Post by R the F on May 13, 2015 8:56:42 GMT
Yesterday I finished making the bridge and took some photos so that’s where I’ll start this account.
It’s made of laburnum stained black with iron acetate (nails in vinegar) with the grain filled with shellac and then waxed very lightly. It’s very nice to handle and looks like something out of Star Wars but that doesn’t mean it will hang on to the strings when it’s attached to a guitar!
It weighs 25gms and covers, I suppose, about 80% of the area of a more typical design at 4260mm² so shouldn’t give the glue any problems if I make a good job of preparing the surfaces. In fact, those seven little holes you can see should make it absolutely sure that it doesn’t do a Star Wars and set off across the galaxy; they are for ?” dowels which will fix it securely to the braces beneath the soundboard.
That explains the 6 bed-pan-shaped holes as well. Since there are braces under the bridge area, there’s really nowhere inside the guitar that ball-ends can happily settle if the strings are fixed with a more traditional peg system. I cast around a little to solve this problem and then discovered that there are one or two steel-string guitar makers who attach the strings to the bridge itself (not to mention classical makers) so that is what I have done. The holes are slightly angled so that the ball-ends can’t get off the surface of the soundboard when they are under tension. I have also orientated the grain north-south to help deal with the stress that the bridge will need to deal with.
I’ve had to make a special caul to put pressure on from underneath when gluing the bridge in place. It is curved and shaped to avoid the braces and only touches the soundboard itself. Here’s a picture of it.
My explanation for having a Spaghetti Junction of braces directly under the bridge is twofold:
First I was trying to design a bracing system which, on paper at least, seemed to me to more directly confront the problem of the guitar trying to fold itself in half under string tension. I’m not quite sure how the conventional layout deals with 80 kilos of pull (though it clearly does so) so I set about reconfiguring things so that they made intuitive sense to me. Obviously my intuition may be way off the mark but that’s part of the excitement. I just don't like blindly following something that I can't explain to myself let alone anyone else. What I came up with is an attempt to transfer the stress directly from the end of the neck as it enters the box to the sides of the guitar at their tightest curve (strongest point) and then directly down to the bridge area where the the other end of the strings are attached. Now, unfortunately, a guitar should be rather more than an attractive arrangement of heads and necks and boxes that can put up with a great deal of tension; it is also supposed to sound good when played. I haven’t really catered for this aspect of things here so…
...secondly, it seemed to me that, since the idea is to make the whole braced soundboard sing, then – again intuitively and with no evidence or experience whatsoever to back it up – it makes good sense to me to put the bridge right at the point where the braces can take the vibrations and radiate them out across the soundboard. So, rather than put the bridge on a blank patch of soundboard hemmed in by braces, I am going to put it right at the hub of the spokes.
Here is the design that resulted:
And here is a picture of things as they stand today:
This is the first flat-top guitar I have made and I will no doubt look back in embarrassment at my foolish attempt to reinvent the wheel without knowing the first thing about circles but… what the hell (as someone said). Over the next few days I hope to be attaching the bridge to the body and then the strings…
Will it implode?
Will it sound like a drawer full of socks?
Watch this space and find out!
It’s made of laburnum stained black with iron acetate (nails in vinegar) with the grain filled with shellac and then waxed very lightly. It’s very nice to handle and looks like something out of Star Wars but that doesn’t mean it will hang on to the strings when it’s attached to a guitar!
It weighs 25gms and covers, I suppose, about 80% of the area of a more typical design at 4260mm² so shouldn’t give the glue any problems if I make a good job of preparing the surfaces. In fact, those seven little holes you can see should make it absolutely sure that it doesn’t do a Star Wars and set off across the galaxy; they are for ?” dowels which will fix it securely to the braces beneath the soundboard.
That explains the 6 bed-pan-shaped holes as well. Since there are braces under the bridge area, there’s really nowhere inside the guitar that ball-ends can happily settle if the strings are fixed with a more traditional peg system. I cast around a little to solve this problem and then discovered that there are one or two steel-string guitar makers who attach the strings to the bridge itself (not to mention classical makers) so that is what I have done. The holes are slightly angled so that the ball-ends can’t get off the surface of the soundboard when they are under tension. I have also orientated the grain north-south to help deal with the stress that the bridge will need to deal with.
I’ve had to make a special caul to put pressure on from underneath when gluing the bridge in place. It is curved and shaped to avoid the braces and only touches the soundboard itself. Here’s a picture of it.
My explanation for having a Spaghetti Junction of braces directly under the bridge is twofold:
First I was trying to design a bracing system which, on paper at least, seemed to me to more directly confront the problem of the guitar trying to fold itself in half under string tension. I’m not quite sure how the conventional layout deals with 80 kilos of pull (though it clearly does so) so I set about reconfiguring things so that they made intuitive sense to me. Obviously my intuition may be way off the mark but that’s part of the excitement. I just don't like blindly following something that I can't explain to myself let alone anyone else. What I came up with is an attempt to transfer the stress directly from the end of the neck as it enters the box to the sides of the guitar at their tightest curve (strongest point) and then directly down to the bridge area where the the other end of the strings are attached. Now, unfortunately, a guitar should be rather more than an attractive arrangement of heads and necks and boxes that can put up with a great deal of tension; it is also supposed to sound good when played. I haven’t really catered for this aspect of things here so…
...secondly, it seemed to me that, since the idea is to make the whole braced soundboard sing, then – again intuitively and with no evidence or experience whatsoever to back it up – it makes good sense to me to put the bridge right at the point where the braces can take the vibrations and radiate them out across the soundboard. So, rather than put the bridge on a blank patch of soundboard hemmed in by braces, I am going to put it right at the hub of the spokes.
Here is the design that resulted:
And here is a picture of things as they stand today:
This is the first flat-top guitar I have made and I will no doubt look back in embarrassment at my foolish attempt to reinvent the wheel without knowing the first thing about circles but… what the hell (as someone said). Over the next few days I hope to be attaching the bridge to the body and then the strings…
Will it implode?
Will it sound like a drawer full of socks?
Watch this space and find out!
Jo whoever he is.
