Bridge Idea

[Dward13]

I’ve always had this idea for an electric guitar bridge that was adjustable, but was essentially solid with no moving parts.

Also, with a relatively large mass. 

The idea being it would be beneficial in terms of sustain.

Admittedly it would be a tedious pain to adjust, but if it improves sound it might be worth it. (That’s my question to you)

Made this drawing of the basic idea. 

The six bridge pieces would be held to a base with screws and would be adjusted forward and back via. a slot in the piece and up and down by making the initial piece thicker or thinner or with shims.

The base would be screwed directly to the top. 

I’m thinking brass for the material.

Let me know what you guys think, is this a viable idea worth exploring?

Has it been tried before or is it currently in use?

One related question: Is the angle made by the string passing over the bridge critical? 

What should that angle be?

[curtisa]

ABM's 3256 bridge has a similar sort of look. Hipshot also make replacement bridges for some models of Ibanez units that share similar features too.

Where do the strings lace through? The intonation lock screw would presumably get in the way of the thru-body string hole in certain positions?

Do you need to consider some way to adjust the action too?

 

6 hours ago, Dward13 said:

The idea being it would be beneficial in terms of sustain.

Admittedly it would be a tedious pain to adjust, but if it improves sound it might be worth it. (That’s my question to you)

Impossible to predict. I know a lot of people have opinions surrounding more mass at the bridge = better tone/sustain, but a lot of that tends to be subjective and really difficult to quantify.

 

6 hours ago, Dward13 said:

One related question: Is the angle made by the string passing over the bridge critical? 

What should that angle be?

In an acoustic guitar there is a correlation between string-to-saddle angle and the sound produced, but that has a lot to do with getting the top 'moving' in reponse to the motion of the string. Too shallow an angle and the sound tends to be quite thin and lifeless. Too steep an angle has a detrimental effect on the top of the guitar, as the amount of downward pressure exerted on the saddle can deform and/or damage it over time - it might sound absolutely stunning until the top collapses. A solid body electric guitar however probably doesn't share these traits and limitations so much and you're more free to experiment as you wish, but I'd probably recommend at least *some* downward angle (maybe 15 degrees???), if only to stop the string from sliding laterally across the break point of the saddle under normal playing or minimising any chances of poor contact with the saddle leading to weak string response.

I would point out that unless the string securing method somehow 'moves' with the intonation position of the saddle, the break angle will be different for each string depending on the intonation compensation position (think of a Strat bridge for example - the low E string might have a 45-ish degree angle behind the saddle whereas the high-E string might be 20-ish degrees). Another perspective to consider is that each string on a Floyd Rose pretty much passes through a 90 degree bend over the exact same distance. What that really means for a tonal comparison I have no idea, as the two bridges and how they're coupled to the body are completely different.

You might want to have a look through this thread from about a year ago, in particular this post where I attempted to compare the difference between top loaded strings and thru-body strings, thereby changing the saddle break angle. There are some A-B recordings attached and some rudimentary sustain comparisons. There might be something in the steepness of the saddle break angle, but I don't know that I'd call it a night-and-day difference. Make of it what you will

[ADFinlayson]

The babicz tele bridge has a similar design in the way the saddles are locked down, bit of a PITA to adjust tbh. 

[Bizman62]

At first glance that looked great. But...

As @curtisa said adjusting the action would be challenging. Radiusing the base to match the fretboard would be a no-brainer and even getting the action right by filing the base lower for a perfect action is doable. But if you'd find out that a new set of strings or a fret job or a change in climate would require raising the bridge, how would you do that? A shim? Or in the opposite case, how would you lower the bridge? Filing more?

Agreed, I've rarely adjusted the bridge of my guitars after I've got the action right. Also, on acoustic guitars the bridge bone has no other adjusting other than filing. But the bone has to be replaced if you need to raise the action for instance after a refret.

 

[curtisa]

12 hours ago, ADFinlayson said:

The babicz tele bridge has a similar design in the way the saddles are locked down, bit of a PITA to adjust tbh. 

Loosening the saddle lock screws to adjust the intonation on the Babicz bridge doesn't take much time in comparison to the process of setting the intonation overall though. And once intonation is set you generally don't need to go back and fiddle with it again on a regular basis. The Babicz design is also well thought out in that they position the locking screw for each saddle slightly offset from the string path so you can get an allen wrench in to undo it without slackening off the string first. Can't do that on a Floyd Rose for example.

[Dward13]

Reworked my idea a little, don’t know why it never dawned on me before that the screws could be in front of the bridge points.
Seems like this would open several possibilities for string loading.
The base would remain a flat piece with action adjustments made with bridge pieces of different thicknesses and/or filing.
(I’m assuming for the sake of argument that you have access to a variety of bridge pieces of different thicknesses.)

15 hours ago, curtisa said:

Impossible to predict. I know a lot of people have opinions surrounding more mass at the bridge = better tone/sustain, but a lot of that tends to be subjective and really difficult to quantify.

I’m reminded of a time in the 70’s when I worked with an old guy who had a violin shop.  
He had one long time customer who had gone on to become a professional musician who played in major orchestras.  
She one told me that she would sometimes be asked to play violins so someone could pick one to purchase.  
She would stand behind a sheet and play; the person would then pick blind judging them by the sound only.  
She said “Of course if I liked one violin over the other I would play well on it and poorly on the other”.

[curtisa]

As per my previous comment regarding the Babicz Telecaster bridge, you could shift the locking screws slightly to one side to allow you to get a wrench on to the bolt head without the strings being in the way.

Action adjustability is still a limitation. Shimming is fine as an option, but you have to have a stash of shim material handy to use in the first place, which a lot of people wouldn't necessarily. And removing material to get things lower is somewhat permanent and destructive too.

What about having your baseplate resting on a separate sub-assembly that can be raised and lowered using a pair of grub screws at the forward-most corners? At least that way you could get back some degree of coarse adjustability for the whole bridge assembly.

[Bizman62]

I was thinking similarly about turning the bridge around but then I started to think about height adjustment being a bigger issue.

As for shimming, my first thought was to have a large shim under the whole bridge - or several shims for that matter. A large plate secured with screws in each corner would be easier to align than tiny strips under a single screw.

A pair of scrub screws to raise either the front or back edge sounds like an option. However, that would require something harder than wood underneath. And that would change the entire design.

[Dward13]

Played a little more with design of the pieces.

My question today is "How far ahead and/or behind the actual scale length is needed as intonation adjustment".

i.e. For a 25 in. scale would adjust-ability between 25 1/4 to 24 3/4 be enough or perhaps +- 5 mm.

[curtisa]

That might depend a bit on what spread of scale lengths and string gauges you're planning to cater for. Thicker strings tuned low on long scale lengths will need more compensation than skinny strings tuned high over short scale lengths.

If in doubt just follow in the steps of others. A range of 10-12mm is generally as much as you can get from a Strat bridge and most of their derivatives, and is probably a good bracket to aim for.

 

5 hours ago, Dward13 said:

How far ahead and/or behind the actual scale length is needed as intonation adjustment"

The range of intonation adjustment should never ever ever everevereverever etc take you less than the scale length. Compensation is always, without exception, an increasing of string length. The saddle will only ever need to go more further away or less further away from the nut.

A guitar that wants to intonate by compensating less than the scale length is...well...broken

[Bizman62]

5 minutes ago, curtisa said:

Thicker strings tuned low on long scale lengths will need more compensation than skinny strings tuned high over short scale lengths.

Just in case you're interested in the "why", it's because a thick string is stiffer than a thin one. For wound strings it's the core that matters. There's an angle where the string leaves the bridge or nut and it takes some distance for the string to straighten. For perfect pitch you have to uniform the straight parts of the strings by moving the curved ends.

[curtisa]

That's not the primary reason compensation is applied, although it does contribute to the overall requirement to do so. The main reason is that depressing the string to the fret bends the string, thus raising the pitch. The compensation required to offset this bend/pitch rise is to make the string length slightly longer, so the saddle has to move further away from the nut.

[Dward13]

14 hours ago, curtisa said:

Compensation is always, without exception, an increasing of string length.

Thanks, didn't know this.

My last build I sort of shot for the middle of the adjustment range on the bridge and will probably need to move it back a 1/4 in. or so to get the intonation right.

[Bizman62]

Edited the illustration to hopefully make it make more sense. The light blue "nut" marks more or less the measured intonation point for an imaginary blue string that has no stiffness. The pink "nut" marks the intonation needed for a thick and stiff string. The pink line marks the area that needs to be intonated because it doesn't vibrate due to being curved.

As you noted I used the word "stiff". Stiffness is the crucial thing here, not thickness - although thickness usually adds stiffness. But it depends on the material used as well. Steel is much stiffer than nylon, for example. And if you take a nylon string set and look at the wound strings you'll find out that the core of them is multi-threaded which makes the unwound G string the thickest of a set. In steel string sets the core of the wound strings is a single wire. That's why classical guitars don't have a compensated bridge.

[curtisa]

34 minutes ago, Bizman62 said:

That's why classical guitars don't have a compensated bridge.

Not at all. Classical guitars do have compensated saddles, it's just that the compensation applied tends to be an average lengthening of the overall scale length by an equal amount. 2-3mm extra is common. The amount of compensation deviation between each string is much smaller too, which is why a perpendicular saddle is more acceptable on a nylon-strung guitar. An independently compensated 3rd string is also not entirely unheard of either.

But again, the amount of compensation required because of loss of vibrating length at the absolute ends of the string due to stiffness is far outweighed by the compensation required to offset bending/sharpening of the string when depressed. Nylon-strung instruments are just less affected by this phenomena compared to steel-strung counterparts.

[Bizman62]

10 hours ago, curtisa said:

Nylon-strung instruments are just less affected by this phenomena compared to steel-strung counterparts.

Again, a native English speaker nailed it in one single sentence.