Gibson LP Jr vintage tailpiece position

[dfwadjuster]

I have a new LP Jr with the compensated tailpiece, if I wanted to change it to a non compensated tailpiece, where could I find a schematic on where the vintage studs should be drilled?

I've googled it, and I can find all kinds of info on the electronics, but nothing on the tailpiece positioning. I'm sure it's user error, but I decided to ask the forum...I figure several of you who repair, modify, or build them, would surely have the measurements.

 

[DoneOne]

where could I find a schematic on where the vintage studs should be drilled?

what the heck... time for some typing practice.

If I were drawing up plans, I wouldn't even consider putting X marks the spot for drilling the bushing holes for a vintage style wrap around... there are too many potential complications that would make those positions "off".

I think it's safe to say that most of the guys here would tell you it's better to position the bridge to the individual guitar.

i.e. this thread appeared yesterday:
http://www.mylespaul.com/forums/luthiers-corner/209308-fingerboard-scale-measurement.html

...but that's a TOM with a stop tail. For a vintage wrap around, it's the same solution, but with the added complication of not having the stop tail to hold the string tension while you're adjusting the bridge (that's shimmed up to the height you want).

so... use a cheap trapeze temporarily, or a wood block or aluminum angle with string holes drilled into it clamped to the body to hold the string tension while you adjust the bridge to string alignment and intonation. The string holes can be 2 & 3/16ths e to e with the bridge side of the block about an inch to an inch and a half from the butt end of the body (for a sc or dc jr). You can adjust and re-clamp to get it right.

Since you're doing a finished guitar - careful of the finish as you clamp - a block on the back also, etc. maybe paper or rubber or something between the blocks and finish.

Another complication is string spacing at the bridge. The bridge will end up being angled about 7 to 8 degrees which means the string through holes will be angled down - which means the strings will start their wrap over the top where the strings exit the through hole... so the center of the bridge will need to be above the center line of the body.

To get real picky (as I have a propensity to do), the thicker E string won't angle down as much as the thinner E because the edge of the string rubs up against the inside of the through hole... The thinner the string is, the more it can angle down in the through hole.

If nit picky perfect string alignment is important to you, you can get your initial positioning and then put the E strings through the bridge and stretch them lightly to recheck the alignment before drilling.

It's really not as complicated as it may sound; those are just a few things to keep in mind as you're doing it. Another thing would be that the bridge has adjustment screws - they adjust out, but can't adjust in past the posts. So err accordingly. If you use a thick set of strings to set the bridge intonation but may want to try a thinner set one day, then set the posts a hair more towards the neck.

lastly... absolute perfect intonation for each string may be impossible... it's a best fit thing. I've seen it posted that the low E is set slightly flat... that many prefer it that way.

if you do do it... let us know how it goes.

 

[LtDave32]

Here's how it was explained to me on how to set an LP jr (wraptail) bridge:


Measure from the nut face to the center of the 12th fret.

Transfer that precise measurement to the body, making a pencil line straight across, perpendicular to the neck.

Using a ruler,draw two lines straight back on each side of the neck where it joins the body, intersecting with the temporary bridge line you just drew.

Between these two lateral neck lines, measure above the bridge line on the treble side, 5/32". mark that spot.

On the bass side, measure below the bridge line 1/16".

Draw these two points. This is your bridge angle.

Now we establish the stud insert points:

With two pieces of string, strung through the E tuners on both sides and strung through the bridge, find your side-to-side bridge position, allowing the strings approximately 1/8" from each side of the fret board. Mark the outer positions of the bridge. Move the bridge to the bass side 1/16" to compensate for the strings laying over toward the treble side.

Measure with calipers the screw-in stud itself, the smooth part where the bridge will contact the stud.

Divide this thickness of the stud in half.

Take that measurement and mark it above your established line.

Drill on those points.

I took a great leap of faith using this method from a friend luthier who has been a Gibson authorized factory service center for years. I had really become fed-up with the "temporary trapeze tailpiece and shimmed bridge" method, figuring he would know the way the pros do it. He did. He asked me to trust him. and I did.

..He was right on the money. I did this on two LP jr builds. The bridges turned out as near-perfect as you can make a wrap-tail bridge position.