"Symphony" Eb helicon

[imperialbari]

Isn’t 0.600" pretty exactly 15.25mm? Not totally unlikely.

I have all the way been sceptic about using bits from larger bore instruments on a small bore instrument. The best solution, in my distant opinion, would be to let bloke make a neck from scratch. He will hate to do it, but then it only took two attempts to make one for his own Buescher CC. Bits will be hard to find, so let that function be incorporated in the neck. That will make the instrument individual for your playing, but so be it. The question is whether the receiver shall be for the small Besson type stems. That probably would be best, but the best compromise would rather be a receiver for American size stems.

The element to be patented in the US may have been the long stay.

Some years ago somebody posted photos of a valve block saver for a sousaphone in a gig bag. I think it was a wooden block milled out to save the piston stems from being bent. It then had been covered in naugahyde or something in that direction.

You could make a block out of styrofoam, which you carved to hold the valve stems and the tip of the lower leadpipe. Some satin woven fabric could be used as cover. A strap with velcro could keep it secured during storage and transport.

Klaus

[sloan]

Isn’t 0.600" pretty exactly 15.25mm? Not totally unlikely.

Yes, it is (don't you just love those calipers with a button to switch from sane measurements to insane ones?).

Now, the question is: which of these tubing sizes (I.D. = 0.600" in the US, or 15.25mm in Europe) was in common use in (say) 1900?

[imperialbari]

If you look at the more common bores in recent piston tubas also from the US then they vary by increments of slightly less than 0.020". I find this remarkably close to metric increments of 0.5".

Which country used which increments in tubing before WWI is a branch of industrial history too specialized for me.

Klaus

[Rick Denney]

If you look at the more common bores in recent piston tubas also from the US then they vary by increments of slightly less than 0.020". I find this remarkably close to metric increments of 0.5".

Which country used which increments in tubing before WWI is a branch of industrial history too specialized for me.

Klaus

Most dimensions that depended on machine tools were in traditional units (what are now SAE or "U.S. customary" units), because machine tools were often made in the U.S. and European countries had not yet adopted the Systeme Internationale (aka metric system), at least not for all measurements. As an example, most bicycle threaded fittings before WWII were in inches, not millimeters. Some were in inches and fractions of an inch, rather than in decimal inches, but this varied. Only the French were consistently metric after WWII.

0.600" does not line up with a fraction, but that might not mean anything. I would think 15.25 unusual, because later tubing seems to be supplied in .5mm increments, and with a .5mm wall thickness, one size has an outside diameter equal to the inside diameter of the next size, which is convenient for making instruments.

Rick "speculating" Denney

[David Richoux]

(putting on my Industrial Designer hat) (and pulling some assumptions from that same hat)

The problem with brass tube specs (Metric or Inch) is that it can be provided in just about any size you want - there is no real standard, and as far as my machinist handbooks show, there never was! It is more important to have tubes that fit tightly inside and outside of each other - regardless of the thickness - within the tolerance that the customer ( instrument maker) wants and the manufacturer (brass tube maker) can provide. Acoustic design demands and available tooling will limit sizes a bit, but still - it is all about tolerances.

Tubing can be made in a variety of ways - die extruding, roll forming and welding, and hydroforming - the precision of tubing needed for musical instruments is high, so there is probably not a huge variety of sizes in common use in the last century... but it would take a lot of time and measurements in collections around the world to see if that last statement is true!

[imperialbari]

Curiously,

The owner of this (obviously to me European-made) nickel-plated .600" bore Eb helicon also owns an American-made Eb helicon that sports a .600" bore.

Only saw this posting of bloke’s right now. And as this thread already is kind of a speculative mind-game, bloke’s observation let me see a potential answer to the puzzle that two Eb helicons from the same era, but apparently from two different continents, end up with the same bore, which is no longer standard, if it ever were.

European makers selling rotary valve blocks to US makers has been known at least since 1930 (Conn horns). US makers selling complete instruments to the European market has been known from around 1920. Aside from a few repair or rebuilding projects I am not aware of any larger trade in piston valve blocks across the Atlantic,

But the idea of combining parts from both sides of the pond may be older. Maybe the Symphony helicon only had its body made in Bohemia, whereas the valve block was added in the US. The same might even be the case with the Heinem helicon sold out of Kansas City - MO.

Klaus