EX-4: Bridge Position / Scale length problem

[MoSch]

Hi everybody,

I bought an EX-4 Kit with some custom modifications a looooooong time ago and spent a lot time with planning, deciding upon components and basically doing everything to prevent me from actually working on it.... but i started recently
Until now only reading this forum already helped ma a lot! Thanks!

But now - after shaping my headstock - it is time for the "Mock build” according to the manual.
And here I am with my first situation I could not solve by searching the forum:

The holes for the bridge seem to be closer to the neck than I expected. When checking the scale lengt I can only reach the stated scale Length of 846 mm if I put the bridge into the longest possible position...
I am not experienced with advanced woodwork, so I hope I can avoid filling and re-drilling the holes for the bridge... eventhough they seem to be slightly tilted as well (not the way as explained in the manual but the low strings being slightly closer to the neck.
I guess this might be due to my customizations (the cavities for pickups are changed to P-style pickups and the control-cavity is slightly tilted).
The measure between inner nut and middle of 12th fret is 431 mm roughly as expected.

Are there any tricks to solve this issue?
Can I simply pull out the neck a few millimeters from the neck pocket without losing stability?
How manny additional mm will I need in scale length especially if I intend to use a low B string?

Thank you for your help :-)

[fender3x]

Judging by the pics, it may not be as bad as you thought, but the bridge does look a little close to the neck. I am not sure where a low B string would be, but my low E intonated at about 871mm on a four string bass with the G at 862. If the bridge were placed properly the G string saddle should be at 862 with the lock-bolt in the first or second hole. The G saddle does not need to be all the way forward, but you want a good amount of adjustment.

You can adjust the neck placement. You would need to move it quite a bit "north." Maybe 12mm or more. Is this a glue in neck or a bolt on? Do you have any overhang on the fretboard? If the fretboard will hide the gap It should be doable. You may want to fill the gap with strips of wood veneer if it's a glue in neck. If it's a bolt on that would not be as important for stability.

[Rabbit]

fender3x: The Explorer basses are bolt on neck. Incorrect bridge hole placement seems to a common theme on most of the Exp builds I've seen here. On mine they were too close together. The other common complaint is the bridge is too high.

[fender3x]

fender3x: The Explorer basses are bolt on neck. Incorrect bridge hole placement seems to a common theme on most of the Exp builds I've seen here. On mine they were too close together. The other common complaint is the bridge is too high.

Thanks, Rabbit. That is "Glück im Unglück" (roughly, "luck when you are unlucky") A bolt on neck allows you to solve a multitude of problems. If the Holes are in the wrong place, you can simply re-drill to put them in the right place. fill the old holes with a dowel. You'll see were at least two of the holes were, but only on the back. With the neck in the proper place if the fingerboard covers any visible gap, you may not need to do anything else. If it does show, you may want to put a piece in so you don't see the gap. You'll be able to see it, but it may just look like part of the neck assembly.

I wonder if MoSch has the same bridge as yours, Rabbit? After seeing you post, I looked at a pic of the kit and the bridge there looks different...more like a fender bridge. It also does not look like the miserable three point bridge that came with my ESB-4 kit or with the T-bird kits...which is good. MoSch did you use a different bridge than the kit?

In any case, if the bridge is too high, you should be able to correct with a shim. I make mine with pieces of veneer, but you can also buy them or make them out of other stuff.

[MoSch]

Hello fender3x,
thank you very much for your help!

As Rabbit already said, it is indeed a bolt on neck. Thank you for the quick comments as well.

The fretboard has 6 mm overhang.

There are picures attached with two different "spacers", one 9 mm one 16 mm to check how it would look like




The neck pocket would allow something as 12 mm displacement without the need of changing any holes.



Indeed, the bridge is not the one delivered with the kit but a Babicz one which was supposed/suggested as a replacement with easier adjustment options. It was also supposed to make slightly lower action possible - which is not obvious by only looking at it for me.
I crosschecked with the one delivered and indeed this would give a few more mm for adjustment of the scale, but I guess not enough for the low B.
See image with both bridges. I read not so nice reviews on the original one...



Also thanks a lot for the idea with the shim (below the neck I guess?). I think I read about it in another thread already. So I have to worry less about bridge height and can concentrate on scale length.

So basically I now have to decide if I want to reposition the Bridge holes and fill the old ones or fill the gap with the neck in order to use bridge and tuning as I intended to...

Is one or the other preferably? Maybe I can gain some courage from the acceptable result with my headstock and think about the bridge-repositioning... I guess that would be the more "professional" way to go?

I hope to be able to give this project an intense color so maybe I can hide whatever to fill a little...

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Thank you for the measures for comparison... I could have thought about this myself... so in case someone will meet a similar question in the future and reads this thread, I add a table below with the basses I could check. It is absolutely consistent with your suggestion "Maybe 12mm or more".

Instrument	Nut - 12th fret	B	E	D	G	delta max
Dean ML	431		866		863	4
Fender Kingman	385		778		767	8
Aria Pro II ZZB Deluxe	410		829		821	9
Charvel Star	431,5	876		866,5		13
Hohner B2A	432		870		866	6
Dean ML Tour	431,5		870		869	7
Cort C5	431	872	869	865	862	10

[fender3x]

You have been doing your homework! One thing that I think you can do with your chart is to throw out the measurements on the necks that are less than 431 from the nut to the 12th fret. Those are short scale basses. Yours is standard (34") scale. That is pretty good verification that the 34" scale basses tend to intonate at 362mm or just slightly more. If it were me, I would want the low B to be able to travel to at least where the Charvel is.

Would it be better to move the neck or the bridge? Either way something is going to show with a clear finish. With a solid color finish you can make it so neither shows. With a dark finish not much will show, either way. With similar kinds of issues, I can say that I have finished with a solid color, which is the easy way out ;-)

The 9mm spacer is not enough for the Charvel or the Cort. Neither is 12mm if you want to be able to intonate like the Charvel. It might be enough for a low D but not a low B. You might be able get the neck out to 16mm without problems. If you drill the neck carefully and tighten carefully you only need a few mm clearance for the screws.

That said, if it were me, I would probably move the bridge. You want to string the bass with very low strings. So, if you had a G string you'd want it to intonate at 862. For a low B you'd want it to go back 1.5 cm or an mm or two more. The Babicz has tons of travel so why not have it?

The only disadvantage to moving the bridge is that you need some way of stabilizing your drill so that you make the hole exactly perpendicular to the body. Also you lose access to, maybe, one fret.

There are a couple of potential advantages to moving the bridge. You can position the bridge to get the maximum travel that you might want from the saddles. Since the neck won't extend as far, you may have slightly less neck dive.

One possibility that also occurs to me is that you might not have holes to fill if you move the bridge. You did the right thing by getting rid of the kit's 3-point bridge. It's junk. But it came with some ferrules and mounting screws. Once you move the Babicz, you might be able to put in these ferrules and posts..or other large screws. I think they would look like they were part of the bridge, and no one but you would know that they are not ;-) If anyone notices you can tell them that it is drilled for a 34" neck and a 32.25" neck (like the Aria's). Maybe one day you will want to convert it to short scale... ;-)

[Rabbit]

TI wonder if MoSch has the same bridge as yours, Rabbit? After seeing you post, I looked at a pic of the kit and the bridge there looks different...more like a fender bridge. It also does not look like the miserable three point bridge that came with my ESB-4 kit or with the T-bird kits...which is good. MoSch did you use a different bridge than the kit?

In any case, if the bridge is too high, you should be able to correct with a shim. I make mine with pieces of veneer, but you can also buy them or make them out of other stuff.

Yes he does. The high action the standard bridge gives isn't an issue with the Babicz, the level of adjustment is awesome. It's well connected to the body where as the standard kinda floats.

My bridge hole mis allignmnet I was able to correct with a file, but it looks like MoSch may have to go with the dowl and re-drill approach. Just be aware that the dowl requires several applications of sealer to make less obvious due to the end grain. If staining the end grain also tends to stain darker. You could go with a contrasting colured timber for the dowel and make it a feature.

[Trevor Davies]

+ 1 for the dowel and redrill to move the bridge back. For moving the neck, I would worry about the heel of the neck splitting when screwed onto the body (due to the small distance to the screw holes).

MoSch - How are you intending to finish the body?

[fender3x]

I would worry about the heel of the neck splitting when screwed onto the body (due to the small distance to the screw holes).

+ 1... I just looked at my p-bass and the mounting screws closest to the heel of the neck are almost 3 cm from the heel. I was initially thinking it might work...but I wouldn't risk it either.

[MoSch]

Thanks again for all your thoughts, ideas and comments!

I think I have to make myself comfortable with the idea of the fill-and-drill approach.

With a solid color finish you can make it so neither shows. With a dark finish not much will show, either way. With similar kinds of issues, I can say that I have finished with a solid color, which is the easy way out ;-)

MoSch - How are you intending to finish the body?

I hope to color the bass in a solid pink and black zebra pattern so it should be possible to hide the dowels

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The only disadvantage to moving the bridge is that you need some way of stabilizing your drill so that you make the hole exactly perpendicular to the body. Also you lose access to, maybe, one fret.
There are a couple of potential advantages to moving the bridge. You can position the bridge to get the maximum travel that you might want from the saddles. Since the neck won't extend as far, you may have slightly less neck dive.

Alright, I will do some research on dowels and if I can get acces to a drill press somehow for three holes.
Also I have to check carefully the suitable drillsize for the ferrules.
And how to get the ground potential to the bridge

I am not bothered by losing a fret... I am not using high notes a lot
And for neck dive... well if that was my main concern, I should not have designed the headstock as a trident

---

One possibility that also occurs to me is that you might not have holes to fill if you move the bridge. You did the right thing by getting rid of the kit's 3-point bridge. It's junk. But it came with some ferrules and mounting screws. Once you move the Babicz, you might be able to put in these ferrules and posts..or other large screws. I think they would look like they were part of the bridge, and no one but you would know that they are not ;-) If anyone notices you can tell them that it is drilled for a 34" neck and a 32.25" neck (like the Aria's). Maybe one day you will want to convert it to short scale... ;-)

That is a very nice idea indeed. I also was thinking in similar way if I can use the holes as a feature, maybe screwing in LEDs or other stuff.
However I needed to get further ferrules as the Babicz did not come with its own.
And way more important: As the original holes seem to be not perfekly aligned along the bass-axis I think I prefer to solve this issue when redrilling but then the old holes wont be symmetric...