michael_glenn wrote:I've played my HB-2 in direct sunlight on a 95 degree day. I've never had issues with the valves locking up. Any time they feel slightly sluggish, it's because I forgot to oil a spot.
I have to concur! I have never had any problem with my HB-2 (composite) valves.
Perhaps relevant to this thread, perhaps a hijack:
My Mirafone 186 BBb from 1972 has rotors that are gray. No one who has ever worked on this horn has any idea what they are, other than they have never seen anything like it. They are tightly sealed, and work terrific. They never bind, and require minimal maintenance. But, they are a battleship gray. Are these some sort of plastic? They weigh about the same as would a regular brass rotor [by feel, not on a scale] Is this a plastic coating? Or something else? I realize you would need to see and touch them to come up with a real answer, but has anyone seen something like I describe? Something carbon fiber?
Ferguson wrote:Those troublesome rotors might not be difficult to fix. Peter Hirsbrunner recommended heating the rotors with a hair dryer and then lapping them
-F
I used to have an HB6 with the Nylon Rotors and it would hang up on very hot days at the Hollywood Bowl (95 plus degrees). Al Baer hot lapped them for me (he said he used a torch) and they never hung up on me again. I was worried the rotors would be ruined but they still had good compression and were very fast after he finished the job. The playability wasn't affected at all. Al did the same lap job on his personal HB6 as well.
I had a second HB6 for a while that had replacement brass rotors and, although they fit well, the tuba did not play well since the ports were much larger than the Nylon rotors. I ordered a set of Nylon rotors from Hirsbrunner and had Kevin Powers fit them to the casings. That tuba tuba played much better, almost as good as my #1 HB6. Never any sticking problems with those valves either.
Ferguson wrote:Those troublesome rotors might not be difficult to fix. Peter Hirsbrunner recommended heating the rotors with a hair dryer and then lapping them
-F
Yes... I DID resolve the problems with the composite Hirsbrunner rotors by elevating the temperature of the entire rotor assembly to perhaps 120 degrees (or so) while lapping it. It's just a shame to have to resort to removing material from the rotors of an expensive horn.
Dan Schultz
"The Village Tinker" http://www.thevillagetinker.com" target="_blank
Current 'stable'... Rudolf Meinl 5/4, Marzan (by Willson) euph, King 2341, Alphorn, and other strange stuff.
I have an HB2. The valves were lapped under heat for the previous owner, but on 95+ degree days, they bind after a bit of playing.
My solution is to pour a few oz. of water down the mouth pipe (the mouthpiece makes a wonderful funnel). I then slosh it back and forth through the valveset while wiggling all the valves. When I'm finished I pull the tuning slide and dump the water. This takes some heat out of the system, and unbinds the valves. I can do it in under a minute.
I now do this between pieces as a preventive measure every half hour on those really hot days.
To all those, that have had replaced theyr tryplen valves with brass rotors. Did the sound of the instrument change? If so, les or more overtones; more or less core to the sound?
I've played a few of these horns and have not once experienced the sticking issue *and* they have universally been the nicest fastest feeling rotors I've ever experienced.
There is no negative effect on the sound with these rotors
It's worth noting that Meinlschmidt made those valves and now makes a modern version that is made of carbon rather than plastic. Anyone can contact them and order new valves or even complete valvesets.
Short version: I think the sticking problem might be an overblown issue especially when compared to the positive attributes.
Slightly longer version: Any horn that has these valves attached to it is likely something very rare and special.. if it bothers you that much then buy a new set of rotors from Meinlschmidt.
I’m not complaining about the tryplen rotors.... i haven’t had problems with them up to date. I’m just wondering about a possible influence on the sound if you replace them with traditional brass rotors. To make it clear: my tryplen valved tuba is a very fine instrument in every aspect and i wouldn't want it to change. To me it would be just logical to have a different sound result, with all that non resonating material in the valve cluster. I know a lot of french horn players who swear on massive brass rotors and reject any lighter than 'Meinlschmidt' standard concepts.
There are whole instruments made out of plastic that still sound like their respective instrument. Plastic trumpets, trombones, piccolos, tubas, recorders, etc...
Interestingly, metal clarinets while often not the best engineered designs, universally sound just like a clarinet.
Chuck Dallenbach often uses a carbon fiber bell.. contrary to conventional wisdom carbon fiber is basically just a fancy form of fiberglass. In both cases the material holding it all together is a resin(plastic).
The big difference between materials isn't sonic but the fact that you need to use different manufacturing techniques to work different materials. Also, it looks different and most people listen with their eyes.
I played a Hirsbrunner 4/4 %-rotor CC in college that had the tryplen rotors, and had no difficulties with it. Later, I played one while stationed in Atlanta, Georgia, a considerably warmer climate. I found that, if the end bearings are tight, the valve is clean, and the valve is really well-oiled, the rotor does not bind. The nylon center is affected by temperature, but also by moisture. If you clean the valves, thoroughly dry them, then oil the entire surface of the valve, including the nylon portion, the oil will repel moisture. At an outdoor venue in 95 degrees F heat and as much humidity, the valves did not stick. I worked on that same instrument for the Army Ground Forces Band nearly 15 years later, after I was retired from the Army, as they were having sticking problems with the rotors. The bearings had worn to where there was a little play in them, and the valves were dirty. I swedged and re-fit the bearings so that the valves ran true again with no play, and cleaned it as thoroughly as humanly possible, and the instrument played like new again, with no valve sticking issues.
I would personally have no qualms whatsoever about owning and playing one of these instruments with tryplen valves. They just do not tolerate dirt and loose bearings very well, so they must be well-maintained.
I had wondered why the Hirsbrunners would build an instrument with such tight tolerances in the valves that a hot day could affect their performance. Then, in 1993 I visited Sumiswald one June day, when it was misty and about 48 degrees F. I don't think it ever gets hot there!
