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Bridge weight and placement
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=3460
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Author:  GregG [ Fri Oct 07, 2005 11:40 pm ]
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I weighed my bridge(minus pins and saddle)before gluing, it weighed approx. 28 grams. When you guys mention the desired weight of your bridges, does that include pins/saddle? If not what do you consider normal weight for those two additional items? I ask this question because I noticed on my first build that a small adjustment in weight on the bridge can really affect the sound/tone of the guitar. It seems to me that the bridge is just another critical area to consider when building a guitar.

Thanks,
Greg

Author:  Matt Gage [ Sat Oct 08, 2005 12:11 am ]
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Hi Greg, Yes weight and density do have an effect on the tone. I noticed the same thing when I switched from belly bridges to pyramid style.

just remember that the thinner the bridge, the better the chance that the strings will pull it off over time.

thickness and desity vs. gluing surface area...the classic struggle.
over time I have found that the belly bridge pretty much gets it right.

Author:  Colin S [ Sat Oct 08, 2005 12:31 am ]
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I try for 25gm or less for the bridge, without saddle and pins. I find that this is easily possible with BRW (sometimes down to 20gm) and a do-able with EIR, I wouldn't use a bridge that exceeded this weight. I think Sylvan is the expert on bridge weight as he has a record of the weight of every bridge he has made, but I think aims for about the same.

Colin

Author:  Paul Schulte [ Sat Oct 08, 2005 2:51 am ]
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Sometimes heavier is better, sometimes lighter. I think that If you stay within the "standard sizes" of bridges that are commonly out there and accepted by musicians used on the size of guitar you are building you should be okay. Quantifying guitars is a steep and slippery slope, watch your step!

Author:  Michael McBroom [ Sat Oct 08, 2005 5:33 am ]
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Hi Greg,

28 grams seems to be a reasonable weight for a steel string bridge, I would think.

Some classical builders believe less is more, like Greg Smallman, for example. He now uses padauk exclusively to minimize bridge weight. Theory behind this is there is less mass on the top for the strings to have to excite and get moving. Other builders don't seem to pay nearly as much attention to bridge weight and it doesn't seem to affect the quality of their builds appreciably.

I think the internal damping qualities of the material selected is probably just as important as the weight of the bridge, within reason, of course. I have built guitars with padauk, cocobolo, and EIR bridges, and I would not be prepared to argue that they have played a highly significant role in the overall sound. Each guitar sounds good in its own way.

Best,

Michael

Author:  Sylvan [ Sat Oct 08, 2005 10:16 am ]
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I have recorded my bridge weight for some time. I have come to prefer
Brazilian Rosewood bridges simply because of the weight factor. My bridge
design in ebony is always approximately 30-34 grams. In Brazilian
Rosewood it is closer to 20 grams. I think the weight makes a huge
difference in tone with absolutely no loss in structural integrity. These
weights are without bridge pins or saddles.

Author:  McCollum [ Sat Oct 08, 2005 1:15 pm ]
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Well, I'm different than you guys in that I shoot for a 30-35g weight in my bridges. I've found that I can control the way a guitar sounds by altering the weight of the bridge, and I definitely won't use a light bridge on a cedar or redwood topped guitar again. A heavier bridge gets much more power and sustain out on these two tops. I think it also has something to do with my cedar tops not breaking up soundwise. To me, lighter bridges don't work well in my guitars. They seem to sound thin and reedy. And I'm known to have very loud guitars, so maybe the heavier aids in this result.

So I guess my theories are different from everybody elses, but what works for me may not work for someone else.

Lance

Author:  Alan Carruth [ Sat Oct 08, 2005 1:39 pm ]
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This is one of those things that you'll have to work out for yourself, to fit your system. I tend to find that steel string bridges in the 30 gram range work OK for me, but if 25 is too heavy on your guitar, then that's what works for you.

The important thing to remember is that the bridge is, in many ways, simply the heaviest brace on the top, if not the stiffest. It's how the whole system works tegether that counts. There are probably some rules of thumb that could be worked out, like whther you want to go with the light bridge on scalloped bracing or not, but I don't know what they are.

Author:  GregG [ Sat Oct 08, 2005 1:49 pm ]
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This is fascinating to me because I found out on my guitar(yes it was only #1)through trial and error that I lost volume, sustain, power, and tone by sanding only a few(maybe more) grams off of my bridge. Now I was also sanding and experimenting with other aspects of the guitar, but I'm fairly certain that the bridge work did most of the damage. The guitar still sounds wonderful, but it was a monster before I messed with it....I'm glad I did what I did though because I learned a ton with this one. I had constantly read that weight was a killer to a guitar, so I thought hey, I'll lighten everything....BAD idea in my mind anyway. How important is the saddle in all of this, I used a rather large one and was wondering if smaller equals better here?


The other question that I never asked was....how far do you extend your bridge? just to the outside edges of the X-brace, inside edge, short of that? This seems to be a critical area as well.

Thanks,
Greg

Author:  Michael McBroom [ Sat Oct 08, 2005 2:14 pm ]
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Lance,

Are your bridges longer than a typical bridge?

I build classicals, and have recently built a few 10-strings. One of the characteristics of a 10-string is noticeably greater sustain over a 6-string classical, and I have been thinking that at least some of this increased sustain is due to the longer bridge. True, it is also heavier, but the added length actually helps reinforce the top against the additional 60 lb. of string pull, thus my thinking it might be a contributor to the increased sustain.

Best,

Michael

Author:  BlueSpirit [ Sat Oct 08, 2005 3:23 pm ]
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Greg,
I've learned a ton of stuff from the men and women on this forum, but this one stands out the most to me.
"If you take wood off in multiple places, ie: bridge support and tone bars, or change the bridge support to a Maple and change the transverse bar, and build the guitar around these changes, what changed the tone? In your case from a monster, to what you have now. There's no way to tell. It could have been the bridge, but it just as well could have been the "sanding and experimenting with other aspects of the guitar" that did it.
John Mayes (he's a member here)has a good DVD on voicing that I would recommend. In it he explains a lot of the things that happen when even just a small amount of wood is taken off.
Hope this helps.

Author:  Paul Schulte [ Sat Oct 08, 2005 11:03 pm ]
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Greg I have always had the lower corners of the bridge(near the tail) intersect the center of the x-braces and the upper corners intersect the center of a finger brace.
I don't have any particular reason for doing this but it works for me.

Author:  Kevin Gallagher [ Sat Oct 08, 2005 11:47 pm ]
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   This is a point of infinite variability. Every bridge and its weight will have to be uniquely matched to the particular system of top wood, bracing, bridge plate material and weight/thickness and the body dimensions of the guitar it's being put on.

   You can't and shouldn't lock yourself into a set or default weight on your bridges. That kind of thing is for the big production houses. Their weights are ging to be more consistent simply because the environment in which they are mass produced is one that will yield that result.

   In a small shop, it's a point of more variability. We fabricate our bridges to fit a particular guitar so we have the luxury of shaping them according to a weight or mass goal. Even with a particular species of wood, the weight can vary widely from piece to piece so it's not even possible to specify a weight in that direction.

   Weigh the braces and top and bridge plate and then combine those weights and then go on to the weight of the bridge.

My opinion only,
Kevin Gallagher/Omega Guitars   

Author:  McCollum [ Sun Oct 09, 2005 2:48 pm ]
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I agree with what Al Carruth posted. You have to figure out your total package system -- what works for you and what doesn't. For example, I check the specific gravity in my braces and adjust those vs. how floppy or stiff the top is. I don't sand the top to a specific thickness. I flex the tops as I am running them through the thickness sander and when they hit a certain feel for the style of guitar I am building, I stop. (Although I am amazed at how consistent I am when I measure the tops afterwards.)

Michael: My bridges are six inches long and 1.75" at the deepest part of the belly. I shoot for just under 3/8" tall at the very front edge, but I also use thicker fingerboards than everyone else, just under 5/16" in the center. I like 3/16" saddle sticking out of the bridge and the same amount buried. So these are just some of the hopeful guidelines I go by - they don't always end up that way -- being that wood is wood.

Good Luck,

Lance

Author:  Sprockett [ Mon Oct 10, 2005 3:53 am ]
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Hmmmmm I don't even weigh my bridges, I have a standard shape that I use (1 for standard steel strings and one for fanned frets) and I find that adjusting the bracing and especially how I thin the edges has the single most impact on my sound.

May be time to do some tinkering, the best sounding guitar I have built to date (to my ears anyway) has a very heavy cocobolo bridge, Adirondack top and the bracing was a little thinner than normal and I spent time thinning the edges of the glued on top to get a good 'Bonk' tone out of it (more than usual on that one).

I think my bridges are around what McCollum is using, they are a little bigger than the normal bridge, I also use a wider saddle like Somogyi does so I need a little extra meat there.

Cheers

-Paul-

Author:  Brock Poling [ Mon Oct 10, 2005 4:30 am ]
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Paul brings up an interesting point in all of this though... how are you modifying the weight of your bridges? Are you hand making each one? If they are too heavy what do you do? Changing the geometry of them obviously is not the way to go....

Do you just reject them and make another?

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