Ken LeVan - Posted - 07/26/2012:  15:12:44

I am going into this subject now, because I have to make bridges to set up these two banjos, so I am at that point in the process.



There is probably no single part of a banjo that has a greater effect on the sound than the bridge, and the cost-to benefit relationship  of a good bridge is unequaled.

 There are a number of great bridge builders on the Hangout, so there is no good reason to buy a generic bridge “off the shelf”.  Contact one of the builders on the hangout, and they will build a good bridge for you.  Several of them sell their bridges through familiar banjo supply  sources.



 I have been making bridges for 50 years, and during that time have never bought a bridge.  I am not attempting to suggest that my method of making them is the best way.  This is  just the way I make them , and I will show that way and explain my logic.

In the 60s I made bridges by just copying the Grover ones and whatever else was around - they were too heavy. I lightened them by carving material away and drilling them out, and that worked fairly well. 

When my son started playing the cello, I had a friend, who was an orchestra conductor (still is).  He had worked his way through the Eastman School repairing and setting up violins, violas, and cellos.  He taught me how to make cello bridges, and that became the basis of the logic for my bridge making.



I think that a lot of bridge builders make them similarly, although the shapes and the feet are different - to each his or her own.



DESIGN:

The reason they call a banjo bridge a “bridge” is because it works like a traditional bridge, and is the “bridge between the strings and the rest of the instrument.  They come in many shapes.



Just as in a bridge you would walk or drive over, the weight on top of the bridge follows a ”load path” to the ground. Architects and enginners over the centuries have refined this to make it more direct.

One of the earliest designs was the “post and lintel”, and I am including a picture of a “post-and-lintel” bridge that I actually made to try it out - it was not a great bridge:





Later on, the “arch” was developed, which directed the load path to the ground in a more direct way.



This is the approach I have taken, imagining the structural load path of a conventional bridge to be similar to the path vibrations would travel from the strings of a banjo to the head with a banjo bridge - a different kind of load:

The bridges I make follow this design logic.





WOOD:

As with any acoustical stringed instrument, the wood it is made from is very important.

I prefer red maple, but I have made bridges from red maple, sugar maple, so called “submerged maple” of unknown species, walnut, cherry, amelanchier, ash, hickory, black locust, ebony, rosewood, purpleheart and brass (probably others I have forgotten)



Regardless of the species, logs are sawn in a certain way, and yield boards with different grain orientations.

Here’s a section of a maple log showing some of the ways they are cut up:



Most of the boards are “flat cut, and this is what you generally get in a lumber yard:



The flat cut boards are good for laminated necks by cutting the neck halves out and opposing the grain:



The quarter cut section is what we are interested for bridges:







I squirrel away boards that are good for bridges, and have a collection of them in the shop.  Leftover pieces from neck boards are often perfect





I have a page of patterns of different heights, made on the computer. I use those to make templates.

Then I trace off a bunch of blanks and cut them out with a bandsaw:



After that I roughly sand them down and glue rosewood or ebony saddle strips onto the top with CA



Then I sand them more and trace the outline of the bridge onto each one, drill the holes and rough shape them with a bandsaw. After that, I clean up the arches and feet with a small spindle sander on the drill press:



Now I have a lot of slightly oversised blanks, which I will go no further with until it’s time to fit an actual bridge.



Here’s the basic blank - the maker’s name always faces the neck:

I am imagining that this will precipitate questions. I may have to re-post sound files, which is no problem.

Please feel free.

Ken

Spitfire-Smith - Posted - 07/26/2012:  19:38:33

A ton of great info Ken. As Always!

rudy - Posted - 07/26/2012:  19:43:19

Most excellent, Monsour Ken!

skollie - Posted - 07/26/2012:  23:08:06

HI KEN LOOKS AMAZING ,WOULD YOU SEND ONE TO SOUTH AFRICA .

DerekWest - Posted - 07/27/2012:  06:01:11

Thanks for all the info! I really appreciate the log analysis.
-DW

Dave1climber - Posted - 07/27/2012:  14:50:55

Ken

Do you shape them all to the same radius?  What about "compensation"?  Great pics and information as always.

Thanks

Dave

dougtape - Posted - 07/27/2012:  14:59:40

so, do you sell just your bridges?

Ken LeVan - Posted - 07/27/2012:  15:07:35

quote:

---

Originally posted by Dave1climber

Ken

Do you shape them all to the same radius?  What about "compensation"?  Great pics and information as always.

Thanks

Dave

---

Dave,

Over the years I have tightened the radius quite a bit. I started with a 7" radius, and now have a 4 1/2" radius. Obviously, the smaller the radius, the more the compensation.

4 1/2" seems to work very well - they are not truly "compensated" bridges, but they get you into a good place, and they smile at you .

Ken

TxScout - Posted - 07/27/2012:  15:50:06

What bridge would you use for a fretless?

Thanks,

Don

Edited by - TxScout on 07/27/2012 15:50:51

Ken LeVan - Posted - 07/27/2012:  17:23:17

quote:

---

Originally posted by TxScout

What bridge would you use for a fretless?

Thanks,

Don

---

There wouldn't be any point to using a moon bridge on a fretless, so I'd use a straight version, but I'd keep the camber.

aeroweenie - Posted - 07/28/2012:  20:04:45

Great info, especially about the wood grain and the different types of cuts.  Thanks!

Spitfire-Smith - Posted - 09/07/2012:  11:50:08

Once again, more great info! Any timelines on when your book might be released?

Ken LeVan - Posted - 09/07/2012:  13:41:47

I am just finishing the last thread on this "Building a Banjo" series, and will actually lay out the book over the winter.  There will be a lot of stuff in there that I haven't posted on these threads.

I am hoping I can get it done by spring - it keeps getting bigger and bigger.

Hang in there,

Ken

Spitfire-Smith - Posted - 09/07/2012:  14:12:02

Very cool. Looking forward it!

Dan Drabek - Posted - 09/07/2012:  14:40:44

That's about the best bridge building tutorial I've seen. For many years I've used a standard Grover compensated bridge. It loses a bit of sharpness and volume compared to a straight bridge, but I can't stand poor intonation when playing up the neck, so it's a fair tradeoff for me. How would you expect the curved design to compare with the stepped Grover?

DD

wuzapicker - Posted - 09/07/2012:  15:00:16

Ken,

I know patience is a virtue - actually, the fruit of the Spirit (Gal.5:22) - so I shall await publication of your book with patience. It will surely be like no other done before.

Michael

slou92 - Posted - 09/07/2012:  15:14:02

Ken, how did you like cherry for a bridge? I'm working one now and am curious to how it's going to turn out. Also, do you aim for a certain weight or just go by sound?

Ken LeVan - Posted - 09/07/2012:  16:46:24

quote:

---

Originally posted by Dan Drabek

That's about the best bridge building tutorial I've seen. For many years I've used a standard Grover compensated bridge. It loses a bit of sharpness and volume compared to a straight bridge, but I can't stand poor intonation when playing up the neck, so it's a fair tradeoff for me. How would you expect the curved design to compare with the stepped Grover?



DD

---

I like it very much - it's simpler than the Grover, and a LOT easier to adjust the weight by thinning it down.

Ken

Ken LeVan - Posted - 09/07/2012:  16:58:15

quote:

---

Originally posted by slou92



Ken, how did you like cherry for a bridge? I'm working one now and am curious to how it's going to turn out. Also, do you aim for a certain weight or just go by sound?

---

I thought the cherry was not as bright as the maple and could not produce as "complex" a sound. It was "mellower", but my feeling is that you could do that with a looser head.  I have had better success with beech bridges than cherry.

I do not weigh every one, but I am careful about the thickness and I am really familiar with the pieces of wood I use - I don't make large quantities of these.

Obviously, an 11/16" bridge will weight more than a 5/8" one, and the higher ones are a little wider at the feet, so they weigh a little more.  If one sounds "sluggish" I will thin it down, and if that doesn't work, I will just chuck it.

Dan Drabek - Posted - 09/07/2012:  17:21:42

It doesn't surprise me that bridges generally trend toward maple. It's been the material of choice on violin bridges for hundreds of years. I once made one of osage orange, and was disappointed with the result. I also made one of brass, and was horrified with the result.
Have you ever topped a bridge with bone, rather than ebony? It's something I've considered trying, but have never gotten around to it. Seems like it would wear well, if nothing else.

DD

Ho C Ying - Posted - 09/07/2012:  18:44:09

Cool!

cmymarvin1973 - Posted - 09/07/2012:  19:44:30

My first post....and I reply to a Banjo Bridge Tutorial??!!  Great stuff, makes me want to head out to the shop and salvage some scrap wood. If you have a book coming out, I will sure be interested. Thanks for the info.

BNJOMAKR - Posted - 09/08/2012:  04:23:29

As always, great work and detailed info. Thanks, Ken!

Marvin

Ken LeVan - Posted - 09/08/2012:  05:51:44

quote:

---

Originally posted by Dan Drabek

It doesn't surprise me that bridges generally trend toward maple. It's been the material of choice on violin bridges for hundreds of years. I once made one of osage orange, and was disappointed with the result. I also made one of brass, and was horrified with the result.

Have you ever topped a bridge with bone, rather than ebony? It's something I've considered trying, but have never gotten around to it. Seems like it would wear well, if nothing else.



DD

---

Funny you should mention brass. I actually made a brass bridge a long time ago for a guy with a Paramount. It was AWFUL, and had so much sustain it made the banjo sound like a Dobro, or something strange.

I have never tried Osage orange, but I have tried Black locust, which is similar. It had a harsh metallic sound, which some people out there might like, but I didn't.

I have never tried a bone saddle. Corian might work for that.  Without ever having tried it, my fear would be that bone or some kind of synthetic material might damp vibrations, although they use it on guitars.

jay_m - Posted - 09/08/2012:  06:05:13

as usual, an excellent tutorial.

making bridges is a comparatively easy with just a few tools, and its really something everyone should try. the variety of sounds that can be produced with different materials is astounding, and the fact is that with a little patience, you can very deliberate hone in on whatever specific sound you are hoping to get in a banjo by experimenting with and comparing different bridge materials and designs.

Dan Drabek - Posted - 09/08/2012:  09:06:19

quote:

---

Originally posted by uncle.fogey

Funny you should mention brass. I actually made a brass bridge a long time ago for a guy with a Paramount. It was AWFUL, and had so much sustain it made the banjo sound like a Dobro, or something strange.

I have never tried Osage orange, but I have tried Black locust, which is similar. It had a harsh metallic sound, which some people out there might like, but I didn't.

 

I had exactly the same result with my brass bridge. I likened the sound to a cross between a National guitar and a sitar.  :->

I've worked with both osage and black locust and you are right--they're nearly the same except for the color. And osage is a bit springier. But my experience with osage as a bridge was also very similar to yours with the locust. 

It's nice to know that the experiments were consistent.

DD

Roll Player - Posted - 09/08/2012:  09:52:16

I've played a few bridges with bone toppings. About twenty years ago, a fiddler friend of mine built one with a cherry base, based on a design I made. The frame was sorta similar to the Kateyez design of today and the bone was only about 1/16" high, rather than the usual 1/8" to keep the thing from being too heavy. It's a good sounding bridge with a bit more sustain than most.

A few years after that, I had a bridge that I had made too light, having filed away a lot of wood from the openings and making the edges round like a Hotspot I had. I got the idea of sawing off the ebony cap and gluing on a bone top, also about 1/16" high. It restored some low end to the bridge and I used it on my ESS for a number of years until it finally started sagging too much in the middle. One time, I was in a jam in Glenrose Texas with Ben Greene, who was playing with James King at the time and came out after the shows were over with a couple of other guys from the band. He played my banjo for quite a while and kept looking at the bridge, saying, "That shouldn't work, but it does." He liked my banjo a lot, bridge and all, and it sure was a pleasure listening to him pick it.

A few days ago, I was over at Jerry Rabun's (aka xnavyguy's) house and he had a bone capped bridge on a banjo with a Helix-style rim he built. The base wood of the bridge was mesquite. I thought it really brought the banjo to life, with a nice clear sound. Once again, the cap was only about 1/16" high, and the overall weight about 2.1 grams. I think that's the key to using bone for a cap. Higher caps with bone, like the standard 1/8", add too much mass and cause some muting.

Edited by - Roll Player on 09/08/2012 09:58:31

Dan Drabek - Posted - 09/08/2012:  11:00:42

That's interesting stuff. Sounds like it might be worth experimenting with. You could probably shave off half the ebony and leave a nice black inline. Ivory might be a good compromise, as it's just a bit softer than bone. An old piano key would top a lot of bridges.

DD

Roll Player - Posted - 09/08/2012:  13:43:37

I made a few more where I sawed off the ebony and glued on a bone cap, but the one I had on the Scruggs was the best one. Leaving a bit of ebony would probably look cool, but only add unnecessary extra weight and another barrier between materials for the sound to cross.

I also made one with a higher (1/8") bone cap, but to reduce the weight I scalloped the area between each slot. It worked pretty well and looked cool, but I have CDD (Craftsmanship Deficit Disorder) and the cap kept coming off and needing to be re-glued.

I never thought of trying ivory.

Art

Roll Player - Posted - 09/08/2012:  13:50:15

Here's how the Bone over Mesquite bridge looks. This is the one Jerry built. Unlike me, he doesn't have CDD.

I think he shaved some bone off the top since taking this picture. Of course it also has string slots now, too.

Edited by - Roll Player on 09/08/2012 13:52:26