until you are.

Mark the screw holes.
Remove contact paper.
Drill pilot holes.
Screw down bridge.
Restring.
Tune.
Intonate.

???

Profit.
 
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Re: Help Drilling for a New Bridge

Since the string holes are already drilled, you could line them up with 2 dowels that fit through the bridge string holes nice and snug and insert them to the body holes. Line it straight (because there may be some play), then mark the spots where the new bridge screws would be through the bridge mounting screw holes. You could get away with just 2 dowels, one on each of the E string holes.
 
Re: Help Drilling for a New Bridge

Just in case you didn't already know; you should use a drill press to make sure the holes are straight. It will also help you line them up more precisely. If a drill press is not available to you then they make small attachments for handheld drills. If you have to freehand it then take extra care to keep every thing straight. Maybe even rest a combination square on the body to visually keep the drill at 90 degrees. Either way, use an awl (or something similar like a small nail) to mark the starting location of the holes by putting a small dent into the wood. This will help to make sure the drill bit starts in the right location and does not wander.
 
Re: Help Drilling for a New Bridge

Thanks for all the suggestions. Like ErikH said, the string through holes are already drilled, so it's just a matter of lining up the holes on the body with the holes on the bridge. I don't need to calculate for scale length because that's already been done for the old bridge.

I tried a version of his dowel idea using nails that were about the right diameter. I put the nails through both E holes, pushed the bridge forward and marked the mounting holes, pushed the bridge back and marked again. I ended up with two marks for each mounting hole. They line up exactly with my eyeballed marks from before. I think I'm ready to drill (don't worry Jolly, I'll use my drill press).

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Re: Help Drilling for a New Bridge

Looks good. You don't have to go very far down. The way I make sure of that is by putting a piece of tape around the bit at the exact depth I want and then I can see it and know where to stop. Makes it a lot easier than guessing.
 
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