Posted by Rick Denney on August 28, 2001 at 16:56:57:
I was fiddling around with a new scanner last night, and a new macro photography setup over the weekend. I ended up with a close-up picture of my valve linkages that I made for the Miraphone. It is the same as has been used by many folks, and I've described it several times and had a few requests for pictures. So, here's a picture.
The pink blob at the top of the ball-joint is the plastic in the lock nut that bubbled out when I did a bit of soldering at the base of the stop arm. I screwed in a section of threaded rod, through the ball, the shaped washer that goes at the base of the ball, and a section of brass tubing that spaces the ball above the stop-arm screw for clearance. I soldered the brass tube to the stop arm to make it that much more rigid. A brass dome nut would be more decorative, but what do I care?
The two ball ends are connected by a threaded rod that has a brass tube slipped over it. After assembly, I bent it to improve the clearance a bit. Not all tubas require this.
Most of this you have to make up as you go, unless you want to spend a bunch extra for more favorably configured stop arms or the like. I made do with what I had.
Rick "Mark Finley's Monsterweights site has good pictures of similar linkages on a Piggy" Denney