Rotation Direction for Rotary Valves

jon112780 · Post by **jon112780** » Tue Oct 11, 2005 1:05 pm

I checked the archives and emailed a couple a few people, but still come back with mixed results. Some say it's a good idea and makes the airflow smoother, and others insist it's just a waste of time and money. I noticed on the newer PT6, PT10, PT15, as well as the Mirafone 186's and 188's, that they have their rotars going counter-clock-wise when the paddle is depressed. I have heard slight 'blurps' when depressing valves and wondered if it had someting to do with the whole rotar direction/airflow 'thing'.

I've had an estimates of $150-250 to: pop out the rotars, drill new holes, fill the old holes in, smooth the inside of the rotar casing, clean it and put the rotars back in. I guess it sounds like a relatively inexpensive way to improve the horn (and my playing) without spending a bundle. Does anyone have a horn that they did this too? Was there a noticable difference? Was it worth the money you spent? Any pictures?

thanks,
Jon Schultz
schul207@msu.edu
(517) 316-6898

tubaman5150 · Post by **tubaman5150** » Tue Oct 11, 2005 2:00 pm

I've played rotors turned in either direction and rotors that have been turned in both directions (ala Rudy Meinls and older Miraphones). I haven't noticed any measurable difference in any of the various setups. It is possible that I'm just not perceptive enough to notice any advantages of one direction over the other. Given the price it would cost to get them turned, I don't know if the procedure would be worth the money.

MaryAnn · Post by **MaryAnn** » Tue Oct 11, 2005 2:03 pm

I don't think it matters. The speed of airflow in the instrument is pretty slow. If you hear a "blurp" or whatever....I had to work on valve timing when I got my horn, because the lever throw was different from the previous horn, and I wasn't coordinating my embouchure change with my valve change very well. On my horn, I time the embouchure change (in a slur) to exactly when I bottom out the valve lever, to get the horn to do what I want. If my timing is off I get a blurp. I had to spend some time on this, to get the habit going.

MA

windshieldbug · Post by **windshieldbug** » Tue Oct 11, 2005 4:57 pm

I don't think it matters... either way you have the exactly the same size opening, not moving, miniscule, and then getting bigger. The only difference is which side of the valve casing that it takes place. We're talking millimeters of difference where it occurs. If your valves are vented, then as MA suggests, it's at most only a matter of synchronicity.

All of my rotary horns have valves going both ways and I've never noticed any difference at all. It sure seems that it will be a little more complex than you suggest; how will you connect the valves to your keys once you've switch the sides that they're rotated on? And how do you know you won't still have the same issue once you've gone and done all this work? Is there any way to try this on YOUR horn temporarily?

Paul S · Post by **Paul S** » Tue Oct 11, 2005 5:23 pm

think about it...

The rotors will all return to their original starting position in the opposite direction of the way you engaged them....

The airflow is going to see Both clockwise and counterclockwise rotation no matter which way the rotors are set.

Cameron Gates · Post by **Cameron Gates** » Tue Oct 11, 2005 8:40 pm

Paul S wrote:think about it...

The rotors will all return to their original starting position in the opposite direction of the way you engaged them....

The airflow is going to see Both clockwise and counterclockwise rotation no matter which way the rotors are set.

Well put Paul.

PS Paul, I got your message. I'll respond as soon as cox.net gets my outgoing mail working again.