Why Coprion?

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ttf_Pteranabone
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Why Coprion?

Post by ttf_Pteranabone »

Why did Conn experiment with Coprion design?  Why was it less than successful?  (Sam Burris likened it to your crazy uncle off his meds, or something along those lines.  DJ likened it to wrapping a 6H in duct tape).
ttf_BGuttman
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Why Coprion?

Post by ttf_BGuttman »

Coprion is an electroformed bell.  It is created by plating in a tank.  It comes up fully formed and needs almost no working to get it into shape.  It was thought this might provide a better type of resonance.  It certainly reduces the  labor -- you don't have to beat a flat sheet of brass into a bell shape.

Coprion is pure copper.  You can't plate an alloy like brass easily.

Personally I like the look of it.  Kinda snazzy.

After all, we like solid sterling silver bells also, don't we?

But Coprion never caught on with the pros.  So it's defunct.

ttf_donn
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Why Coprion?

Post by ttf_donn »

Just to put in a word about Reynolds' Bronz-o-lyte - the bass trombone version of which is more or less copper.

Unlike the tenor trombones and other instruments that maybe had bells of bronze as the word is commonly understood.  Maybe someone has put one under XRF to see if there's any tin in the mix, but it's as red as it could be.

I don't have anything of value to report about it, beyond that the Reynolds bass trombones have big copper bells and seem to play OK.
ttf_timothy42b
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Why Coprion?

Post by ttf_timothy42b »

Wildly speculating.

Electroforming would allow making bells without a highly skilled artisan spinning them by hand, and they should all come out relatively the same.  (I'm not sure what the tolerances are - I'm sure less than CAD/CAM, but maybe tighter than hand work)

It seems to me there would be some negatives too.  Copper doesn't heat treat, precipitation hardening is not available either for pure or even for the alloys.  The only way to harden it would be work hardening.  So electroforming would leave it very soft, like after a good annealing, and that might be too soft to survive.  If you have to do a final spinning to work harden it, then you've lost your advantage of not needing skilled labor. 

I imagine the equipment is much more expensive than a lathe, and probably produces large amounts of hazardous waste, too. 
ttf_harrison.t.reed
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Why Coprion?

Post by ttf_harrison.t.reed »

Also going off what Tim said, if you just electroformed a bell and didn't work harden or heat treat it, or buff it, you'd have a uniform thickness and uniform hardness bell. That's pretty lame.

From what I've heard, the coprion trumpets were much more popular.
ttf_Matt K
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Why Coprion?

Post by ttf_Matt K »

THe answer is another question in and of it self: "Why not?" They tried all sorts of stuff we might think retrospectively are a little crazy!  That said, trumpet players still use them today to some degree; Schilke makes them under the name 'Beryllium Bronze' (http://dallasmusic.org/schilke/Bells,%20slides%20and%20finish.html).  If you search Dillon you can place an order for a few models of them. 

One characteristic not yet mentioned is the lack of a seam.  Trombone bells generally are two piece with a seam towards the flare.  Bach bells (and the 'copies' or 'inspirations') are typically one piece with a seam going down the length of the bell.  Electroform bells are seamless.  Its hard to compare the bells for just this characteristic alone but there are differences between the one piece, two piece, and I'd imagine with the seamless.  Evidently trombone manufacturers have either decided this difference isn't something people would generally want or that the cost to get the proper tooling of that size is prohibitive.   Though Rath does offer "bronze" parts, I don't know what the actual makeup is of the material, nor do I believe they are electroformed.  (What we as trombonists call 'red brass' ,90% copper - 10% zinc, is often referred to by other people as bronze in some cases. So he might just be going with the conventional indication.)
ttf_Euphanasia
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Why Coprion?

Post by ttf_Euphanasia »

I'm not sure what Conn was after when they made these bells. Their literature is hogwash. They day the sound doesn't break up at high volumes. Anyone I know who has played Coprion trombones will tell you that yes, it does--quite suddenly and forcefully.

What they didn't address, and the reason I like Coprion bells, is feedback to the player. They're very lively. I find that I'm more involved in what I'm playing when I get that kind of feedback. They're the opposite of a P-Bone.

Quote from: harrison.t.reed on Aug 12, 2017, 06:37AMAlso going off what Tim said, if you just electroformed a bell and didn't work harden or heat treat it, or buff it, you'd have a uniform thickness and uniform hardness bell. That's pretty lame.
 Image

I don't see why this would be a problem. I don't think any manufacturer actually works with varying thicknesses of metal to enhance the sound--not even a Bach "Stradivarius."  Image  Differing thicknesses and hardnesses are a by-product of manufacturing techniques. Some designs--notably one-piece bells--are bound to be asymmetrical in both hardness and thickness because of the amount of stretching that occurs.

ttf_harrison.t.reed
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Why Coprion?

Post by ttf_harrison.t.reed »

Quote from: Euphanasia on Aug 12, 2017, 07:23AM
 Image

I don't see why this would be a problem. I don't think any manufacturer actually works with varying thicknesses of metal to enhance the sound--not even a Bach "Stradivarius."  Image  Differing thicknesses and hardnesses are a by-product of manufacturing techniques. Some designs--notably one-piece bells--are bound to be asymmetrical in both hardness and thickness because of the amount of stretching that occurs.


Only because you used the  Image emoji:

You can think whatever you want. Some people think that we never walked on the moon. But I don't peg you as the tin foil hat type. No way.

Manufacturers do in fact work with varying the thickness and hardness throughout the length of their bells. Sometimes it's unintentional, but for manufacturers today it's intentional, and usually done to get closer to what the buffers at Elkhart were doing in the 40s and 50s and 60s.

Shires does the T7 treatment:

T7: Treatment 7—thinner in the flare—this provides easier response and lighter, less centered sound than the standard bell treatment

Edwards heat treats and work hardens bells as an option, but also has:

CF treating is a partial heat treating process. This treatment allows the bell to blow more freely and adds colour to the sound.

Double buffing thins the bell slightly. It actually creates a thickness in between any two gauges.

And the 396-A bell is treated so that it is not uniform.

Noah Gladstone's vintage orchestral trombone varies the thickness of the bell:

Two piece bell construction using a "cross braze" similar to pre WWII Conn bell construction.
- Bell stem is constructed from very thin gold brass, the flare is made from yellow brass with a thin rim wire which is soldered

And we all have heard that the way the old bells coming out of Elkhart were made was special. The guys buffing the bells were changing the thickness and varying it in different parts of the bell. That's why manufacturers are doing the same thing today.

so  Image right back at ya.  Image

I only mentioned what you were referring to before because it does seem like having a bell that's thinner in some spots than others is desireable. You try a Shires red bell, and then you try the T7 Elkhart bell, and 9/10 you fall for the T7. I dunno. A bell that has the exact same thickness and hardness throughout the entire length seems like it would be no fun, unless it was just thin to begin with.
ttf_Euphanasia
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Why Coprion?

Post by ttf_Euphanasia »

Quote from: harrison.t.reed on Aug 12, 2017, 07:49AMOnly because you used the  Image emoji:
Right, because I don't see how "lame" defines a practice that's used by every manufacturer with the exception of a few modern boutique builders. So yes, I was unaware that Shires was offering different thicknesses and Edwards was offering work-hardening as an option, but aside from a very few examples, it would seem that manufacturers keep the metal in the thickness it ends up in when it's formed into the shape of a trombone.



Quote from: harrison.t.reed on Aug 12, 2017, 07:49AM
And we all have heard that the way the old bells coming out of Elkhart were made was special. The guys buffing the bells were changing the thickness and varying it in different parts of the bell. That's why manufacturers are doing the same thing today.

so  Image right back at ya.  Image
Again, I don't think this was intentional. I think they were buffing out areas that had been brazed and needed to have material removed so that they would be smooth again. And I had no idea that  Image was an insult. It wasn't intended as such. I didn't understand how you drew the conclusions you did. I still don't.

Quote from: harrison.t.reed on Aug 12, 2017, 07:49AM A bell that has the exact same thickness and hardness throughout the entire length seems like it would be no fun, unless it was just thin to begin with.
"Fun" is what I like about the Coprion bells. They feel good when you play them. However, since most of them were used on 18H student horns, I don't think Conn was going to any great lengths to thin or anneal specific parts of the bells. It's hard to say, since so many of them ended up in the public school system where they were beaten on until they had different dimensions and hardness than original.

ttf_harrison.t.reed
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Why Coprion?

Post by ttf_harrison.t.reed »

Euphanasia, I had to just send that emoji guy back at ya, I'm not too much worried about it beyond that. You got me wishing I could try a copper bell now.

That is a bummer about them only being used on student trombones.

It seems like the Coprion was a way of mass producing larger bells, then. It certainly seemed to be touted as a premium option for trumpets though. I have actually heard a coprion trumpet, but not a trombone.

A side question, didn't Yamaha electro form its bells?

as for the boutique vs elkhart, and whether or not the burnishings and buffings were cosmetic or intentionally done  ... I don't know. For Edwards and Shires and Rath (see below), it is intentional, and likely because they really tried hard to deconstruct what made a great trombone great, and then do an even better job.

I have a feeling Conn and it's staff knew exactly what they were doing in the 30s through the 60s. When you're buffing out the area where you've connected the flare to the stem (or whatever kind of bell you're working on) and accidentally overdo it, but then put it on a horn anyways, you'd notice pretty fast that your mistake was a stroke of genius, even if you don't know why, and unfortunately even if you don't write it down or tell your replacement in abilene what your trick was.

Rath on its bells:

All Michael Rath bells are constructed in two pieces, a flare and a spout, allowing us to select the most appropriate gauge (or material thickness) for the bell flare and spout independently. They are produced entirely by hand in our workshop and are finished in clear lacquer as standard, although various other finishes are available.
ttf_BGuttman
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Why Coprion?

Post by ttf_BGuttman »

There were pro horns made with Coprion.  Problem is the mandrels only worked for the smaller bores.  So there is a 10H that is a 6H with a Coprion bell, and a 12H that is a 4H with a Coprion bell.  I also saw a seventy-something with a coprion bell.

Never saw a larger horn with Coprion though.
ttf_harrison.t.reed
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Why Coprion?

Post by ttf_harrison.t.reed »

How does it compare to a silversonic? I can't overblow my silversonic,  but besides that little feature, I imagine it would feel and sound similar to silver?
ttf_blast
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Why Coprion?

Post by ttf_blast »

I have a Rath R9 with a copper bell. Mick offered that in the early days. I like it a lot. Not at all like silver. Very warm at low dynamics and gets interesting when louder. Great feedback to the player.

Chris Stearn
ttf_BGuttman
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Why Coprion?

Post by ttf_BGuttman »

Quote from: blast on Aug 12, 2017, 12:41PMI have a Rath R9 with a copper bell. Mick offered that in the early days. I like it a lot. Not at all like silver. Very warm at low dynamics and gets interesting when louder. Great feedback to the player.

Chris Stearn

... But that was made from sheet copper.  I don't think Mick had access to any electroforming equipment.  The difference would be the amount of work hardening the copper endured.

Still, all copper is VERY different from either Sterling Silver or pure Silver (SGX).
ttf_blast
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Why Coprion?

Post by ttf_blast »

Quote from: BGuttman on Aug 12, 2017, 02:20PM... But that was made from sheet copper.  I don't think Mick had access to any electroforming equipment.  The difference would be the amount of work hardening the copper endured.

Still, all copper is VERY different from either Sterling Silver or pure Silver (SGX).

It was indeed formed from sheet..... by a forum member.... these bells are still very soft, though not electro formed. I was answering a question from Harrison about comparing sounds.

Chris Stearn
ttf_Rockymountaintrombone
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Why Coprion?

Post by ttf_Rockymountaintrombone »

Just was surfing eBay - there's a beautiful 1957 Conn 10H with the coprion bell (same horn as the 6H except for the bell material) for sale there.

Looks to be in great condition - just thought I'd pass the info along since people are talking about these horns.

Jim Scott
ttf_BillO
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Why Coprion?

Post by ttf_BillO »

Quote from: harrison.t.reed on Aug 12, 2017, 06:37AMAlso going off what Tim said, if you just electroformed a bell and didn't work harden or heat treat it, or buff it, you'd have a uniform thickness and uniform hardness bell. That's pretty lame.

From what I've heard, the coprion trumpets were much more popular.
Not so sure about all this.

In electroplating/forming, you can very accurately control the deposition rate and uniformity.  This leads me to 2 possible conclusions.

1) The thickness could very well be much more uniform that a hammered and spun bell.  If anyone has access to one of these bells it might be interesting to put this to the test.

2) If the deposition rate was consistent and slow enough, the copper would tend to form in it's crystalline structure (face centered cubic) and might be harder than normal un-worked copper.

Now, I'm not saying this is what Conn did, but these are possibilities.
ttf_The Sheriff
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Why Coprion?

Post by ttf_The Sheriff »

From the Anderson silverplating website:

Anderson plating offers electro formed bells for trumpet, cornet, and trombone. Besides being consistent, these bells have controlled distribution of metal. The throat and flare are made thin for excellent response and projection, and the stems are left heavy to give strength at the braces and to facilitate bending.

A few years back I picked up one of their electro formed copper trombone bells for a project I was doing. The project never got off the ground so it has been a planter ever since.
ttf_BGuttman
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Why Coprion?

Post by ttf_BGuttman »

I guess we know where Conn's mandrels wound up...
ttf_harrison.t.reed
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Why Coprion?

Post by ttf_harrison.t.reed »

Now does "made thin" mean they do it during the electro forming, or are they made thin afterwards, I wonder.

Being able to control the thickness at the flare during the formation of the bell would give incredibly consistent results.
ttf_BGuttman
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Why Coprion?

Post by ttf_BGuttman »

Quote from: harrison.t.reed on Aug 12, 2017, 09:30PMNow does "made thin" mean they do it during the electro forming, or are they made thin afterwards, I wonder.

Being able to control the thickness at the flare during the formation of the bell would give incredibly consistent results.
There are ways to control thickness during electroplating (electroforming).  Or you can use the traditional way of machining.  I have no idea which Conn used.
ttf_Arrowhead99
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Why Coprion?

Post by ttf_Arrowhead99 »

I don't think the Coprion bells were a bad idea at all. To me, it's no different than a rose brass bell being offered on a modern horn. There are some things that Conn did that are more perplexing than the Coprion bells (such as... why on a 4H did they put the slide brace at the very top of the slide creating an awkward "throw?" or instead of standard weight slides or lightweight slide, why not just have something in-between to please everyone? Image but i'm getting away from the topic of the thread)
ttf_JohnL
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Why Coprion?

Post by ttf_JohnL »

Quote from: BGuttman on Aug 12, 2017, 08:30PMI guess we know where Conn's mandrels wound up...I think that's where there always were.
ttf_The Sheriff
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Why Coprion?

Post by ttf_The Sheriff »

Quote from: JohnL on Aug 13, 2017, 12:02PMI think that's where there always were.
===

I believe you are correct. Anderson always made the coprion bells for Conn.

----
ttf_Stan
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Why Coprion?

Post by ttf_Stan »

I've got one that's going on the market soon, and some of these posts are spot-on.  The horn gives way more feedback than any brass bell I've ever played.  When you stop playing, the bell keeps vibrating for several seconds on some notes.  In a small room, you can almost feel the sound coming out of the bell reverberating around you.  Those students horns might not play like that, but the small bore Conns with the Coprion bells (10H and 12H) are strange and wonderful beasts.

Stan
ttf_elmsandr
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Why Coprion?

Post by ttf_elmsandr »

Quote from: harrison.t.reed on Aug 12, 2017, 11:25AMEuphanasia, I had to just send that emoji guy back at ya, I'm not too much worried about it beyond that. You got me wishing I could try a copper bell now.

That is a bummer about them only being used on student trombones.
...
I seem to remember that they started on the pro horns and found their way to the student horns when the pro horns kinda failed in the market.  Of course, I was born after this time period and my information is entirely second hand at best.  I do own a prototype 10H that I got from Cliff Ferree...  Crazy horn.  The prototype had some elements that were more towards its later 18H student model.  Interesting horn.  Unfortunately that flare got broken several years back, and I had to swap it out.

Quote...

I have a feeling Conn and it's staff knew exactly what they were doing in the 30s through the 60s. When you're buffing out the area where you've connected the flare to the stem (or whatever kind of bell you're working on) and accidentally overdo it, but then put it on a horn anyways, you'd notice pretty fast that your mistake was a stroke of genius, even if you don't know why, and unfortunately even if you don't write it down or tell your replacement in abilene what your trick was.
...

As the entire Coprion experiment kinda shows, they didn't exactly know.  They experimented and allowed the market to provide feedback.  Same as any smart business.  GM knew how to make cars and still decided to go with the Nova, so that's how it goes sometimes.

Cheers,
Andy
ttf_BillO
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Why Coprion?

Post by ttf_BillO »

Quote from: elmsandr on Aug 16, 2017, 12:20PMGM knew how to make cars and still decided to go with the Nova, so that's how it goes sometimes.
You must be talking about the NUMMI version from the '80s.  Early Novas and Chevy II's were nice cars in their time and are classics now.
ttf_elmsandr
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Why Coprion?

Post by ttf_elmsandr »

Quote from: BillO on Aug 16, 2017, 12:34PMYou must be talking about the NUMMI version from the '80s.  Early Novas and Chevy II's were nice cars in their time and are classics now.
/derails the thread further... I guess that's why they sold about 1/10th of them that they thought they were going to and the revolutionary processes for making and shipping them were completely scrapped.  The Corvair was a fun car to drive too and not as dangerous as was made out to be.  Doesn't make either of them a success.

Doesn't mean there aren't good elements to the design that people find attractive.  A 10H is a really fun horn.  If you like a 6H, I highly suggest that you pick one up.  I don't suggest that you make it your only horn or bring it to a first rehearsal with a new band.  Still pretty much failed in the market.

Cheers,
Andy
ttf_BillO
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Why Coprion?

Post by ttf_BillO »

Quote from: elmsandr on Aug 17, 2017, 05:54AM/derails the thread further...
To avoid this further - see here: http://tromboneforum.org/index.php/topic,101674.0.html
ttf_Posaunus
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Why Coprion?

Post by ttf_Posaunus »

Quote from: elmsandr on Aug 17, 2017, 05:54AM...the revolutionary processes for making and shipping them were completely scrapped. 

Or are you possibly referring to the Saturn, and not the pretty successful Nova? 
ttf_Stan
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Why Coprion?

Post by ttf_Stan »

Quote from: elmsandr on Aug 17, 2017, 05:54AM don't suggest that you make it your only horn or bring it to a first rehearsal with a new band.  Still pretty much failed in the market.


I've wondered about this before. I love my Coprion trombone, and it plays better than any 4H I've played. BUT, it's not my only horn. When I remember the Conn lineup in the 40s and 50s, versatility was key.  One player might be expected to use the same tenor as any part in a jazz band, a dance orchestra, or even a symphony orchestra. A Coprion tenor just won't work like that.  It's too wild, and too sassy.  I've wondered if the market today, with an eye for horns that are specialized towards specific tasks, would have treated the copper Conns differently.  I'm leaning towards yes, just because I won't personally see them for sale very often.

Stan
ttf_hyperbolica
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Why Coprion?

Post by ttf_hyperbolica »

I actually called Anderson Plating, and they said a raw bell costs $57. But then you have to trim to size and roll the bead. Amazing. $57. Get you a brand new coprion.
ttf_Gabe Langfur
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Why Coprion?

Post by ttf_Gabe Langfur »

Quote from: Euphanasia on Aug 12, 2017, 07:23AMI don't think any manufacturer actually works with varying thicknesses of metal to enhance the sound--not even a Bach "Stradivarius."  Image 
Sorry, but you're 100% wrong. As was alluded to in the Rath quote, 2-piece bells are routinely made with different thicknesses for the flare and stem. And that's just the tip of the iceberg.


QuoteDiffering thicknesses and hardnesses are a by-product of manufacturing techniques. Some designs--notably one-piece bells--are bound to be asymmetrical in both hardness and thickness because of the amount of stretching that occurs.

Yes and no...there are many manufacturing techniques that can be used to make a bell - and most other parts of a brass instrument for that matter. Which techniques are selected have a lot to do with the kinds of variation you end up with and how they affect the playing characteristics of the final product. Hand-hammering a one-piece bell leaves it thinner at then end, and that's a good thing for most professionals. You can make a one-piece bell in a more automated process that leaves it more uniform.

Another factor is cost; cheaper manufacturing techniques that leave the instrument good but less satisfying for the discerning player are used for student lines that have to be sold at a lower price point. Like coprion bells that you can get in 2017 for $57.

Sometimes the dog wags the tail, and sometimes the tail wags the dog.
ttf_Euphanasia
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Why Coprion?

Post by ttf_Euphanasia »

Quote from: Gabe Langfur on Aug 19, 2017, 09:03AMSorry, but you're 100% wrong. As was alluded to in the Rath quote, 2-piece bells are routinely made with different thicknesses for the flare and stem. And that's just the tip of the iceberg.



Well gee, Gabe--thanks for dredging up a week-old post and re-stating something that I've already acknowledged.  Image

So what's your point in the context of Coprion bells?  As I noted before, I now understand that some boutique manufacturers use different thicknesses as a way of manipulating the sound. However, that's a tiny fraction of what's being manufactured today, and I don't believe that was the practice when Conn was actively marketing Coprion bells. The majority of manufacturers have always, and continue to choose a gauge of metal, build a horn, and only thin the metal when necessary for cosmetic purposes. My point was, Coprion bells don't appear to be selectively thinned to enhance the sound, that differing thicknesses aren't achieved by selective buffing, and that a bell with uniform thickness and hardness is not "lame."

There's no "iceberg" of selectively-thinned bells in mainstream trombone manufacturing. Just a tip.
ttf_Gabe Langfur
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Why Coprion?

Post by ttf_Gabe Langfur »

Quote from: Euphanasia on Aug 19, 2017, 09:23AMHowever, that's a tiny fraction of what's being manufactured today, and I don't believe that was the practice when Conn was actively marketing Coprion bells.
Sorry, I just started looking at this topic and I wanted to correct some false statements.

I don't believe that is a tiny fraction of what's being manufactured today, and it's not a new idea. A major design element of the classic Conn 88H is that the stem of the bell is significantly thinner than the flare, and I'll bet if you look at many other Conn models you'll find the same or similar design elements.

QuoteThe majority of manufacturers have always, and continue to choose a gauge of metal, build a horn, and only thin the metal when necessary for cosmetic purposes.

I don't think this is ever the order of events or priorities. And what cosmetic purpose does thinning the metal serve?

As to Coprion, my guess - and it's only a guess, though it's educated by having worked in the industry - is that somebody at Conn found out just how cheaply they could get electroformed copper bells and got the go-ahead to give it a try, starting with student models.
ttf_Euphanasia
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Why Coprion?

Post by ttf_Euphanasia »

Quote from: Gabe Langfur on Aug 19, 2017, 10:12AM
And what cosmetic purpose does thinning the metal serve?


On classic 88Hs, it removes the bead left behind when the flare is soldered to the stem. That and the stem seam are the thinnest spots in those horns--sometimes too thin. Now, knowing the way Conn tended to do things, I would imagine that there's a sound-based principle regarding where the stem-to-flare seam is placed, where the braces are placed, where the stem seam is oriented relative to the braces, etc. Their engineering work was brilliant. However, I don't think selective buffing or hardening was something did on their assembly-line horns.

I would be VERY surprised if the stem and the flare on an 88H weren't cut out of the same sheet of brass alloy.
ttf_Gabe Langfur
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Why Coprion?

Post by ttf_Gabe Langfur »

Quote from: Euphanasia on Aug 19, 2017, 12:52PMOn classic 88Hs, it removes the bead left behind when the flare is soldered to the stem. That and the stem seam are the thinnest spots in those horns--sometimes too thin. Now, knowing the way Conn tended to do things, I would imagine that there's a sound-based principle regarding where the stem-to-flare seam is placed, where the braces are placed, where the stem seam is oriented relative to the braces, etc. Their engineering work was brilliant. However, I don't think selective buffing or hardening was something did on their assembly-line horns.

I think you have some inaccurate assumptions about how traditional brass instrument bells are made. I watched Steve Shires make countless bells, including the 2RVE and 2RVET7, his recreation of the classic Elkhart 8H/88H bells.

First of all, the flare and stem are not soldered together, they're brazed. Similar process conceptually, very different process in practice, and it doesn't leave behind the kind of extra material soldering often does.

What is left behind is a thicker section around the brazing seam where the notches overlap. That thicker section is not resolved by sanding but in the process of spinning the bell on the mandrel, mounted on a large lathe. Steve uses a tool of his own creation: a thick steel rod with a flattened and gently tapered point mounted in a sawed-off baseball bat. While the bell is spinning he flattens out that seam by going over it multiple times. This is a full-body effort, as it takes considerable force to do it - but too much force will rip the metal, especially the thinner metal of the flare of a 2RVE. This is not an exact science, and it's easy for the seam to end up thinner than the surrounding brass and thinner than it should be.

There is some sanding after that, but it's over the whole surface of the bell to even it out. On some models, Steve sands more in certain places in order to thin them further.

QuoteI would be VERY surprised if the stem and the flare on an 88H weren't cut out of the same sheet of brass alloy.
Maybe the modern ones are, but Steve took detailed measurements of many Elkhart 8H and 88H bells, and he is positive they weren't.
ttf_Gabe Langfur
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Post by ttf_Gabe Langfur »

The seam in the stem is flattened at the Shires factory using a machine called a seam roller that looks like a medieval torture device. I would imagine that it was done by hammering in some factories.
ttf_Euphanasia
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Post by ttf_Euphanasia »

Quote from: Gabe Langfur on Aug 19, 2017, 01:39PM
I think you have some inaccurate assumptions about how traditional brass instrument bells are made. I watched Steve Shires make countless bells, including the 2RVE and 2RVET7, his recreation of the classic Elkhart 8H/88H bells.

First of all, the flare and stem are not soldered together, they're brazed. Similar process conceptually, very different process in practice, and it doesn't leave behind the kind of extra material soldering often does.
Yes, I'm aware of that. Technically, it'a "hard soldering" since what's used isn't brass. It's a silver/copper alloy. I've attached flares to stems several times using hard silver solder (not silver-bearing solder).

Quote from: Gabe Langfur on Aug 19, 2017, 01:39PMWhat is left behind is a thicker section around the brazing seam where the notches overlap. That thicker section is not resolved by sanding but in the process of spinning the bell on the mandrel, mounted on a large lathe. Steve uses a tool of his own creation: a thick steel rod with a flattened and gently tapered point mounted in a sawed-off baseball bat. While the bell is spinning he flattens out that seam by going over it multiple times. This is a full-body effort, as it takes considerable force to do it - but too much force will rip the metal, especially the thinner metal of the flare of a 2RVE. This is not an exact science, and it's easy for the seam to end up thinner than the surrounding brass and thinner than it should be.
I've seen the "How it's Made" episode where the Shires trombone is made.  Image It does look like it takes a lot of effort to bring that seam down. My point is, though, that you can't just affect the seam. As you've noted, it's easy to make the metal too thin because you're working the seam, and the surrounding metal.




ttf_jnoxon
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Post by ttf_jnoxon »

A long story short. A friend had a Minnick .500 bore upper section with no bell. He really liked the look of the comprising Conn bells. I had a bell in the shop that we soldered on the bell section and it had a beautiful clear clean sound like I had never heard before. I just loved the sound. Well I had a Williams model 4 (.490 bore) with no bell. So I asked my buddy John Duda to make me a copper bell for the model 4.  He did after about 2 years of wrangling. So I have this on thec 4 that I play most of the time. It started as a flugel horn bell blank about 12" wide. So I ended up with a 7 3/8 diameter bell that has most clear, clean, sound I have ever found. Everyone said it won't blend blah blah and so on. Once you hear it is a beautiful sounding bell!

At the curve by the flair it is about .012 very very thin other places it is thick or thinner because of the manufacturing process. But I couldn't ask for a better sound that really blends very well. So the experiment was well worth doing! That's how we learn about making horns by experimenting!
ttf_jnoxon
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Why Coprion?

Post by ttf_jnoxon »

A long story short. A friend had a Minnick .500 bore upper section with no bell. He really liked the look of the comprising Conn bells. I had a bell in the shop that we soldered on the bell section and it had a beautiful clear clean sound like I had never heard before. I just loved the sound. Well I had a Williams model 4 (.490 bore) with no bell. So I asked my buddy John Duda to make me a copper bell for the model 4.  He did after about 2 years of wrangling. So I have this on thec 4 that I play most of the time. It started as a flugel horn bell blank about 12" wide. So I ended up with a 7 3/8 diameter bell that has most clear, clean, sound I have ever found. Everyone said it won't blend blah blah and so on. Once you hear it is a beautiful sounding bell!

At the curve by the flair it is about .012 very very thin other places it is thick or thinner because of the manufacturing process. But I couldn't ask for a better sound that really blends very well. So the experiment was well worth doing! That's how we learn about making horns by experimenting!
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