Posted by js on June 12, 2003 at 00:06:18:
In Reply to: Re: Doug Elliott trombon mouthpiece posted by It... on June 11, 2003 at 20:28:52:
There are devices called "inside micrometers" that can accurately measure the inside diameters of things such as tapered mouthpiece receivers. Once the "large end" (end of instrument) and "small end" (origin of mouthpipe tube) inside diameters of a receiver have been measured and the "straight-through" length is determined, the angle and the start/stop points of that angle are all known.
As "It..." above stated, a good metal-working machinist can do this. A mouthpiece guy (though desirable) isn't absolutely necessary. Ask the machinist to leave everything about .002" too large to allow for fine sanding and buffing.