Violin Forum/Message Board

Geemac · Posted: Mon Jul 28, 2008 11:16 am Post subject: Base bar

While repairing violins, I have seen base bars that are four inches long up to the complete distance from end to end of the violin.

What are the length width and height of a base bar supposed to be for a 4/4 violin?
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GeeMac

Jack H. · Posted: Tue Jul 29, 2008 2:47 am Post subject:

The length should be 8 cm short of the length of the table at the locus of the bass bar. 4 cm form the top and 4 cm from the bottom. andything else is either baroque or just poorly made. the width is around 6 mm, although every now adn then I put in one that is a tad thicker. the height at the center is around 11-13 mm depending on the arching adn table thickness and flexibility, tapering in a curve to 3mm at the ends.

Geemac · Posted: Tue Jul 29, 2008 9:02 am Post subject:

Thank you, young fellow.
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GeeMac

Jack H. · Posted: Wed Jul 30, 2008 9:44 am Post subject:

Happy to be of help old timer!
Do you need any hints on setting the angle of the bass bar?
Just let me know.
J

Geemac · Posted: Wed Jul 30, 2008 10:32 am Post subject:

As far as the angle is concerned, I set it to follow the path of bass string.
Is that correct?
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GeeMac

Jack H. · Posted: Thu Jul 31, 2008 12:41 pm Post subject:

not unless the G string follows the bass bar.
Once th etop is off and the old bass bar removed adn the area cleaned, you measure from the center joint to the widest part of the lower bout, write the number down. Then do the same fo the upper bout at its widest.
Write that number down too.
divide both numbers by seven, write the numbers down.
mark of the measurements that you got from the 1/7 of the distance on the inside of the table. Als draw a line in pencil for the mensur between the ff hole notches.measure from the inside of the table at the mensure 19.5 mm. this is where the outside line of th ebass bar will be, adn the 2 points on the upper and lower part shows where the inside line of the bass bar will be. it is more important for the outside edge to be at 19.5mm on the mensur than the inside edge to be on the dots of the 1/7 measuremtn. if needed, the bar can be moved inside or outside to hit the mark at the mensur, but keep the angle provided by the 1/7 marks.
if you have to move the BB 1 mm, just make sure you move the marks each 1 mm.

Have a blast!
Use chalk to fit, the bass bar should be perpendicular to the plane of the lower edge. no tilt.

Let me kno whow it goes and I will give you more measuremnets when you are ready to cut it to shape, adn more hints for gluing.

Jack the Young.

shsu · Junior Member Joined: 31 Jul 2008 Posts: 1

I am rebarring an odd old violin that the distance between ff holes is narrow (35 mm), The normal way to position the bar you described above just doesn't work. To get 19.5 mm, the bar needs to rotate to avoid exposing to the F hole upper eye and is way too inclined. Shall I,

1. Do as you said anyway, ending up a very inclined bar.
2. Move bar outwards as standard method. Expose bar to the upper f eye and drill out the exposed area.
3. Avoid exposure and try to get close to 19.5 mm. I can get 19 mm with somewhat large angle.

Thanks... Rolling Eyes

Geemac · Posted: Thu Jul 31, 2008 11:09 pm Post subject:

oops - I have already glued it into place. Oh well. There'll be more Smile

Stay young and keep having fun
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GeeMac

Jack H. · Posted: Fri Aug 01, 2008 6:14 am Post subject:

Jack H. · Posted: Fri Aug 01, 2008 6:15 am Post subject:

Geemac · Posted: Fri Aug 01, 2008 8:28 am Post subject:

I glued it into the top roughly along the line of the "G" string and then I glued the top to the sides and bottom. Like I said, I'll do it on the next one.
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GeeMac

Geemac · Posted: Fri Aug 01, 2008 11:09 am Post subject:

I'm 63 - You're still a kid Smile

I broke the glue holding the top in place. I could email you a picture if you wish.
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GeeMac

Andres Sender · Posted: Fri Aug 01, 2008 2:02 pm Post subject:

Jack, some very reputable professional shops orient the bar perpendicular to the arching to avoid the effect of a curved bar.

I'm curious to track the 'bar perpendicular to lower edge' idea, can you tell me where it comes from? Thanks!

Jack H. · Posted: Fri Aug 01, 2008 3:25 pm Post subject:

Andras,
I learned it many years ago, even before I saw my first copy of Weishaar.
Never saw an angled bass bar in a nice instrument (read non factory) until a few weeks ago when I opened a Guido Maraviglia cello named Napoleone that he made in 1989 at the age of 80. The top was baked wood, incredibly tight grain and a 30 mm tall bass bar that had 4 grain lines and a curve totally rounded and set at an angle.
It sounded like a cannon, with big warm tones too, but the owner was sure something happened. so we replaced the bass bar and made it more normal, adn it sounded even better. This does not mean to say that an angled bass bar doesnt work.

What are the effects of a curved bass bar? that it has one side longer than the other? When it is perpendicular it is providing maximum resistance to the forces of the bridge.

ollieken · Posted: Sat Aug 02, 2008 3:07 pm Post subject: Bass Bar

Can a bass bar that is not heavey enough say too much taken off of it
make a violin easy to note barely have to touch the string .Even the fine tunner has to be turned down a lot to change the sound not like other violins .
It is fairley loud like the thing is not stiff enough I was thinking of
putting more varnish BYTW I tried different strings light strings don't work on it Plates too thin maybe ? Any thoughts anyone . Ken