Fun with Machines

[Full Metal Ratchet]

Hi there fellow tubists/tubaists (did we ever clear up that controversy?),

I went to visit my brother (a machinist) for the weekend and we decided to make a big *** mouthpiece, because....well....because we could.

We modeled my Schilke Helleberg's cup with a FARO arm and increased the bowl diameter to ~34.5, and made the throat 9mm. The backbore and throat entry were adjusted to smooth things out and the rim was slightly flattened, ala Conn Helleberg of my youth. The only issue we had was resonance using the Morse taper fixture while cutting the rim (you can see chatter marks inside the rim). Next time we will use soft jaws on the cylindrical portion on the OD.

Here are a few pics.

http://www.fullmetalratchet.com/Music/Tuba/

This was made for the fun of it and we have no intentions of marketing anything. We made it big because I don't currently own a large mouthpiece and I wanted to shoot for the moon! It's got some easy low end that's for sure. The jury is still out while I learn to play on this thing.

Edit: Sorry, but we do not take requests or orders. The machine time, programming, and labor would have been several hundred dollars if I wasn't his brother.

[Full Metal Ratchet]

Tried that once, didn't like the result.

[Ben]

How long did the process take? It looks like you made/were planning on multiple pieces, any variations you decided to make? I wish I had access to a machine like this to play around with some ideas in my head. FUN!

[Full Metal Ratchet]

How long did the process take? It looks like you made/were planning on multiple pieces, any variations you decided to make? I wish I had access to a machine like this to play around with some ideas in my head. FUN!

There was a lot of time wasting things like setting up the FARO arm, figuring out a way to clamp the mouthpiece to the table, tweaking in Solidworks, editing the machine code, finding suitable stock, determining our workflow/goals, re-machining at slower speeds due to resonance. From start to finished product, about 8 hours. Actual machine time per part once it was set up, about 45 minutes. The lathe is a toolroom lathe, but can hold 8 tools. We didn't install two necessary drill bits and index them, instead choosing to manually drill with the tailstock for clearance of the boring bar used on the taper and bowl. We were turning 200 to 500 rpm out of 1500. This lathe won't turn fast enough to break chips at the small cuts we were taking (even without resonance limiting us), so we had to clean the metal spaghetti out every pass. If we bored some soft jaws to hold the mouthpiece, used a solid carbide boring bar, and fully set up the tool holder, the machine time would be about 20 minutes per mouthpiece total with a pause in the middle to flip the mouthpiece around. With a high speed production machine with dual spindles you could do it in a one step process in about 5 minutes or less.

Due to us using a Morse taper holder that was machined in place using a 3 jaw chuck, we turned the OD and inner shank on two mouthpieces in a row in case we screwed one up. If we did one at a time, we would have to remachine the previously removed Morse taper holder during the second process, since the 3 jaw chuck can't perfectly center anything. This would require an extra work step.

The 2nd mouthpiece is identical on the outside, but remains a solid piece of metal except for the shank. My brother is keeping it as a souvenir.

[Full Metal Ratchet]

Is the throat as sharp as it looks?

We had to make a 2nd pass due to some bad chatter marks (much worse than in the picture). This left a 0.002" ridge at the throat entrance since we didn't re-machine the taper. The flash is also playing tricks. It is a smooth transition, other than the aforementioned ridge. Is that what you meant?

[Full Metal Ratchet]

After some more playing I think I have a verdict.

Good for below 4th line F. Fuzzy sound/few overtones in the high range unless you are really working hard to alter your embouchure. Slots well below the staff. No real character to the sound, but gains extra authority/core below the staff. It might be good for particular music, but would not be a good all around mouthpiece.