Starting an ESB-4 kit

Just got my kit today. Thank you.
I've read the horror stories from fender3x and Roger79. The bridge bushing holes miss the body center block. The threaded studs suggested by Simon Barden, in this case, don't look doable. I've decided to cut to the chase and use the thru-the-body string mounting. How far back from the bridge should the string ferrules be located? They look like 5/8" on the bass built by Roger79. Too close and the sharp bends in the strings looks fragile. Too far away and I might run into string length trouble.

Not my first build. Bought a 335 from another dealer by mistake but I don't play guitar. Decided to build it build it anyway. Nice kit. It was a breeze and a guitar playing friend is agog over it.

Hi Jason and welcome.

I suppose one way to do it is the empirical way, and get hold of some of the long strings and see what you have to play with.

The string break angle can be quite severe and still be OK. If you think about rear mounted strings coming out of the bridge plate on say a P-bass bridge, they probably are bent through 50°-60° without coming to any harm. That's far more that the worst break angle over the saddles!

What you really want to avoid are the strings touching the rear of the bridge itself. So that determines the maximum break angle.

So you first need to decide whether to use the kit bridge or a bass T-O-M style or whatever, as the rear of the bridge will be slightly different in each case. Then you'll need to calculate the bridge height, and from that and the break angle, where the strings will hit the body. You'll need both the rear ferrules, and smaller ones for the top (or a drilled plate) to stop the strings wearing the wood away.

One other bridge mounting alternative not yet mentioned, is to drill through the body with an 8mm drill in the centre of the bridge post holes, and fit M8 bolts from the rear that screw into the post bushings from the rear of the bass and that will certainly hold them in place. You'll just have to cut the bolts to length so that they screw in enough to hold the bushings in place whilst still allowing the posts to screw in from the top (these could also be slightly reduced in length if necessary). The bolt heads could be slightly recessed if necessary (if pan head), or you could use countersunk heads so that they lie flat at body level.

Just another idea to ponder.

Please ask any questions you want, and feel free to put your plans forwards before implementing them in case we can see any pitfalls.

All the best with the build!

Ooooh. I will think about this one. The threads are only 1/2" long. I could turn my own bushings with full length threads. with the thru-bolts they wouldn't need to be knurled.

hmmmm............

I feel you'd probably still want something to stop the insert turning when you a) insert the screws from the rear and b) insert the posts from the top.

You can get longer post inserts, though they are not always easy to find. I did buy some a couple of years ago, but I'm struggling now.

It;'s a shame that the posts use 12mm holes, as you can get expanding/locking base inserts for 10mm holes, for use with Floyd Rose trems and other 2-post trem systems. e.g. https://www.fredguitar.com/en/access...g-function.htm. If you can get hold of something like that, then you could always plug and re-drill.

I could put screw driver slots in the top. With the stock bushings I'm guessing I will have about 6mm thread engagement on both sides of the guitar. Seems like enough for 8mm screws but I would feel better with a full diameter of engagenent. I don't know the thread pitch.

I had thought of using a floating bridge but those I have seen are too tall or too short. And then I think of fender3x's ordeal with the tail piece.

Thanks for your ideas. Now I am off the to hardware store for some screws (I hope).

I may be over thinking this. What is wrong with drilling a few holes through the bridge plate and screw it down?

Anybody have a picture of how these tuning machines are mounted? I see there are left/right pieces but which goes on which side and the orientation of the mounting plates?

You could just epoxy the inserts in place. Probably preferable to screws. Just don't forget to fit the bridge grounding wire first!

The tuning peg is mounted so that it's on the side of the tuner away from the body. Slightly less important on a bass tuner than a guitar one (as the post is wider and has more support), but it's arranged that way so the string tension pulls the top of the post, and as a result, the bottom of the post with the gear on it is pushed against the tuning peg gearing which keeps things tight and minimises backlash in the gears.

A bit of a tight fit on that headstock as the tuner bases are wide, bigger than the originals I think.

It should look something like this '66 EB-2 headstock.

Attachment 43285

What luck. That's the way I put them on.

I'm leaning more and more back the thru-the-body ferrules. The screws from behind might not have enough of the center block to bear against without crushing the body. The entire interior on the control side is a mess of splinters. Looks like a perpetual buzz. Looks like a whole lot of problems would go away if that block was wider at that end.Attachment 43286

Well, I finished the beast. No buzzing from the splinters but several frets need some work. I ended up epoxying the two rear bridge bushings (one of them had no support underneath the guitar top) and no string through ferrules. So far so good.
I'm puzzled how the bridge should look once it is where I want it. Should it be parallel the the fret board? Sloping up/sloping down? Does it matter as long as it sounds good?

I'd suggest parallel, mainly so that the edges of the post slots are square against the posts. But there probably isn't anything against the rear being lower than the front slightly, which will put a bit more downward force on the saddles in the slots. But not so much that the strings touch the front of the bridge.

Having the front a bit lower than the rear would reduce the downward pressure on the saddles. As the kit saddles don't have the best fit, anything that helps keep them from moving helps.

The original Gibson 3-point bridge was a replacement for the previous 2-point bridge which had a tendency to tip forwards. So definitely flat or just very slightly backwards.

https://www.flyguitars.com/gibson/ba...ointbridge.php

The adding some extra springs idea mentioned on that web page might be of benefit and could put enough tension on the saddles to stop them falling out when you take a string off.

Thanks. I thought about the spring idea myself. And strings with those stupid caterpillar windings give me grief elsewhere.
Now that I have this beast (Nyx is her name) built to my satisfaction I want to screw it up. Has anybody converted this to a bowed instrument? No doubt the bridge is the wrong shape and possibly the curvature of the neck is all wrong but I like the unique. And fretless possibly would sound more mellow.

The 12" radius neck and bridge will certainly make bowing individual strings hard. A cello typically has a neck radius of around 2 3/4" and a double bass of around 3 1/2". There's no way you'd be able to set up the ESB-4 neck for anything like that.

If you de-fretted it, you could probably sand the fingerboard radius to a Fender 7 1/2" radius, which would help. Any more, and at the edges you'd probably sand through the edges of the fretboard. You'd then have the bridge to worry about and you'd need a replacement with individual height adjustable saddles. Which won't be cheap.

With a bow, to play individual strings, you need either a lot of string height above the body or a very narrow body at the place you are bowing, so you can get the angle of the bow right to select just the E or G string to play. You simply don't have that with the ESB-4.

I really don't think it's a good platform for converting to a bowed instrument. You could spend a lot of time and money making something that still doesn't work well or sound very good.

What luck. I knew it was a silly idea but was just day dreaming.
Now a more realistic question: Adjusting the nut height. If my fingers had the grip of a C-clamp fretting the first fret would be no problem. The strings are way too high. I have the bridge where I want it. How high should the strings be above the first fret? I have seen .020" for guitars and guess it is different for a bass and my strings aren't even close to that, .060" at least. I was reluctant to monkey with it for for fear of undoing all my work at leveling the frets but upon consideration realized the nut height doesn't affect anything past the fingered fret. That is set by the bridge height.

I don’t think I’ve ever measured the final string gap at the first fret as I do it all by eye, but basically as low as you can get without the string buzzing on the first fret. I did try and use a nut file as a gauge/cut stop on my last set-up but ended up with the string flat on the fret, so replaced the nut and went back to doing it by eye. I don’t really like it when a specific height is mentioned, as a lot depends on just how much neck bow is set and just how level the frets are (my fret levelling improves as I do more of them, but I occasionally have to re-do the level when I can’t get the low action I know I should be getting). You can often achieve a much smaller gap. However, the smaller the gap, the more risk there is of a first fret buzz, so if going for the ultimate low action, you may go too far, so you need to be prepared to either fit another nut, or do a slot-filling repair job with super glue/CA and baking soda/bicarbonate of soda.

The thicker the string, the bigger the gap needs to be, but with level frets you should be able to get away with the same distance above the first fret as at the second fret when fretting at the first. You can always add a little bit extra to be on the safe side.

Lowering the nut slot height will bring the overall action down, but unless the nut is very tall to start with, in terms of the risk of buzzing, it’s only that first fret when playing open strings that you need worry about. If the nut slots are very tall, then there can be a greater vertical element to the string tension on the neck (adding some bow), which means that when the nut slot heights are lowered, the neck curve may flatten slightly, so you may need to slacken off the truss rod by a very small amount to get back to the curvature you set up before working on the nut.

But it is the work of moments to adjust, and I generally still play around with the truss rod setting and the bridge height after I’ve cut the nut slots to see if I can get the neck a little bit flatter. But then I do like really low actions, so if you prefer a reasonable gap under the strings so you can really dig in, then you may want to leave it well alone. But even with an action that’s generally on the high side, you want to have strings that are easy to fret at the 1st fret. Also, too high here and the strings will be sharp when fretted.

If you’ve set the intonation up before lowering the fret slots, then you’ll need to check that again. As previously mentioned, lowering the slots will bring the overall action down, which means you need less force to fret a string at the 12th fret. This means less change in string tension between the unfretted and fretted condition, so the 12th fret note won’t be as sharp, so the saddle will probably need to come forwards a bit, especially when you have taken the nut height down significantly.