uncle.fogey - Posted - 04/15/2012:  15:03:28

The relationship between the rim and the tone ring is very important, and it’s difficult to separate the two because they act together as a unit.



The simplest pot design is one with no tone ring at all, just a beveled top edge, as in a drum. These are also the lightest weight ones, normally.



The next step in sophistication would be to add a brass ring at the top which the head crosses over - this adds a little weight and changes the sound.  Banjos have been made like this for more than a hundred years - sometimes with a thin spun skirt. The Vega “Little Wonder” is one  example.  Here’s an old rim with a ring and spun skirt - this has a one-piece steamed rim with a scarf joint, and the rim is barely 3/8” thick:



This would make a great - sounding banjo for old-time music, I think. The tone ring is balanced with the rim and it’s simple.



History - sorry.



In the “golden age” of banjo design in the early 1900s, everyone was trying to come up with a better design than the next guy  - there was a lot of innovation, and manufacturers respected each other’s designs and tried not to copy each other.

Gibson and Vega were two particularly innovative companies, and strong competitors, I think.



Gibson came up with the idea of using a tube rather than a solid hoop, and in order to let it ring, they elevated it above the rim with ball-bearings:





This was then developed into a much more elaborate design, where a bigger ring was supported by ball bearings pushed upwards by springs - possibly the most elaborate banjo construction ever done - It was called the “Mastertone”.



In order to accomodate the holes and springs, a very wide rim was needed.  The maple rims made during this period were especially well-made, and, unfortunately, this high level of rim building crafsmanship did not continue into the 30s.



Vega felt that this design was an infringement on their newly popular “Tu-Ba-Phone” design, and they challenged Gibson, who acquiesced and abandoned the hollow tube design and invented the cast bronze tone ring - the “arch top”, which was a take off of the Ball bearing design, although much simpler - this led to the 3/4” rim, required by 3/4” tone rings which had to sit on the rim.

Once you cast something in bronze, you are stuck with it - it is “cast in bronze” - like "carved in stone", so from this point forward into eternity, ALL Gibson banjos had to have the tone ring be 3/4” wide - the tension hoops, with their 4-string string space, and flanges were dependent on that.  Gibson became the “cast in bronze” company, although that did not hurt them, because Earl Scruggs bought one, and the rest is history.



Vega continued to fabricate everything, which gave them a little more flexibility, but at the cost of efficiency. - Vegas were all over the map - 11”, 10 15/16” , 10 7/8"  rims, you name it.  Every Vega is a “custom model”- not a bad thing at all. - They are great banjos with a soul born of handcraft.  They had a special design for everyone (just like I do ha ha)

Other companies made spun-brass parts- Here’s a Bacon “Silver Bell model with a spun tone ring:



It was the era of great innovation in banjo design.

I have to point out that all this investment in banjo development was NOT done to attract 5-string banjo players - Most 5 string banjo players couldn’t afford these snazzy instruments - it was because of jazz and popular bands.  5 string banjo players benefited from the fact that these companies were trying to sell banjos to professional jazz players.  The date of Earl Scruggs’ birth, 1924, was also the first 5-string banjo EVER made by Gibson.



In terms of the project, generally speaking, banjos used for bluegrass are heavier than those used for clawhammer and old time music.  The model I have described, established by Gibson in the late 1920s is a heavy wood rim with a heavy cast copper alloy tone ring which sits flat on the top of the wooden rim.

Here is a photo of various tone rings and their respective weights:





Here is a drawing (in scale) of a 1927 Gibson and a 1925 Vega Tu-Ba-Phone.



These are in scale!! you can see how much more massive the Gibson model is compared to the Vega model.

NONETHELESS - I repeat - nonetheless, the Tu-Ba Phone is just as loud as the Mastertone, even without the resonator ( I have sound files, but cannot figure out how to attach them on this post) I'll do it later if anyone is interested

Later ones had the rim thickness at the bottom reduced because of the ”one piece” flange, which served the same purpose as the 49-piece assembly of the Vega bracket band - you can see how Gibson was using “value engineering” to refine their products.

Here is a drawing of the later Mastertone and several later Vega.

NOTE how the Vega rims are cut back to cantilever the tone ring - This is an important element I want to explore in this project.





SO this brings me to my own designs, which are the subject of this long thread.  I am not casting, spinning, or fabricating (in the Vega mold).

My tone rings are brazed together, and the brazing creates stresses that I think  enhance the sound.

My rims are 5/8” - which seem to me to be balanced with the weight of my tone rings

I am trying to find a nice relationship between the tone ring and the rim, and do something that hasn’t been done before - EVERYTHING has been done before, but I’m doing my best -We’ll see how it goes.

Grum - Posted - 04/15/2012:  16:06:13

Fantastic article. I'm keen to read the next installment but I'm sure people would appreciate a PDF of the whole thing when you're finished.

So far you've not mentioned Stelling's contribution or the various ways wooden tone rings are done. Hopkins, Bellbird ans others are having great success with wooden tone rings with plenty of volume and tone without the weight.

uncle.fogey - Posted - 04/15/2012:  16:29:50

I am showing historical stuff because it's very interesting, and if you don't pay attention to history, you're bound to repeat it. PLUS, showing what was done before provides precedent to my logic, but what this project is really all about is building a new banjo that is NOT like  Gibson, Vega or Stelling.

Granted, it would have been interesting to mention Stelling's wedge fit idea,even though has nothing whatsoever to do with this project.  Thinking about it, however, I probably should have shown a picture of it.

Thanks for the thought - I will add it to the final draft.

Bill H - Posted - 04/15/2012:  16:46:12

Interesting info. Great graphics. 

Dave1climber - Posted - 04/15/2012:  18:37:10

Thanks for the history, and your insight about how it relates to your design.

Do you have any additional thoughts about the Gibson "ball bearing" tone ring?

Dave

aeroweenie - Posted - 04/15/2012:  20:01:39

Thanks for the history lesson, very interesting.  Does the shape of the edge of the rim have much effect on tone?  I see your wood tone ring is similar to a flat head ring.  I made a rim out of a maple drum shell and just radiused the edge of the rim.  It didn't sound very good, maybe because the shell had about a million plys, even though it was only .25" thick.

5stringpicker2 - Posted - 04/15/2012:  20:50:33

Loved it! Keep on with the History lessons. You're never to old to learn. :)

( I  )====='----<::)

uncle.fogey - Posted - 04/16/2012:  05:40:54

quote:

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Originally posted by Dave1climber

Thanks for the history, and your insight about how it relates to your design.

Do you have any additional thoughts about the Gibson "ball bearing" tone ring?

Dave

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There were 2 different versions of the BB pot. The first one, which is the one I show the drawing of, had holes in the outer brass band, which was spaced out from the wood rim . The later version had a thicker brass band that was closer to the wood rim.

From what I'm told, the earlier version, with the holes sounded better.  Of course, we know, holes are an important element of banjo aesthetics, if not sound.

The guy who taught me a lot about how to play and build banjos in the 60s, Winnie Winston, had a ball bearing Granada, with which he won a lot of contests and made recordings.  It was the earlier kind with the holes.

Here are a few links to his website pages, and there are sound files where you can hear some decent recordings of that BB Granada.

julianwinston.com/music/my_gra...banjo.php



julianwinston.com/music/me_and...anjo2.php

uncle.fogey - Posted - 04/16/2012:  06:01:10

quote:

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Originally posted by aeroweenie

Thanks for the history lesson, very interesting.  Does the shape of the edge of the rim have much effect on tone?  I see your wood tone ring is similar to a flat head ring.  I made a rim out of a maple drum shell and just radiused the edge of the rim.  It didn't sound very good, maybe because the shell had about a million plys, even though it was only .25" thick.

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Normally, the bearing where the head goes over the edge of the rim is 1/4" diameter - at least that's the standard.

a rim that's only 1/4" thick is probably really lightweight, and that could be the reason you didn't like the sound, rather than the radius or number of plies.

The conical shape with a radius at the top edge is the simplest way to taper the top of a thick rim. The Gibson flathead ring shape is an easy shape to cast and machine, which is why they went in that direction after the archtop. There were a couple of interim stages, like the "pyramid". The final configuration is about as simple as you can get, and variations in weight are possible by how much material is hogged out of the bottom.

My "woodie" extends in to the pot beyond the inner edge of the rim to give it a little more mass - the rim, while 1/2" thick. is very lightweight chestnut:

Dave1climber - Posted - 04/16/2012:  07:27:21

Ken

Thanks for the links.  Winnie Winston, an interesting man, one could wish to have known him, but if wishes were horses, beggars would ride.

Dave

bordertownbrown - Posted - 04/16/2012:  08:39:54

Great work Ken, can't wait to own a copy of the book when it goes to print!

stigandr5 - Posted - 04/16/2012:  08:58:18

What do expect the effect of the cantilevering of the Tubaphone ring to be?

Also, do Whyte Ladie and Electric tonerings fall into the BB category (ring suspended on points)?

I love watching this thing develop.

Jonnycake White - Posted - 04/16/2012:  09:04:53

Great stuff, Ken.  I'm starting to thing seriously about my next serious banjo build, and this is certainly feeding my thoughts.

uncle.fogey - Posted - 04/16/2012:  10:18:57

quote:

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Originally posted by stigandr5

What do expect the effect of the cantilevering of the Tubaphone ring to be?



Also, do Whyte Ladie and Electric tonerings fall into the BB category (ring suspended on points)?



I love watching this thing develop.

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I "think" the catilevering was intended to allow the tonering to vibrate and ring more.  They kept fooling with the size of the gap over the years, and never abandoned it, even during the Martin era, so there was a definite reason and logic for them doing it.  Of course, you can get a screwdriver blade in there to pry off the tone ring, so it serves that function as well.

Numerous banjo designs over the years have featured some sort of a "floating the tonering" component - as you say, the WL, and the BB. The Electric went the other way but also had "points".  Some of the spun tone rings extend into the pot unsupported, like a bell.  Maybe it does nothing, but it's a detail that has been used many times in different forms, like holes in the tonering.

Gibson's cast designs have the tone ring sitting flat on the top of the rim.  I once lifted the archtop ring of my Granada 1/16 off the rim a'la the tubaphone cutaway with a wooden shim, and it sounded awful.  Some people cut away the corner on the upper inside of the rim on Gibson flatheads to allow the tone ring to hang out.  This, I think is called a "tone-bell", and many people like it .

All the pots I design and make have tone rings that are unsupported by the inside of the rim, and I like the way they sound, but I'm not trying to make my banjos sound like some other banjo that's "out there".

When I finish my prototype, I am going to try a heavy Gibson type Flathead ring on it, tone bell fashion, as a test and comparison - just to see what happens.

uncle.fogey - Posted - 04/16/2012:  14:35:01

In a previous post, I alluded to the fact that a tubaphone is just as loud as a much heavier PW Granada.  Interestingly, they sound very similar - it has something to do with the mass and vibrating head diameter.  A flathead would sound different, not as loud - I can't explain it.

Anyway - tubaphone and a PW arctop:

sound comparison

sound comparison

Emiel - Posted - 04/17/2012:  05:06:57

quote:

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Originally posted by uncle.fogey

In a previous post, I alluded to the fact that a tubaphone is just as loud as a much heavier PW Granada.  Interestingly, they sound very similar - it has something to do with the mass and vibrating head diameter.  A flathead would sound different, not as loud - I can't explain it.

Anyway - tubaphone and a PW arctop:

 

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Is that Tubaphone openback or is it a resonator banjo?

Waltj - Posted - 04/17/2012:  05:49:19

Thanks for the great information. It is appreciated.

Walt