Valve rotated 180 degrees

[MaryAnn]

Well, I took the valve caps off because the 4th valve was clanking a little, and valve #4 is 180 degrees off in terms of the alignment marks. So can the people who work on these things explain a) is this a problem, and b) if so do I need to fix it somehow. The marks, instead of being at 3 o'clock and 6 o'clock, are at 9 and 12.

[Jim Brewer]

Has the rear bearing cap been removed at any time and put on 180 degrees off?

[MaryAnn]

I have no idea. The tuba is new to me. the mark that is "fixed in place" is in the same place as the fixed mark on the other valves, at 6 oclock. It is only the marks that rotate when you operate the valve, that are off 180 degrees compared to the other valve I looked at, whose marks lined up as expected.

There are also what I will call "hash marks" on the valves, the number of "hashes" being the same as the valve number. So the four "hash marks" line up exactly as well as the three hashes on valve #3.

[MaryAnn]

I can't find any vertical play. I haven't messed with the screws but will. One of the quieter valves has more vertical play than this one. I was wondering if the bumpers could have anything to do with it. I've never, ever, in 15 years had to mess with the rotary valves on my horn, so I know zilch about them.

[MaryAnn]

It was the center screw, which needed about 1/16 of a turn. Thank you! A couple others were not quite tight so they got fixed at the same time. Learned something today.

[MaryAnn]

Ah but. All the valves are vented; it seems having it 180 out makes the vent not working. True? Unless of course it was vented in the 180 position. It sounds like I'm going to have to have my tuba repair friend take it apart and see what he sees. Next time I see him.

[MaryAnn]

TY I'll check that. Duh.

Yeah I can hear the hiss. All is well and I'm now going to just forget about the valves until something actually goes wrong, then I'll have that 4th one turned around and put right.

[MaryAnn]

Well ok, my friend who has the other NStar says it has a conical valve section. So 180 degrees off could "theoretically" have mis-matched ports, size-wise. It does not seem likely to me that the valve itself has a taper. That would be going a bit far during manufacturing. So I would guess that maybe tubing between valves has a taper, but not the valves themselves. Anybody?

[Rick Denney]

Well ok, my friend who has the other NStar says it has a conical valve section. So 180 degrees off could "theoretically" have mis-matched ports, size-wise. It does not seem likely to me that the valve itself has a taper. That would be going a bit far during manufacturing. So I would guess that maybe tubing between valves has a taper, but not the valves themselves. Anybody?

Correct. But are you sure it's the valve that is reversed, or is it just the rear bearing plate? Unless you actually removed the rear bearing plate, which requires driving it out with a small mallet, you can't see the rotor itself except through the ports.

The marks are usually placed to provide future alignment for the rear bearing plate, and also to remember which valve the plate goes into (they usually use one mark for the first valve, two for the second, and so on). The plate itself is machined round, so unless it was made eccentric and is binding, there is no need to correct it at all.

I seriously doubt the valve rotor is reversed. Miraphone usually uses a round stop-arm shaft with a flat cut in it that aligns the stop arm, and turning it isn't possible without also moving the stop-arm plate (which holds the bumpers). There was a fad back in the day where people did that so that the rotation for the third and fourth valve is the same as for the first and second. If you bought your Norwegian Star new, I'm sure this is not the case with yours. But you can tell if the stop arms point the same direction on all four valves, which they usually would not from the factory. In any case, you'd see this as filled holes where the stop arm screws used to be, and you would not be able to tell anything from the back with the rear dust cover removed.

Rick "a picture would really help" Denney

[Rick Denney]

many words.

Reportedly, it plays, and isn't clicking.

Joe, be nice.

Rick "who was responding to what was obviously a misunderstanding of how it works, that persisted after your explanation" Denney

[Erik_Sweden]

Hi all,

A question related to this issue:
Is the screw in the center of the valve rear just a dust cover for the spindle, or is it important how long in it is screwed ?

[imperialbari]

The milled air passages in rotor blocks cannot be conical.

No matter which direction the rotor turns, the air direction trough one of the passages will be reversed when the valve is activated.

A conical passage would be reversed conical in one of the positions.

Klaus

[MaryAnn]

Thanks Klaus. Perfect sense.

A picture would help a lot but I have not been able to figure out how to upload one. Used to be able to, now no idea. Perhaps there is somewhere already on here with directions? I'm not really fond of the idea of starting an account on somewhere like photobucket.

Oh, and it works fine. The slight noise was fixed by tightening the center screw just a tad.

Rick, no, this is not new. I don't know how old it is. The 4th valve, to me, seems just a slight bit harder to play than 1+3. I use 4th valve a lot but most people don't, so I would expect it to have less wear, not more, than the other valves. Maybe I just don't have the slides set well yet. I have a hard time telling resonance in a tuba, as opposed to a horn.

[Donn]

Used to be able to, now no idea. Perhaps there is somewhere already on here with directions?

It is simpler than it used to be. When you're typing out a post, direct your eyes below the text entry area, below the <Submit> etc. buttons, to a tab thing, <Options>/<Upload attachment>. Select that second tab, and follow directions, and it should turn out OK from there. Later in the sequence you should get a <Place inline> option on your file, use that if you want to work the image into your text narrative.

That's common storage, so of course it's even more important than always to reduce the size of your image first. Images from a typical digital camera are far larger than they need to be in a post, which could usually be something like the classic 640x480 and still serve the purpose perfectly well. I use Preview to do that (Mac OS X.)

[MaryAnn]

Test picture of cat. Will follow with picture of valve if I can get the phone to take one. Long process...take pic, go somewhere with free wifi, email to myself, download, put here. Meanwhile, enjoy the cat picture.

Puddy Tat bed feet in air cropped.jpg

[Donn]

No ... not cat pictures ...

Peppermint was in her late teens when she stopped by for a visit a couple years ago. She's now 20, still gets around and jumps up on furniture. In her earlier years in the Sierras, she was a notable squirrel hunter.

[Roger Lewis]

Hi MaryAnn.
I'd like to clear a few things up for everyone. Unless you've had the valves vented by a repair shop, the Norwegian Star does not come from the factory with vented rotors. What you are hearing is the air being sucked in around the valve bearings. If they were vented you would see a small hole drilled between the two pipes for the slides in the valve casing.

I think that the clicking noise you were hearing comes from a lack of oil on the upper and lower valve bearings. Your horn should have come with a small needle oiler that allows you to easily put a drop of oil on the upper and lower bearings. Access to the upper bearing is between the cork holder and the bottom of the stop arm. Put a drop of oil there and then, without pushing the valve down, pull the slide for that valve and the suction created will draw the oil down into the bearing itself. Do the same with the lower bearing under the screw cap on the bottom of the valve and the clicking should go away. My Piggy has a lot of miles on it but this will usually quiet them right down.

By the way having the markings 180 degrees is not a huge deal. Just use a small metal ruler to verify that the corks are not worn. One thing to note. The rotors come from the factory with neoprene on the down stroke of the valve but cork on the upstroke which will wear rather quickly and require replacement often unless you replace the cork with neoprene. Doing so will tend to increase the amount of "bounce" you may experience on the upstroke.

Give me a shout if you need more information.
All the best to you my friend.

Roger

[imperialbari]

Roger’s signature has a tremendous effect. Every time.

[MaryAnn]

I didn't buy it new. I suppose I could find the serial number? And figure out when it was made. All five valves are vented (there are five tiny holes drilled through the casings, one for each valve. All the bumpers are neoprene. #4 lines up fine at 180 degrees, but next time I have it cleaned (I DID have it ultrasounded, because something inside was making me feel not so good, and the cleaning fixed that. Maybe *that* guy put the valve in at 180? I just now thought of that.) It was the guy who put on the Joykey who said it must have been vented at the factory. That's probably because he thought I bought it new. I don't know who vented them; I am at least the third owner. Thank you, again, everyone, for all the information.