Titanium GW piece Wieght?

[Rick Denney]

Do GW use a specific Titanium alloy which would increase the weight over aircraft grade stuff I'm thinking of? Am I missing something?

Titanium has about half the density of steel, which puts it between aluminum and steel. Ivan tells me that his titanium alloy is 6AL/4V, which is 6% aluminum and 4% vanadium. But that doesn't matter--all titanium alloys have about the same density. By the way, 6AL/4V is commonly used in aircraft and high-end titanium bicycles. Properly worked and heat-treated, it's as strong as hardened steel but at half the weight.

But it's only about half as stiff as steel, making its specific stiffness about the same as steel (and aluminum, for that matter). Stiffness, like density, is not significantly affected by alloy or hardening treatments.

Rick "thinking strength is unimportant, but modulus of elasticity is" Denney

Edit: I changed the alloy percentages above. I was confusing 6/4 with 3/2.5, both of which are are used in aircraft and high-end bikes. Ivan straightened me out.

[Rick Denney]

I am an out of work aircraft mechanic and from some of the classroom training I have had in the past I remember something about the comparison between stainless steel and titanium of equal size would be equal strength but a 30% lower weight for the titanium.

Titanium is 280 pounds/cubic foot, and steel is 490 pounds/cubic foot. That's about 57% as dense. So the right answer is a little between my approximation of half the density and yours of 70%.

The strength is indeed the same, and maybe stronger than many stainless alloys.

The modulus of elasticity, though is about 16,000 ksi, which is about half of steel's 29,000 ksi.

Resonance of the mouthpiece is a function of mass, stiffness (both of the material and of the design), and damping. Metals have very little damping, so that's not really a factor--they are highly elastic and ring like a bell.

Mass lowers the excursion of vibration and the resonant frequency (up to a point). Stiffer materials and designs would increase the resonant frequency. But I can't see how that matters--the impedance of the metal and the impedance of the air inside are such a mismatch that I would think each deaf to the other. When that mouthpiece rings, it's at very high frequency--frequencies that don't resonate in the tuba to any audible extent. I think tuba sound may extend as high as 1000 Hz in its overtones, but that is a couple of octaves under the ringing tone I remember in my head. I'll have to ring some when I get home.

Rick "who thinks the G&W mouthpiece are good, but who can't explain how the material makes them so, other than stainless feels great" Denney

[Tom B.]

sbring wrote:

My stainless steel Bora weighs about 370 g. Using Rick's info, that would make a titanium piece about 210 g. For comparison, a standard Conn Helleberg is 160 and a Kellyberg is 35 g.

I saw the G&W mouthpieces at the Army conference and came away thinking there was a lot of metal in them. Sven's post confirms my thoughts--the stainless steel models weigh more than twice what my Conn Helleberg does.

The redesigned G&W site has a couple things that caught my eye:

1. The new Alan Baer model has a shape similar to my Helleberg (which results in less mass);
2. They are describing their current line of stainless tuba mouthpieces as "heavyweight"; and,
3. The titanium mouthpieces are available as heavyweight or lightweight.

Could a "lightweight" stainless mouthpiece be in the works? If so, will it be shaped more like a Helleberg?

Merely speculating.

Tom

[Ivan Giddings]

Our current plans for light weight tuba mouthpieces will extend to our signature model mouthpieces only. We are focused on our trombone line of mouthpieces, and we will be offering the entire line in Heavy weight, and light weight models. Actually I'm in the process of putting up photos of the light weight trombone mouthpieces. If you check our website early next week you will see our lighter trombone mouthpieces.

We are also working on a Signature model mouthpiece for trombone players. This mouthpiece will be the Harry Watters Signature model mouthpiece.

We do have plans to start working on the Alan Baer Signature F tuba mouthpiece this will be light weight. While we are putting the finishing touches on the Alan Baer signature CC tuba mouthpiece, which by the way are coming out very nice.

Ivan