Violin Forum/Message Board

mr_violin · Member Joined: 15 Sep 2009 Posts: 52 Location: Chicago

How big to make the base bar

Hi, I am a new member here, but I have read most all post on here.

Thanks to all of you for taking the time to help beginners like me. I have already learned a lot!

I am starting out by buying old broken, mostly cheep factory violins to repair.
Most of them I am completely rebuilding.

One thing I cannot find much information on is the base bar.

What is the formula to know how long to make it. How high to make in the middle and the shape of it.
I am working on some cheep!! Soft-top violin. I read somewhere that the base bare would have to be a little bigger in that top. Bigger than what? How much bigger.?

Also I am working on violins that are ½ ,3/4 ,7/8, and 4/4. How do I figure the size for the smaller ones?

I bought about 25 old broken violins off ebay. I bought about 50 violins from China.
I plan to learn from trying to repair and improve the violins I have before I try to make one of my own.
I hope in 10 years when I retire, I will be making violins of good quality.

If I can figgur out how to post the photos, I will show you some of my work.

Email: Mr_violin@hotmail.com

Michael Darnton · Posted: Thu Sep 17, 2009 11:07 pm Post subject:

I use a simple plan that is based on something I got from the Carl Becker shop, who get full credit for it. The basic idea is to measure the bar height including the top thickness, with a graduating caliper. Divide the bar into eighths (nine pencil marks, including the ends) and the thickness of top plus bar is 5.0mm, 7.6, 10.2, 12.8, 14, 12.8, 10.2, 7.6, 5.0, from one end to the other at each mark.

It's simple, gives exactly the right profile, and compensates for top thickness. I start the bar 40mm from both ends, and it's 5.5mm wide, 1mm inside the outside foot of the bridge, and 12mm from the center of the upper bout and 15mm from the center of the lower bout.

That's all there is to it, and for smaller instruments multiply by .925 for each successive size downward.

mr_violin · Member Joined: 15 Sep 2009 Posts: 52 Location: Chicago

Thanks Michael for the quick and simple answer to my question.
I have a ton respect for you and your thoughts on the subject of violins.
I always look for your comments on every subject posted on here.

That formula makes it very essay to figure out.

Now do I get from your answer, that you don’t think there is a need to make the base bar any affront for some of these cheaper old factory violins? “ softer tops”

What about the violins defend styles of arching.
I know I could experiment, but I’m thinking some of you have already done that.

I have no time to try and reinvent the wheal.

Michael Darnton · Posted: Fri Sep 18, 2009 7:49 am Post subject:

I don't find the bar too useful to compensate for errors in arching or wood. You can try if you like, but it hasn't done much for me. The standard rules are that a bar farther out towards the edges stiffens the top, and one inward loosens it, as does making a smaller or looser bar. My experience is that doing these will neither help nor hurt, so go ahead and try if you want.

You do want to be careful about the bar ends--too much bar at the ends, or having top thickness that sneaks out from the blocks to the ends of the bar--will hurt, as will rotating the bar too much beyond the 12 and 15mm location points. Either will choke the tone, but not stiffen it.

CT Dolan · Member Joined: 29 Jun 2008 Posts: 143

Michael, you have no idea how much you're helping the rest of us. Man, your generosity is overwhelming. Thank you.

actonern · Super Member Joined: 15 Aug 2007 Posts: 444

Michael, you have no idea how much you're helping the rest of us. Man, your generosity is overwhelming. Thank you.

Amen to that! Just about everything you post goes in the binder...

E

Michael Darnton · Posted: Fri Sep 18, 2009 1:00 pm Post subject:

Thanks.

mr_violin · Member Joined: 15 Sep 2009 Posts: 52 Location: Chicago

Thanks again Michael,
I know there is definitely a limit to what you can do to improve these cheep violins. I am having fun fixing them up and selling them to kids just trying to learn the play. You know most of them can’t afford to pay a lot of money for a violin. I am learning a lot so far too. Repairing broken necks, peg box cracks, replacing neck blocks, end bocks and adding 4 corner blocks were there never were any, Regraduating the plats, and repairing all kinds of other cracks in the tops and backs.
I learned most of how to do all this from this forum. Thanks again to all of you!!

Geemac · Posted: Fri Sep 25, 2009 3:44 pm Post subject:

When the base bar is in place, what should the height of the base bar be at the center? 14mm? More?
_________________
GeeMac

Mark Sullivan · Posted: Fri Sep 25, 2009 4:08 pm Post subject:

If your following the method Mr. Darnton noted via the Becker shop, the bar ends up 14mm minus the thickness of the top at the middle.