For a late-1980s Hirsbrunner HB-2, I am looking to replace the old, triplene core rotors that have lost their quality over a long period of time and now cause the common, well-documented problems.
The ideal solution seems to be replacement with solid metal rotors. (Purchase of a new instrument is not an option/consideration.)
I have been in direct contact with Peter Hirsbrunner, but while doing some additional research I also stumbled across the site of the company that produces and supplies the valves to Hirsbrunner (J.Meinlschmidt GmbH http://www.jm-gmbh.de/deu/produkte7.htm).
The valves below with the “New Lubrication System” caught my attention.
Does anyone have any first-hand experience with these “new and improved” rotors, either positive or negative? Any useful insights and opinions are welcome.
Rough Translation from German:
Operational principle: Bringing in the lubricant is made by a spiral groove at the upper and lower camp pin. At the lower camp pin the oil is supplied from the outside by an axial drilling. By a radial drilling the lubricant arrives into the lubrication groove. At the upper camp pin the oil is brought directly into the lubrication groove. With the rotation of the change the oil distributes itself evenly between the sliding bearing surfaces. The oil remaining in the axial drilling serves as reservoir and provides thus for a sufficient amount of lubricant. An overdosing and thus oiling the valve are prevented by this principle.
Advantages: For the musician the care of the turning valves is substantially simplified. For oiling, the lower cap must be only removed and the lubricant from the outside be supplied. The self cleaning effect of the lubrication groove provides beyond that for a very high Wartungsfreundlichkeit. When playing the instrument the new lubrication system becomes apparent by a still suppler run of the changes
This is the result of a homogeneous lubricating film which is formed between the sliding bearing surfaces. An optimized finishing technique makes it possible to us to offer this option with only small extra costs so that for our customers a very good cost-performance ratio is obtained. This innovation from the house Meinlschmidt is protected by a patent.
(And, although not what I am considering, the carbon rotor was also of interest – unless I completely botched my very weak German and misunderstood what I read/saw. Any experience with these? Anyone?)
Thanks in advance for the assistance.
Cheers