Official Luthiers Forum!

Hi everyone-- please pardon me if this is slightly off topic or in the wrong section. I'm putting a new bridge on a violin for a lady at work. This violin is not anything of monetary value, they would just like to have it back in one piece and semi-playable for their daughter.

I'm confused about which way the bridge should face. The old bridge is cracked and disfigured, so I can't really get a good read on it. One side of the bridge is tapered and the other is square. I've looked online and gotten an answer of "the tapered side should face the tailpiece." At first that seemed to answer my question, however, I'm too analytical and if I look from the headstock to the tailpiece, *BOTH* sides "face" the tailpiece. (Darn relativity.)

So, here's the question-- is the order I should be looking for either A or B:

A: end of fingerboard-- tapered side-- square side-- tailpiece
B: end of fingerboard-- square side-- tapered side-- tailpiece

Fortunately, I have the jig to help shape the feet to the contour of the top and some extra time, so I think this is something I can do... just need to ask folks with more expertise how to go about this.

Thank you to everyone for any and all responses!

John

Here is a website with details:

http://www.musictrader.com/string4m.html

_________________
Build log

The side of the bridge that faces the tailpiece should be 90deg to the top, the front of the bridge slopes.

Colin

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Option A

_________________
Tomasz Cudzich

Howdy John,
Option A is the correct answer as others have said. You also need to fit the feet of the bridge to the top. It is done by laying sandpaper on the top where the bridge will be and using a jig to hold the bridge upright, sand lightly from front to back until you get the correct radius on the feet as the same as the top. All surface of the feet should contact the violin. Draw a light pencil line from the inside points on the F-holes across the top of the violin. The feet of the bridge should be centered on that line.

Hope this helps

_________________
"After forty-nine years of violin building, I have decided that the search for a varnish is similar to the fox hunt. The fun is in the hunt."
Jack Batts Maker and Repairer of Fine Violins

The point of the taper is that the vector of string pressure falls within the foot of the bridge, even though the break angle is sharper on the tailpiece side. So the correct answer, as others have said, is A. Face it the opposite way and the bridge will tend to tip over toward the fingerboard.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Thank you everyone! Option A is indeed what I thought was correct and what I went with. Fortunately, the website I was pointed to (thank you!) had an additional bit of information on it about centering the "heart" of the bridge. To that end, I taped my sandpaper to the top and used my wheel/clamp jig to slide it back and forth across the sandpaper until both feet were completely matched to the contour of the top. I kept going until I removed sufficient material from the feet to center the heart at the projected final height of the bridge.

This may be wrong, but it made sense to me... the old bridge was cracked laterally through the middle as if it folded over from the tension of the strings. I'll try to post pictures a little later if anyone is interested. It seemed to me that the old bridge was a little *too* thin at the top and this may have contributed to it "folding." Now, this instrument was "Made In Nippon," so although it is at least 50-60 years old, it will *never* be considered a finely crafted vintage violin. To that end, my goal was to make it stringable, semi-playable, and as stable as I could make it. So, I left the bridge a little thicker than the previous bridge and actually rounded the top as you would a guitar saddle. This may be incorrect practice for a violin, however, it seems logical to me to do so. With a thin bridge top you get a small surface area for the string to bear on and this would also be the case with a rounded bridge top.

I know, I know... probably very much the wrong thing to do. The family I am working on this for only wanted two things: 1) put the violin back together in as good as shape as I can without major surgery and 2) get it playable enough so that their daughter can have the violin her Grandfather bought overseas many years ago to play when she grows into it, even if it cannot be a professional quality instrument.

I'll try to get some pictures up of my work soon...

JC

I don't do violin setup, but I think that is way too rounded on top, which also negates part of the purpose of the thickness taper. Kind of a chunky looking bridge to begin with. How does it sound? Is it tending to tip toward the fingerboard, or dig its feet in along the edge toward the fingerboard? If it's working well, it may be best to leave well enough alone.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

I'll be honest, I don't do violin setup either. The bridge blank came shaped pretty much like that from Stew Mac. It doesn't seem to be digging into the top at all and is not exhibiting any tendencies to tip towards the fingerboard. As for how it sounds, I don't play violin at all so I'm not a good judge there, but plucking the strings yields a clear note that is not muffled at all.

Fortunately, this doesn't have to be a world class setup on this violin. Otherwise, I would have politely declined.

A few observations. Just as an over heavy bridge will kill the response on a guitar the same is true for a violin, so if it was me I'd try and lose some of the weight off that bridge. And yes Howard is right about the shape of the top it should be relatively flat on the top with the strings breaking at the front of the bridge. Take some measurements, the top of the bridge should be about 1.25mm (.050") wide and the bridge should taper down to about 4mm (.160") at the base. Also try to round off the appertures by chamfering the edges of the holes, and by arching the base rather than leaving a flat shape. Remember that the scale length should be 327mm, so that means that with the strings breaking off of the middle of the bridge you'll have to move it forward, this may change the position of the bridge relative to the soundpost just behind the treble foot of the bridge, this can also change the tone of the violin.

Colin

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Wow John,
Nice job on rounding the top! And you do have it oriented the right way too.
But, as Colin and Howard has already commented, it is a bit beefy. You know when you order a bridge it is a bridge blank and should have a little carving and sanding applied.

My only comment is: the final thickness of the feet should be right at 1 mm. You can hollow the bottom of the feet with a convex edge scraper slightly to help the feet fit tightly all around when under pressure from the stings. You can slap the bridge on your belt sander to thickness it to the dimensions Colin gave you. Of course watch your fingers when doing this...ouch!
The E string clearance at the end of the fingerboard should be from 2.5 to 3.5 mm. The G string clearance will be approx 4 mm.

It would be fine just like it is if that is what the owner wishes. Or, you can whittle some more on it if you like. If so, smooth the top flat with a file then chamfer the edge 45 deg (narrow bevel) all the way around the top. File very shallow grooves for the strings to ride in rounding them slightly downward towards the tailpiece. No deeper than 1/3 the string diameter. Lubricate the grooves with graphite from a pencil. You could raise the under arch with a knife to match the curve of the violin so it doesn't appear flat. You could also whittle away at the heart and kidneys to give it your personal touch too.

Hope this helps. Just some of the things I do to them.

_________________
"After forty-nine years of violin building, I have decided that the search for a varnish is similar to the fox hunt. The fun is in the hunt."
Jack Batts Maker and Repairer of Fine Violins

Wow-- and I thought working on guitars was hard! Thank you all for your kind replies. I'll try to tinker on this a while longer. Fortunately, we're in no hurry. I've had it for a year trying to work up the nerve to do this, and the girl who it will go back to is now eight years old, so it will be a while before she'll grow into it.

Thank you for all the measurements as well. This is all new to me, especially working only with hand tools-- I live in an apartment and have no power tools aside from a dremmel. Good thing time is not of the essence, huh? Thanks again!

First: there is no agreed on 'right' way to cut a bridge, although most violin makers and repair people will tell you that _their_ way is, in fact, the _only_ right way to do it, and that any other way is terrible. That said, that's a pretty bad looking bridge by any standards....

Here's a few things about my 'right' (or 'wrong', depending on who you talk to) way of doing it.

1) Fit the feet. I was taught to make the feet low: that is, to remove as much wood as possible from the under side of the feet, rather than the top. The ends should be no more than 1mm high. How much you can take off the bottom of the feet will depend on the shape of the fiddle top. If it's really curved in the center then you will have to remove more wood from the inside, and the outside end of the feet will be thicker than 1mm when you get the inside right, so you will have to trim the outside down a little on the top.

You can use sandpaper initially, but I like to finish up with carbon paper and a scraper or knife. Some old timers used to scrape the varnish off the top where the bridge sits, which over time gives a a 'nice' dipin the top that is darn near impossible to fit any other way. You got lucky.

2) Trim the curve of the top to the correct shape and height to give the action you want. As with everything else, this is a matter of opinion, but I usually have the low G string about 5mm off the end of the fingerboard, and the E more like 3.5, iirc. I confess it's one of those numbers I look up when I need it, and I don't have it on hand right now.

3) Thickness the bridge. Make sure the back side is flat. It will nornally be at a right angle to the top or close to it. The bridge thickness at the feet should be about 3.5mm, and it tapers up to 1.5 to 1.7mm at the top edge. I make the front of the bridge (the part facing the fingerboard) in a 'clamshell' shape, so that the top edge has a uniform thickness. With a bridge in this style the back side of the feet will be on the line drawn from one inside F-hole nick to the other. That's what the nicks are for.

I do this thicknessing with a sharp block plane, holding the bridge in a quicky holder. Lay the bridge down on a piece of scrap soft wood on it's back. Scribe along both sides of the bridge, marking the taper on the block. Make a saw cut on the scribe lines, and remove the waste wood in between to make a flat platform that is about 3mm below the surface of the block at the 'feet' (narrow) end of the taper, and rises up to the surface at the 'top' (wide) end. Make sure the bottom of the taper is flat! Stick the bridge in, back side down, and push it down toward the feet so that it is wedged in place. Now you can plane, file, or sand the upper (front) surface, so long as you don't plane, etc., from the feet toward the top.

4) Trim the bridge to shape. This is somewhat a matter of style, but it also effects the sound. I like to trim a little bit of wood out on the underside of the 'legs', so that the curve there more or less matches the arch of the top. Round off the upper edge, as you did, and make _very small_ notches where the strings go. These should only be deep enough to hold the sttrings in place, but not as deep as the diameter of the string. These are normally filed, and then lubricated with a touch of graphite from a pencil. Other than that there are a lot of styles of cutting a bridge, and I can't go into it all now. A well cut bridge has a certain elegance to it, and you'd be surprised at how light some of them are.

All of this work calls for _sharp_ tools, and a light touch.

Argh enough already - after Barry and Colin showing off fiddles I am finding myself looking more often and often at violin wood and related tools - and now this bridge talk. It wasn't enough that i already had a guitar tool shopping list of about 2000$ plus the WAS relief

_________________
Build log

LOL....yeap, your catching the fiddle bug. Actually it doesn't take all the tools and jigs to make a violin as it do to make a guitar. You probably have everything you need already. Maybe get a few #7 sweep gouges and you're set up.

_________________
"After forty-nine years of violin building, I have decided that the search for a varnish is similar to the fox hunt. The fun is in the hunt."
Jack Batts Maker and Repairer of Fine Violins

I need to adhere to a method - seen a few online - but so far with many jigs - which I hate making. For the couple guitars i made so far I kept it as simple as possible so i will probably do the same with the fiddle.

_________________
Build log