String Linkage on on rotary Tubas

[rodgeman]

Has anyone converted a rotary tuba to string linkage?

I once had a bass trombone (Bach Strad 50B3) converted from mechanical to string and it was great.

I have a Mirafone 186 BBb which the s type linkages are great but another thread got me wondering....

Thanks in advance for replies.

[NDSPTuba]

As a former horn player of 30 years, I'd only own string linkaged horns. They are far smoother than mechanical linkage and easier on the bearings as they create less of a side load when the valves are actuated. Yamaha had the best linkage, they started the articulated arm with string they are fast and smooth. Before then most horns had a solid bent arm with string.

[Dan Schultz]

As a former horn player of 30 years, I'd only own string linkaged horns. They are far smoother than mechanical linkage and easier on the bearings as they create less of a side load when the valves are actuated. Yamaha had the best linkage, they started the articulated arm with string they are fast and smooth. Before then most horns had a solid bent arm with string.

Both the Walter Sear and the Marzan tubas have an articulated string-bar. I can't see anything else working well.

As far as converting to strings.... there needs to be a lot of consideration given to the diameter of the stop arm vs. the mechanical advantage of the paddle levers. The stroke of the paddles on the string-operated rotors on my Marzan is very short... about 2/3rds of the paddle stroke of a Miraphone. It's very important to balance the rotary motion and the linear motion and I'm just guessing that one should allow a lot of time for prototyping rather than to try to use engineering principles.

[TUBAD83]

When I was in college I had a school issued Miraphone 186 BBb with string linkage. The valves on that horn were incredibly fast, smooth, and quiet. To this day, I have yet played a tuba that could match that old tuba and I often wonder why they stopped making them.

JJ

[bort]

Sounds like someone (if interested and serious) should get in touch with Miraphone, or one of the US vendors who are very friendly with them. Maybe Miraphone could supply parts?

[Art Hovey]

I had a Sear-Cerveny Piggy CC with string linkage for a while, and felt that the mechanical advantage was wrong. It was set up for very short finger stroke, which made those huge solid rotors seem more massive and sluggish than necessary. I made bushings to enlarge the part that the string wraps around on the rotor shaft. That lengthened the finger stroke and made the valves seem lighter and faster.

I gave up on rotary valves because for me they need cleaning just as often as pistons do, but require a lot more effort to clean.