TubeNet

Hello all,

The subject has been clarified. Thank you to those that clarified it for me.

Merry Christmas and Happy Holidays!

All my best,

Joe

Can you (or anyone) please explain to me how to make a bell "by hand" instead of just using sheet brass, brazing the seams together, and spinning it onto a bell mandrel for the desired shape? Of course this is all made by the hands of individuals in the manufacturing process of making "manufactured" bells.
I'm confused.

My apologies for the confusion. As far as I am aware, production tubas typically have thicker sheets of brass they're made of, whereas "hand-made" (hand hammered) tubas have thinner sheets of brass. FWIW, almost every single "hand-made" tuba I've tried has weighed less than a "production" tuba. My large CC is a production tuba; I have pondered with the idea of what it would play like if I was to order a "hand-made" bell and replace the production bell.

In a (student) trumpet manufacturing videos I have seen, the bell flares appeared to be stamped/pressed into shape out of a disc, then joined to a cone. Much less hand work compared to the yamaha xeno manufacturing video on Youtube. I don't think it is quite like that for tubas, but that could be the idea.

Of course, putting a brass bell on a plastic tuba would be the described change (non-handmade to handmade)..

@ Curmudgeon: I did not know that that's how bells were made for both types of tubas. Thank you for the clarification. It is appreciated.

Darn. I was hoping someone had a new a simple way to make a tuba bell.

I toured the Bach factory in Elkhart a few weeks ago. What I saw cannot be described as TOTALLY hand-made. The high-end, one-piece (Strad and Artist) trumpet and trombone bells are formed to some really odd shape before they are brazed together and HAND HAMMERED into a basic shape before they are spun. This process is done to attempt to get a uniform thickness throughout the bell. There are a couple of annealing processes mixed in because brass work hardens as it is formed, stretched, and hammered. It's a VERY elaborate process.... one that I would never attempt at home!

Don't confuse 'hand-made' and 'hand-hammered' to mean there are no machines involved.

For an explanation of the difference between "spun" and "hand-hammered" bells, look e.g. on http://www.engelbert-schmid-horns.com. The first one is pressed from disk of brass and then spun on a form. The production of a so-called hand-hammered bell is shown in a nice video on http://www.schallstueck.de.
Hubert

While we're on the subject of bells...

What is a "seamless" bell? The Willson web site says that the bell on my horn is "seamless."

When i look inside my bell, I'm pretty sure that I see seams.

There is also the gusset seam vs the one common now. That is a different method. I would wager the plastic ones on plastic tubas are probably fairly machine-made.

"Seamless" usually refers to the entire bell being one piece, formed then (yes, it is a seam, but bear with me) soldered its entire length. Otherwise, like Besson bells, including mine, to make it easier to keep consistent thickness of the metal from the throat to the bell flare to the bead, on most bells the flare end is cut at some point in the process and one or two triangular gussets are brazed in. If the gussets come from the same lot of sheet stock, are brazed in with just enough brazing rod to make a strong joint, but not too much, and everything is annealed to the same hardness before being spun, I don't see that it makes the $X,XXX difference that some manufacturers would have players believe.

I know these tuba-making vids have been posted here before in the past. But they are perfect for this thread

B&S factory:

https://www.youtube.com/watch?v=WC9nrP7Mr7g
https://www.youtube.com/watch?v=dn0pZEtqnoo


Miraphone factory:

https://www.youtube.com/watch?v=t4mSNSd014g

Thanks for the link, that clarified my one-piece bell question!

Those videos are fascinating.

Hi Bort, Sorry, something went wrong, look at next post.
Hubert

Hi Bort,
Indeed Willson speaks of a seamless bell. Meant is the so-called "spun" bell (cf. the website of Engelbert Schmid as referred to earlier). The process starts with pressing (on a heavy hydraulic press) a roughly shaped bell form from a rather thick disk of brass. What comes out looks a bit like a long bucket. This is placed on a heavy metal template on the lathe and then spun into the final bell form. So, there is no soldered seam. It is a bit like blowing a bubble into a chewing gum. I have seen this process in the Willson factory, but cannot find a video of it.

The production of the hand-hammered bell starts from cutting a bell shape from a sheet of brass, folding it, soldering the halfs together (the seam). Then it is being hammered into a roughly shaped bell and finally spun on the lathe as well. That is the process shown in the video I have mentioned in an earlier post.

It is not easy to produce very thin "spun"/seamless bells with exact the same thickness everywhere (and no weak spots), because there is an enormous amount of stretching of the brass involved in this process. On average seamless/spun bells are somewhat thicker than hand-hammered bells.
Hubert

Thanks, this all makes a lot of sense now, and the horn shop website was very helpful.

I'm always amazed by the level of craftsmanship it takes to build or instruments. They *should* be expensive!