Rotary valves: Open Port Vs. Closed Port

Post Reply
Backbone
Posts: 89
Joined: Sun Apr 08, 2018 9:46 pm

Rotary valves: Open Port Vs. Closed Port

Post by Backbone » Mon Oct 07, 2019 3:09 pm

What exactly does open or closed port mean? Why are there these two types? :???:
Last edited by Backbone on Tue Oct 08, 2019 10:05 am, edited 1 time in total.
User avatar
Neo Bri
Posts: 937
Joined: Wed Mar 21, 2018 10:30 am
Location: Netherwhere
Contact:

Re: Rotory valves: Open Port Vs. Closed Port

Post by Neo Bri » Mon Oct 07, 2019 6:18 pm

I'd like a better explanation, too. I know the idea is a drilled hole in the valve wall designed to eliminate the 'pop' when going between sides. Or maybe that's 'venting.'
________________________________________________________
Get the word out! Make www.trombonechat.com our community!
tbonesullivan
Posts: 226
Joined: Tue Jul 02, 2019 9:06 am
Location: New Jersey
Contact:

Re: Rotory valves: Open Port Vs. Closed Port

Post by tbonesullivan » Mon Oct 07, 2019 7:20 pm

Where did you see this referenced? Can you link to a website?

There's several different things it can mean.

Generally it's used to refer to certain trombone models with F-attachments that use Rotary Valves. A certain maker (BACH) has for years used rotary valves that many feel are undersized in general, and have oval ports that just aren't big enough to do the job. So, one of the standard modifications that many repair shops offer is opening up the rotor ports.

Most other makers have moved to larger rotary valve designs, or improved rotor designs, which don't have these limitations. Even the Conn 88H, MADE AT THE SAME FACTORY, has nicely designed rotors. Yet Bach, like Harley Davidson and Gibson guitars, refuses to change things, so you want to upgrade to a more expensive model.
David S. - daveyboy37 from TTF
Bach 39 Alto, King 2103 / 3b, Yamaha YSL-640, Bach 42T, Kanstul 1570CR, Kanstul 1588CR, Yamaha YBL-612 RII, Sterling Perantucci 1056GH Euphonium, Yamaha YBB-631S Tuba
Livingston Symphony Orchestra NJ - Trombone
harrisonreed
Posts: 838
Joined: Fri Aug 17, 2018 12:18 pm
Location: Yokohama, Japan

Re: Rotory valves: Open Port Vs. Closed Port

Post by harrisonreed » Mon Oct 07, 2019 9:30 pm

Open ports means that the bore isn't constricted through the rotor interior paths. Techs can "open ports" up on a rotor so that there isn't a step down through the rotor, and then a massive step up to the larger F tubing on the other side. The other thing they might do is adjust the tubing entry angle so that the rotor entry and exit isn't extremely oval shaped.

Over sized rotors allow you to have larger pathways through the rotor, but there are other benefits/aspects. For one, a large rotor adds weight and might have a heavy valve cap. Another thing it's that you can have crazy pathways like the Minnick rotor or CL2000 rotor, both of which have very open pathways.
Bonearzt
Posts: 279
Joined: Thu Mar 22, 2018 7:40 am
Location: My Dungeon of Hell....Actually Texas
Contact:

Re: Rotory valves: Open Port Vs. Closed Port

Post by Bonearzt » Tue Oct 08, 2019 6:21 am

This sounds more like a mashup of two different thoughts.
"Open" and "closed" USUALLY refer to the configuration of the valve wrap. Closed meaning the compact wrap with several 180 deg. crooks, and open meaning the longer, less "coiled" configuration.
This also relates to the configuration of the knuckles on the rotor casing. "open" being the one that has the 180 deg. return knuckle coming from the valve section going back into the neck pipe, and "closed" having the 2 90 degree knuckles going into and out of the valve tubing.

As to "ports", that is in reference to the passageway in the rotor, and the rotor core itself can sometimes be ground out to increase the bore and allow more air to flow.

<<I know the idea is a drilled hole in the valve wall designed to eliminate the 'pop' when going between sides. Or maybe that's 'venting.'>> Correct Brian, "venting" is the elimination of the "pop" that you sometimes get when actuating the trigger, and drilling passages in various places allows this to occur.


Eric
Eric Edwards
Professional Instrument Repair
972.795.5784

"If you must choose between two evils, choose the one you haven't tried yet."
"Rather fail with honor than succeed by fraud." -Sophocles
GabeLangfur
Posts: 162
Joined: Fri Mar 23, 2018 7:20 am
Location: Boston, MA, USA
Contact:

Re: Rotory valves: Open Port Vs. Closed Port

Post by GabeLangfur » Tue Oct 08, 2019 7:29 am

Backbone wrote:
Mon Oct 07, 2019 3:09 pm
What exactly does open or closed port mean? Why are there these two types? :???:
Can you point to where you see these terms?

I am not an instrument designer, but I used to do sales for the Shires company. The Shires standard rotary valve may be one that you refer to as "open port." The ports in the valve are not completed by the rotor piece itself, but by the casing. This provides a little bit of venting, and it allows for a valve that is a little smaller (and therefore lighter) than it would be if the ports were contained entirely inside the rotors.
Backbone
Posts: 89
Joined: Sun Apr 08, 2018 9:46 pm

Re: Rotory valves: Open Port Vs. Closed Port

Post by Backbone » Tue Oct 08, 2019 8:37 am

GabeLangfur wrote:
Tue Oct 08, 2019 7:29 am
Backbone wrote:
Mon Oct 07, 2019 3:09 pm
What exactly does open or closed port mean? Why are there these two types? :???:
Can you point to where you see these terms?

I am not an instrument designer, but I used to do sales for the Shires company. The Shires standard rotary valve may be one that you refer to as "open port." The ports in the valve are not completed by the rotor piece itself, but by the casing. This provides a little bit of venting, and it allows for a valve that is a little smaller (and therefore lighter) than it would be if the ports were contained entirely inside the rotors.
https://www.instrumentinnovations.com/products

Click on the rotary valve link and read the descriptions. Seems Bonearzt has the answer.
Last edited by Backbone on Tue Oct 08, 2019 10:05 am, edited 1 time in total.
GabeLangfur
Posts: 162
Joined: Fri Mar 23, 2018 7:20 am
Location: Boston, MA, USA
Contact:

Re: Rotory valves: Open Port Vs. Closed Port

Post by GabeLangfur » Tue Oct 08, 2019 9:28 am

Huh. That's a weird way to label them. Instrument Innovations calls a valve with two 90 degree ports "closed port" and one 90 and one 180 degree ports "open port."

Steve Shires has long thought that 90/90 ports play more open than one 90 and one 180 degree turn, which is why you see that configuration on all Shires rotary valves. That makes it essentially impossible to get the valve tuning slide long enough for an E pull, however. With one 180 degree port, you get more straight tubing in the valve section, so an E pull is easy to design for.
tbonesullivan
Posts: 226
Joined: Tue Jul 02, 2019 9:06 am
Location: New Jersey
Contact:

Re: Rotary valves: Open Port Vs. Closed Port

Post by tbonesullivan » Tue Oct 08, 2019 10:57 am

I guess it comes down to how you were introduced to the valves. In general the "open" wraps use the 90/180 configuration, which is how they are on Bach, Conn, Yamaha, and Kanstul (now defunct). Also Willson and others make them that way.

Generally if you're looking to replace valves, you're not going to replace ones on a high end custom horn like an Edwards, Greehnoe, Shires, Rath, etc.

This reminds me of items that are for the right hand, but worn on the left side. Do you advertise it as left? right?
David S. - daveyboy37 from TTF
Bach 39 Alto, King 2103 / 3b, Yamaha YSL-640, Bach 42T, Kanstul 1570CR, Kanstul 1588CR, Yamaha YBL-612 RII, Sterling Perantucci 1056GH Euphonium, Yamaha YBB-631S Tuba
Livingston Symphony Orchestra NJ - Trombone
Schlitz
Posts: 231
Joined: Fri Mar 23, 2018 1:01 am

Re: Rotary valves: Open Port Vs. Closed Port

Post by Schlitz » Tue Oct 08, 2019 11:52 am

tbonesullivan wrote:
Tue Oct 08, 2019 10:57 am

Generally if you're looking to replace valves, you're not going to replace ones on a high end custom horn like an Edwards, Greehnoe, Shires, Rath, etc.
100% agreement. These valves are ideally suited for Bach hardware. A used Bach reconfigured with these valves is a manageable animal. Go further with a dual bore Shires bass slide. Helluva lot cheaper too.
User avatar
Tooloud
Posts: 69
Joined: Sat Mar 31, 2018 2:01 am

Re: Rotary valves: Open Port Vs. Closed Port

Post by Tooloud » Thu Oct 31, 2019 8:05 am

In favour of Bach / Conn and respective "derivatives": A smaller port produces a bit of resistance, that is needed to produce a substantial tone, or at least makes it easier for the player to make a sound, that can carry even in large halls.
Very open valves force the player to produce the resistance in his own embouchure in order to to make a sound, that is neither 'woofy' nor tubby'. For this reason the double valve Thayer grow out of fashion with trombonists, who don't want to sound like bad (french...) horns or euphoniums. ("Tuba on a stick"...)
No offense - but that is, what I watch in my surroundings. Maybe a bit euro-centric, maybe it is not the case in the US..
tbonesullivan
Posts: 226
Joined: Tue Jul 02, 2019 9:06 am
Location: New Jersey
Contact:

Re: Rotary valves: Open Port Vs. Closed Port

Post by tbonesullivan » Thu Oct 31, 2019 8:30 am

I have a Bach 42T, an I would definitely agree that it is open, and in some days getting the trigger register to speak is more difficult than on my other trombones, which all have some type of rotary valve. It's one of the aluminum core examples, so eventually it will need to be replaced, and I'm torn on whether to have a new design axial installed, or to go to a standard rotary.
David S. - daveyboy37 from TTF
Bach 39 Alto, King 2103 / 3b, Yamaha YSL-640, Bach 42T, Kanstul 1570CR, Kanstul 1588CR, Yamaha YBL-612 RII, Sterling Perantucci 1056GH Euphonium, Yamaha YBB-631S Tuba
Livingston Symphony Orchestra NJ - Trombone
User avatar
Matt K
Posts: 1522
Joined: Tue Mar 20, 2018 10:34 pm
Contact:

Re: Rotary valves: Open Port Vs. Closed Port

Post by Matt K » Thu Oct 31, 2019 8:59 am

tbonesullivan wrote:
Thu Oct 31, 2019 8:30 am
I have a Bach 42T, an I would definitely agree that it is open, and in some days getting the trigger register to speak is more difficult than on my other trombones, which all have some type of rotary valve. It's one of the aluminum core examples, so eventually it will need to be replaced, and I'm torn on whether to have a new design axial installed, or to go to a standard rotary.
I'd probably swap it out for an infinity; worst case scenario, you can probably sell that valve section and use the funds to replace with a rotary. If you go rotary right away, you won't be able to use most of that tubing anyway, including the neckpipe because of the different dimensions of the Thayer vs. whatever rotary you'd use... and you're likely to find a new thayer that is sealed well goes a long way. (Just replacing the thayer is going to be a lot cheaper and possibly sufficient.)
brassmedic
Posts: 181
Joined: Fri Dec 14, 2018 12:07 pm
Contact:

Re: Rotary valves: Open Port Vs. Closed Port

Post by brassmedic » Fri Nov 01, 2019 1:45 am

tbonesullivan wrote:
Thu Oct 31, 2019 8:30 am
It's one of the aluminum core examples, so eventually it will need to be replaced
I am puzzled by this statement. What does having an aluminum core have to do with whether or not it needs to be replaced?
Brad Close Brass Instruments - brassmedic.com
User avatar
BGuttman
Posts: 1607
Joined: Thu Mar 22, 2018 7:19 am
Location: Cow Hampshire

Re: Rotary valves: Open Port Vs. Closed Port

Post by BGuttman » Fri Nov 01, 2019 7:13 am

brassmedic wrote:
Fri Nov 01, 2019 1:45 am
tbonesullivan wrote:
Thu Oct 31, 2019 8:30 am
It's one of the aluminum core examples, so eventually it will need to be replaced
I am puzzled by this statement. What does having an aluminum core have to do with whether or not it needs to be replaced?
I think it might be because some of the early aluminum cores were not treated and would corrode. I know Shires played with anodizing aluminum cores when they experimented with making their own Axial. That would slow down the degradation, but I think they ran into some sizing problems.

I wonder if a soft metal like aluminum changes the sound you get. I've never played an axial of any sort so I can't comment on that.
Bruce Guttman
Merrimack Valley Philharmonic Orchestra
"Almost Professional"
tbonesullivan
Posts: 226
Joined: Tue Jul 02, 2019 9:06 am
Location: New Jersey
Contact:

Re: Rotary valves: Open Port Vs. Closed Port

Post by tbonesullivan » Fri Nov 01, 2019 7:38 am

brassmedic wrote:
Fri Nov 01, 2019 1:45 am
tbonesullivan wrote:
Thu Oct 31, 2019 8:30 am
It's one of the aluminum core examples, so eventually it will need to be replaced
I am puzzled by this statement. What does having an aluminum core have to do with whether or not it needs to be replaced?
I have Bach 42T with valve serial 0064, with an Orla Ed Thayer marked valve. The core is grayish, and I believe teflon coated. The core coating has abraded in several areas, which has resulted in oxidation, and I have been told it will spread. I've been told it would probably be better when that happens to just replace the whole valve.

Also, the the back plate for the aluminum valves has no replaceable spindle bearing, like an Edwards or Shires valve does. So, once that wears, there's really no choice.
David S. - daveyboy37 from TTF
Bach 39 Alto, King 2103 / 3b, Yamaha YSL-640, Bach 42T, Kanstul 1570CR, Kanstul 1588CR, Yamaha YBL-612 RII, Sterling Perantucci 1056GH Euphonium, Yamaha YBB-631S Tuba
Livingston Symphony Orchestra NJ - Trombone
tbonesullivan
Posts: 226
Joined: Tue Jul 02, 2019 9:06 am
Location: New Jersey
Contact:

Re: Rotary valves: Open Port Vs. Closed Port

Post by tbonesullivan » Fri Nov 01, 2019 7:42 am

BGuttman wrote:
Fri Nov 01, 2019 7:13 am
I think it might be because some of the early aluminum cores were not treated and would corrode. I know Shires played with anodizing aluminum cores when they experimented with making their own Axial. That would slow down the degradation, but I think they ran into some sizing problems.

I wonder if a soft metal like aluminum changes the sound you get. I've never played an axial of any sort so I can't comment on that.
Yes, it corrodes. The early version of the Aluminum cores were at least partly cast, and then coated with some type of teflon. The surface is somewhat matte. These were later replaced with fully machined and anodized cores, which should be far more resilient to wear and corrosion.

The valve core material is going to make a difference, regardless of what it is. I have always liked the sound of the instrument, even when it had excessive end play, because when Bach originally made it, they did not know how to properly fit the thayer valves. Which is why I've had to have it worked on. Twice.
David S. - daveyboy37 from TTF
Bach 39 Alto, King 2103 / 3b, Yamaha YSL-640, Bach 42T, Kanstul 1570CR, Kanstul 1588CR, Yamaha YBL-612 RII, Sterling Perantucci 1056GH Euphonium, Yamaha YBB-631S Tuba
Livingston Symphony Orchestra NJ - Trombone
Post Reply

Return to “Modification & Repair”