TubeNet

I hava a question about York Grand rapids front bell Bb tubas:
Do they use to make these tubas with the front bell in "one piece"?
I have found one, but I do not know if the "one piece bell" is custom or regular

Roger

I ment nondetachable
The instrument I mean has a connector around the bell - very much like the picture you posted.
It has 4 front-action valves though.

Roger

The one-piece-bells are not actually bent. They are made from a set of cut brass sheet patterns that are brazed together and shaped into rough recording bell form. The bell is then put in a draw-die where its flair is then malleted out further. A large flaired lead plug is then pulled down the throat and stack of the bell forcing it into the shape dictated by the die that incases the entire bell. Once the bell is removed from the die, the flair is then fixed onto a bell flair shaped mandrel and finally spun smooth and the bead finished using a spinning lathe. Check out this Youtube link at 2:55 and you will see a brief glimpse of the process.

http://www.youtube.com/watch?v=a3IznMWn ... re=related

Daniel C. "Hoping not to come accross as Mr. Know-it-all" Oberloh

goodgigs wrote:Dan,
Hi, I'm a little confused. Do you mean to say that the bell can be spun with its tail sticking out at forty five degrees without smacking
the lathe operator in the face as it goes by ???

Yup.
Take a look at the H.N.White site. One of the top images shows a one-piece bell in the left of the image. The lathes can be pretty large as you will see in the pics shown. But I have seen much larger then these.
http://www.hnwhite.com/Bell%20Construct ... rtment.htm

goodgigs wrote:So Dan, thanks for furthering the discussion as your opinion carries a lot of weight with me.
Nobody is doing "harder" brass restoration with more consistently excellent results then you - anywhere !

You are welcome, thank you for the kind words. I guess I'm quite the horn geek.

goodgigs wrote:PS I just took My first hands on dent machine lesson. Well at least now I think I have a clue !

Way to go!!! Just remember to be patent. Take your time and focus on the angle of your approach to avoid putting tool creases in the bell flair. And don't use too much pressure. If you are ever looking for an extra 2¢ on use of the dent machine, feel free to give me a shout. Best of luck.

Daniel C. Oberloh
Oberloh Woodwind and Brass Works
http://www.oberloh.com" target="_blank

At which speed do these bell spinning lathes run (rpm)?

Klaus