Violin Forum/Message Board

[John Cadd]

There are several references to bridges OTF (on this forum ) but having them "loose" makes it easy to miss them.This is to pull a vital topic under the same roof.
Here`s the main question. What is the best way to fit the feet of a violin bridge? ( ie practical steps to achieve the result ).
Please add in references to the wood grain and shaping the top edges of the bridge feet if you would be so kind.

[rs]

The key is a good sharp knife. For the bridge, I want the knife as sharp as for any other step of making of the fiddle.

If the knife is not razor sharp, I want to EASILY be able to shave with it, it tends to dent the feet instead of cleanly shave them, and it also tends to break off the corners of the feet as the knife ends up dragging instead of cutting. If the corners break, the bridge is ruined. If the knife isn't extremely sharp, I will also certainly end up cutting my thumb.

I place the bridge on the belly, after it has been filed and scraped to proper thickness, and make a fine pencil line on each foot following the contour of the arch of the belly. This is similar to outlining the contour of the bass bar when fitting it. If the knife is extremely sharp, I can then turn the bridge perpendicular to my eye and gently draw the knife to me following the line. I do each side this way. The cut is generally clean and straight. If it fits well, the bridge should stand alone on the belly without any strings. NO gap at any point should be present between the feet and the belly even without string pressure. This way, when string pressure is applied, the pressure will be evenly distributed. If I miss on the first try to get the fit perfect, there is generally enough wood left in the feet to re-fit. Once it is fit, I then thin from the top down until the feet are very thin. I do this with a thin extremely sharp knife as well. As I will certainly end up removing some more wood from ABOVE the feet, I found it easier to fit the feet first to the belly and then trim down. I usually make my own bridges and this saved me some headache from broken corners. Once this is done, I fit the top curve of the bridge for the height needed.

Hope this helps and best wishes
_________________
Randall Shenefelt

[rs]

One other side note, as the shaping of the top edges was omitted in my post, I found it easiest to work the knife from the upright out AND upward. The little "lift" that the ends of the feet have is actually easier to cut than making the top of the feet flat. I place the tip of my knife in the "hole" and simply whittle away from the upright and up at the same time. The key to this is to have an extremely sharp knife, and avoid hesitating, that is make sure each cut is precise and begun as if it is on purpose.
_________________
Randall Shenefelt

[Andres Sender]

Michael Darnton's articles on violin setup for American Lutherie magazine include excellent instructions on fitting a bridge. They may be tracked down via the GAL website at www.luth.org --they've been collected into one of the 'Big Red Books'.

[John Cadd]

Andres The reference looks as if you need to buy the whole book. Is that the case? RS has described the traditional way.Do you know if this is basically similar to the book method?Just a rough impression would be OK.

[John Cadd]

If you have a safe platform to hold the violin you can use this method.
I assume the violin is held steady and horizontal and fit an adjustable block of wood below the end pin to use as a guide for a wooden sanding bar.( 10 inches long ,2 inches wide ,1 inch deep)
The bottom surface away from the bridge is shaped to a curve or a "V" to run in a groove in the end block.
The bridge can be fixed to the sanding bar so that the exact bridge angle relative to the top plate is maintained.
Set the bridge feet between the f hole nicks in a way so that the back of the bridge is vertical to the belly.Check that the vibrating string length is correct for the size of the instrument.If you are not sure what that length is you may not be playing in tune.You must check what that length should be.
The sanding bar should have a square cut end so that the bridge angle will be adjustable by altering the end block height. The end block top should have a groove in the centre which will match the end of the sanding bar.This will allow the bridge feet to settle evenly on the belly and will guide the bar as it moves to and fro.
By holding fine abrasive paper across the belly with the left hand
and rubbing the sanding bar and bridge to and fro along the grain direction between your thumb and finger (left hand) you can achieve a good fit at the best angle. Always avoid rubbing across the belly.Constantly check that the underside of the abrasive is free from grit or dust to protect the varnish.
This is done at the final stages of fitting.The method of fixing the bridge to the bar is up to the maker (or player) himself.
That is the broad outline of what I do.
To be certain of a complete contact cover the bottom of the bridge feet with pencil lead .Then wnen all this is sanded off you have completed the fit.

[John Cadd]

There is a site that covers bridge fitting and he uses the same method I described above.Completely independant of each other.Here`s the bit I wanted to add.Try to pick your bridges personally rather than having them posted to you.The thing to look for is the wood grain.Look closely at the edges.See if the grain runs straight up and vertical both sides.The grain should be parrallel with the side facing the player.(The bottom of the violin.)
You should see long patterns on the players side .There is some disagreement about which side the maker`s stamp should be.If you follow tradition it will be facing the player.That`s the vertical side with long patterns which must be kept flat from top to bottom.
Be very fussy when choosing your bridges.Don`t take anything substandard.

[John Cadd]

One piece of info when you fit a bridge.--The edges of the bridge feet should be at least one millimetre thick. (1 to 1.5 mms)
When you work on a bridge try this tip.----Fit a block of wood about 1.5 or 2 iinches thick in the vise .Have the block standing upright so the top will make a working platform.This is done standing up.
When you shape the taper of the top section (with a diamond nail file) hold the bridge onto the vertical back of the block and you look straight down (feet left ,top right). When you trim the bottom of the feet hook one foot on the vertical front corner and cut towards the block.(Always cut the bridge feet towards the centre of bridge).
Hope that helps.

[jethro]

Amz. :
I use your method too. I made a little trolly. A 3 leged thing with felt on the feet to let it slide easily. A sandwitch thing on the end to hold bridge.
I carve the brige with new exacto blade. cut the feet on bottom roughly
with dremel to approximate height. Then sand with 220 and 400 and
600 grit paper on belly. Last step for feet is that I draw a margin arround
the inside of the foot underside. Then I very lightly scrape in the inside
of the mark. this slightly hollows the very center and leaves a perrimeter
of contact. This is just in case the foot should turn out slightly convex
from it moving a little durring the sanding stroke. not sure if it is needed or if it helps....... just something I have done.
Your thoughts ?
Tim

[John Cadd]

Hello Jethro .It seems ages since I looked on this site.Giving you all some peace at Christmas. The trolley with felt seems mysterious.That would be guided by the belly as it moved.Does it fit behind the bridge?(player side).Can you get a vertical back angle on the bridge? The belly slopes down hill more that way. I have heard of the slight hollowing .I haven`t done that myself but will try it to see. The vertical is judged from the bottom surface of the belly as there are so many ways to get a funny result. The violin is resting on a heavier oblong frame as I think there is a danger of a sleeve or something catching and sending it to the floor. Brain surgeons have that problem all the time." Sorry mate ---let`s just get you back on the table so we can stitch you up".
The trolley is a lot shorter than my guide block.I find the wood that length is easier to hold than something on the belly.I used to use a shaped block and rub sideways but that never got such a close fit at the foot edges. Have you tuned the bridge using the Snowy Tree Cricket recording? I can recommend that.