Venting rotary valve?

[djwpe]

I have vented two tubas, and, despite being VERY apprehensive, it worked out just fine. I followed instructions and took my time. The biggest pain was getting the hole started without the bit sliding around and gouging all the lacquer. Patience is your friend. Everything else went according to plan. I haven't yet vented the Hagen, but I need to bite the bullet and get it over with.

Your Hagen wasn’t factory vented? Mine was...

Don

[pjv]

One of the piston tubas I rarely use is vented at the bottom of the piston itself (not the casing). The air passes through the (hollow) valve and channels out the bottom, where it enters or exits the casing through the bottom valve cap.

[Doc]

Your Hagen wasn’t factory vented? Mine was...

Don

I assumed it would be, but no such luck .

[bloke]

Do any B-flat players pull slides...??

[jonesbrass]

One of the piston tubas I rarely use is vented at the bottom of the piston itself (not the casing). The air passes through the (hollow) valve and channels out the bottom, where it enters or exits the casing through the bottom valve cap.

From what I’ve seen, pistons are vented that way. No need to modify the casing. I’m going to get some of my pistons vented after the new year. It will really help on my 6/4 CC.

[Doc]

Do any B-flat players pull slides...??

[Rick Denney]

You can mount the drill bit in the handle for a watchmaker’s screwdriver (the kind that has replaceable bits and a rotating finger pad at the top) and drill the hole by hand very accurately, and very close to the slide tubes. This works for pistons, too.

I have cut slots in pistons using a Dremel cutoff wheel, and that works, too. I did that on my 621 F and it worked perfectly. But alignment is crucial. And worn pistons or rotors struggle enough to avoid leakage, so for those I just say no. Matt Walters vented the valves on the York Master, and Bloke vented them on the Holton. Both made a smaller hole than I would have, and smaller than the factory vent in the first valve of my Eastman.

I need to vent the first valve on my Hirsbrunner. The staff C is flat, as usual, and the first slide is (beautifully) made to be easily adjusted. But without the vent, the pops are a problem. I’ve been using the fourth valve for that note, too.

Rick “more fearful of screwing up with increased age-related wisdom” Denney

[Jperry1466]

Finally got this project done after coming down with Covid-19. Fortunately, I had a very mild case with low grade fever, loss of apetite, and extreme lethargy for 3-4 days. The aftermath was worse than the virus, getting tired easily. (I had to rest after unloading the dishwasher, for crying out loud.)

I took all the advice and pics from here to my repairman who said "never trust anything from a forum" then called Miraphone to get instructions. As you can see, the pic looks exactly like the pics that were posted here on the forum. But I like this repairman, so I kept my mouth shut. The hole isn't the neatest-looking, but it works great. The pop when moving the 1st slide is gone, and the horn plays as well as I had hoped. Another benefit was that the repairman took note of my small, arthritic hands and moved the valve spatulas closer together. I am extremely happy with the final product. Thanks, guys for all the good info.

[jonesbrass]

The pop when moving the 1st slide is gone, and the horn plays as well as I had hoped. Another benefit was that the repairman took note of my small, arthritic hands and moved the valve spatulas closer together. I am extremely happy with the final product.

Who doesn’t love a happy ending? Glad you are over the ‘rona, too.

[bloke]

As - 99% of the time - rotor casings (or - ref: Progressive Ins. Co - "Rotaur") are mounted on people's instruments, I use 12-inch-long 1/16" diameter (choose your own diameter) "aircraft" bits.

I could re-sharpen them, but I buy a gob at a time, and toss them when they stop cutting as quickly.

I did the "3 vertically-aligned holes" thing decades ago, when I installed a very long-throw 5th valve (right hand) trigger on my F-tuba - to microtune 5-6-4 "low A", and also to offer me a 5-6-1-2-3-4 2nd partial (matching timbre / easier to focus) "low F".
lucky me: Those two pitches are the only ones which involve any slide-moving on that instrument...but maybe (??) that's why others wince, when I'm playing ensemble pieces with them.

Arguments can be offered up for drilling those holes a bit off-center vertically (to get them farther away from the ports), as well as putting them a bit off-center horizontally (so that a subtle paddle-touch (prior to playing a passage) PRE-equalizes the air pressure. I'll let others (who also enjoy "lacquer vs. silver" and "globby vs. non-globby mouthpieces") argue over those preferences, but (unlike those two parenthetical topics) there might (??) actually be purposes for those off-center venting strategies...(??)

It's also a good idea to take the rotor out, because the tubing knuckles (brazed in to the rotors) are not always centered on the spacing between the knuckles...particularly not (sometimes) with jimbo.

You can get them for a couple dollars less, if you buy a package of several, but here's one that can be bought at "laagge oohange - YET 'currently out of stock'...but you'll find them elsewhere.".

https://www.homedepot.com/p/Drill-Ameri ... /305284245

[Doc]

I finally got around to venting the Hagen today. It’s only been nearly a year. Btw, the holes ARE round, but you might see some black ink around some of them where I marked the drilling location.

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[bloke]

“Hagen“ sounds like it should be the name of some creamy spread made from some exotic mixture of nuts with lots of sugar.

[Three Valves]

It will always remind me of Nina Hagen.

[grayax]

Do any B-flat players pull slides...??

Once I get done modifying and rebuilding by 1241, I probably will need to down in the pedal register (adding a fifth valve).

[gocsick]

Adding a caveat from a hard lesson learned. If you decide to do this yourself... figure out how you are going to deburr your holes.....BEFORE you start drilling. There is much less room on either side than you think.

[bloke]

If you slow down at the end, you might not have to do much deburring at all.

The easiest way to do it is to rub the inside of the hole with a drumstick mashing the burr towards the center of the hole, drilling again, and then doing both of those things (drumstick rubbing and re-drilling) one more time.
By then, probably there's no more burr and you didn't have to use some tiny deburring tool or sandpaper or any of that mess.

[Mary Ann]

Do it; it will fix your problem.

[tadawson]

Seems like it wouldn't be too hard to make a drill guide for this . . .

Considering that all rotors on most horns are the same size, I would expect that the gap between the branches is the same for all.

So, take a piece of pretty hard metal, and cut it to that width, getting larger towards the top.

This should now slip between the branches, and stop at a fixed depth where it gets wider.

Drilll guide holes in this piece where you want the vent holes.

Insert the guide between the branches, and the drill into the guide hole. Consistent placement, and the bit can't walk.

???

[gocsick]

The difficulty is that you can't get exactly the same angle on all the rotors because of different tubing and braces in the way. 2 and 4 are clear on mine and I had a nice straight short with the drill perpendicular to the surface. 3 has a brace in the way so you have to come in just a bit angled to the side and I've had tubing so you need to come in at a downward angle.

I think the guide would be nearly universal... but you would need one for each rotor and tuba

[bloke]

I've never had any trouble with that, particularly since those bits are so flexible.
again:
One hand on the drill trigger and one hand on the bit a few inches back from the drilling location.

This isn't a milling machine... It's just a hole being drilled.

Also, why do they all have to go straight in?
As long as the holes don't go to the left or to the right from center very much, there's a huge area that is acceptable for venting on the inside.

I've done a bunch of them and I know that makes a difference, but using one hand on the bit and one hand on the trigger, you can get all the holes drilled in the same spot and straight through - and without any up or down drift, either...

...or did I not read your post correctly?