Kurath — Am I Finallyl Finished?

Projects, repair topics, and Frankentubas
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bloke
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Re: Kurath — Am I Finallyl Finished?

Post by bloke »

Your 6-valve (will be short-lived) F unfamiliarity is similar to my (likely, never-will-quite-be-overcome) 5-valve+trigger F unfamiliarity.
When I encounter divergent valve combinations (B with 2-4 + 2nd slide trigger, range just above low F - with low G certainly requiring the 2nd slide trigger, etc...) playing the F cimbasso, I'll still occasionally write in the damned fingerings (along with a "T"). If such pitches are required over-and-over...no, I don't need to do that (ex: Verdi's Va, pensiero chorus from Nabucco...is that ten - or is it fifteen sharps, in the key signature...??), but when "licks" occur once or twice - which encounter those pitches, yeah...I might write the fingerings in...particularly if they are syncopated "rock" or "jazz" licks (where I'm both concentrating on timing and fingerings).
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the elephant (Mon Dec 23, 2024 12:48 pm)


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Re: Kurath — Am I Finallyl Finished?

Post by the elephant »

I'll be performing the Broughton on this tuba on April 27th. Free admission.

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Re: Kurath — Am I Finallyl Finished?

Post by MiBrassFS »

That’s a great picture! Framed poster worthy, for sure.
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Re: Kurath — Am I Finallyl Finished?

Post by arpthark »

Great poster! Yamayork makes a pretty good background.

Good thing to have the rolled up sheet music at the ready, ya know, to ward off unwanted flies during the photo shoot…
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Re: Kurath — Am I Finallyl Finished?

Post by the elephant »

I have this disturbing Frasier Crane vibe going.

Just shoot me now.
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Re: Kurath — Am I Finallyl Finished?

Post by bloke »

I just shot E.M. a message telling him to find him or us any sort of an excuse for any sort of gig that pays anything at all so that I can tell Mrs bloke I need to go down there that weekend.
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the elephant (Fri Apr 04, 2025 5:55 pm)
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Re: Kurath — Am I Finallyl Finished?

Post by the elephant »

After finally getting to give the 5th/6th valve system a good bit of use, I have decided that I need to unwrap one side of the lever springs one wrap to reduce the tension, which is way too strong for me to have any sort of technical facility down there.

Tomorrow.

Also, the upper 3rd slide needs a half-inch haircut to bring it up to pitch.

Later, but soon.

And I am beginning to believe that my 5th and 6th slides are finally settled in where they need to be, and I can take stuff apart and replace the legs with sets of the correct length. I will, at that time, realign the to rotors to allow the slides to fit in their space somewhat better and shorten an overlong brace, which will strengthen it a bit.

Also, I think I will make a new mute out of sheet aluminum that is a copy of my Ion Balu mute. It works well but is not buzzy at all, and I need buzzy, loud mutes for all my horns. If I do this and it works, I will turn the Balu mute into a practice mute. Or at least I'll try to do that. Practice mutes all pretty much suck, so whatever I come up with ought to be at least as good as anything on the market. The bar for practice mutes is set very low.

Finally, I have decided to remake the lever rack and baseplate. I will do this in the summer months. I just ordered a 125" thick 5"x10" nickel silver plate to cut up for this. I used a .125" 1.5"x10" bar to make what I have, and it was too narrow to put the lever rack far enough away from my hand rest to not have my fingers bunched up. What I have is too close to my palm for good technique. I will also use old Miraphone levers as they are just better than mine. The ones I made are very good, but the geometry is weird. (Too short, maybe?) I have ideas about what I need, and I will hack them out of that sheet of nickel silver in a few months.

So before the concerto I will adjust the spring tensions and trim the one slide. If I get around to it I will lengthen the inner legs of the 5th and 6th slides and see how I feel about them. If that is my final decision then I'll tear apart the valve section and install the outer legs to match.

Film at eleven! (That's a lie. There will be no film.)
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York-aholic (Fri Apr 04, 2025 11:24 pm)
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Re: Kurath — Am I Finallyl Finished?

Post by prairieboy1 »

Thanks for posting! That is a terrific photograph of you! :clap: :clap: :clap: :tuba:
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the elephant (Sat Apr 05, 2025 9:56 am)
1916 Holton "Mammoth" 3 valve BBb Upright Bell Tuba
1935 King "Symphony" Bass 3 valve BBb Tuba
1998 King "2341" 4 valve BBb Tuba
1970 Yamaha "321" 4 valve BBb Tuba (Yard Goat)
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Re: Kurath — Am I Finallyl Finished?

Post by the elephant »

My longtime friend and colleague is the conductor of this group, and he needs a current Bio for the program. I sent him this. (Yes, I'll send him a *real* bio later tonight.)
some loud-mouth wrote:Wade Rackley, a native of the Tamms Federal Correctional Center, was born in a log cabin he helped his father build. He never knew his mother, who left his father before he was born. Wade is a terrible person who is guilty of many felonies. Wade was the governor of South Dakota at some time in the past, under an assumed name. (No one noticed.) Wade appears courtesy of Gold’s Gym and Red Bull Energy Drink because he is such a BAMF. Today’s performance is sponsored by a big-ass grant from Swanson Hungry Man Frozen Dinners.
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Re: Kurath — Am I Finallyl Finished?

Post by the elephant »

It always pays to be curious and unsatisfied!

I worked on the springs of the levers for two hours last night. I thought I was going to ease the binding and tension of the 6th spring, and it ended up being SPRINGFEST-2025, which netted some excellent results.

First, I tried to remove the two levers and noted that the hinge rod/axle needed pliers to pull it out. No bueno.

Then I spun both levers on the rid and discovered that while the 5th spring was binding heavily against the lever rack, the 5th lever was simply not turning with a flip. With a backlight and some magnifying specs, I could find NOTHING. No schmutz. No particulate. No burrs.

<grumble>

So the next step was to whip out the super accurate mini drill press. This thing cost me next to nothing. It has no real guts for drilling, but it is perfect for shallow holes or opening up or cleaning out long holes, like short lengths of hinge rod. My big drill press has terrible runout in the quill, which is not a removable part on my cheap, Chinese unit. I junked it. This little baby is much more useful to me and has a very good Jacobs chick (made in Connecticut in the 1960s) that I restored myself. It features a fantastic .001" of runout. The Chinese unit has .011" of runout at the quill, so even a theoretically perfect chuck would still see all .011" of that runout, which is HORRIBLE. Introducing an average eBauy chuck to this would net you so much runout that you could see it from about ten feet away!

So I "reamed" the lever, and there was a tiny steel bur that had somehow gotten in there and then had been embedded into the softer hinge tube. (The rod is HSS drill rod.) I got the tube all cleaned up without opening up the hole, so the action has been returned, and the fit is the same.

Then I spent a long time uncoiling the ancient nickel silver wire springs, which are very stiff. I ended up having to unwrap about 2.5" of wire from each side of each spring, so TEN INCHES of wire was cut out…

… AND THEY ARE STILL VERY STIFF SPRINGS!!!

I guess I need to remove one more loop? Ugh.

But I suddenly have "technique" in the pedal register of the Kurath.

Cool.

That took so long that the intended slide trimmings did not happen.

Maybe today.
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Re: Kurath — Am I Finallyl Finished?

Post by bloke »

Yesterday, I spent 800 bucks on a proprietary double pulley for that ridiculous mower that you've seen, and I wasted 30 minutes on the way home at Home Depot looking for some common hardware for bifold doors that they did not have.

...so you did a lot better than I did.
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the elephant (Sun Apr 06, 2025 2:35 pm)
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Re: Kurath — Am I Finallyl Finished?

Post by the elephant »

Again: no photos. There isn't anything to photograph during these steps.

Anyway, sorry for the length, but you know how I am…
_______________

Tonight, I decided that I will indeed take off one more loop from the lever springs. Great: something sorted!

Also, to avoid doing any work that might waste expensive material and valuable time, I dry-fit some bits to extend the overly-short 6th outer tubes so I could pull out beyond the edge of them.

BINGO! Low B (46) is solid, fat, and happy now. Low A, Ab, G, and Gb are likewise happier, and the low Bb and C are ecstatic because to get all those in tune, I had to pull 5th to compensate for my too-short 6th, making Bb (45) flat, causing me to have to push in on 4th, making low C (4) in tune, but somewhat less than centered.

All that is fixed now.

With this last bit sorted, the low register on this tuba is rockin' along far better than any Willson or Kurath of this design that *I* have ever encountered. I am quite excited about this. The tuba was really good when I got it, but the low Bb was barky, pinched, and difficult to center, and moving the slide did nothing to the pitch.

The issue was that the factory "mathematically correct" slide was way too short. Likewise, my 6th was cut to what is suggested by Art's spreadsheet and backed up with my own math. It, too, was short. [Once you get these oddball valve circuits sorted, things get exciting. I can play out of the Snedecor "Low Etudes for Tuba" with the same ease and facility as with my CC tubas.]

Tomorrow I plan to cut a new set of 6th slide legs. I have a problem, though. I've run out of the tubing needed for the outer slide tubes. I have more than enough of the inner material, but only enough for one outer leg and the needed ferrules.

However, I have some MW telescoping stuff that is not exactly the same size, but is *very* close, so I think I will fudge a bit and make one leg (inner/outer/ferrule) from the same Miraphone stock that is on there now, and the other set of parts from this MW stuff. It is too large for the crook and runner ends by .25mm, meaning a slightly loose fit. I can EASILY bump up the crook and runner to fit nicely, so no issues. My problem is that I detest mismatched tubing sets.

I can always swap them out later.

I guess.
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Re: Kurath — Am I Finallyl Finished?

Post by the elephant »

I decided to leave the 6th slide as it is for now (slide, two loose spacers, two loose ferrules) to test it out at work tonight. I have the Rachmaninoff Piano Concerto No. 3 — the big one — which has an easy tuba part with a lot of low Bs and As that will allow me to fool around with this setup in the ensemble before committing with the torch and solder.

More later…
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York-aholic (Mon Apr 07, 2025 4:30 pm) • bloke (Mon Apr 07, 2025 10:53 pm)
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Re: Kurath — Am I Finallyl Finished?

Post by the elephant »

My big-a$$ nickel silver plate arrived today from Jantz, so I can finally remake my lever base plate so that the levers are in a little better location. I have been buying from them for years now, and they only ever offer 1/8" thick metal bar stock or plate in sizes that will net me a part that is a compromise of what I want and what the part can yield, or I have to buy more than I could ever use. No in-between. So now I have a lifetime supply of 1/8" thick nickel silver.

Luckily, I think I will be making something like this lever system for the Holton, so I will probably use up a lot of this in the end.

By the way… this sheet of metal is surprisingly heavy. I mean, dang…

Also, I used the Kurath today in the quintet and on Monday and Tuesday in the orchestra. 6th is nails, baby. Nails. Playing the transcription of the Holst 2nd Suite in F that we use was a lot of fun. After the trombone plays the euph solo, the tuba part is solid half notes below the staff in the tricky area, and every low Bb, A, G, and F sounded full and in tune, speaking without slowness or "flarpicity".

And at this point in the post, a whole dissertation's worth of my hairbrained ideas on this tuba were typed, edited, retyped, reedited, and — finally — deleted.

And for that, you're welcome.

:smilie8:
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Re: Kurath — Am I Finallyl Finished?

Post by the elephant »

Okay, so my cheapo, lightweight link arms on 5th and 6th are a design that works well enough when the length needed for something like a 186, but these 12"+ links do not work. Well, not exactly…

The original 5th linkage was a 6mm (c. .25") yellow brass rod with large Schaublin "Unibal" end links. Very heavy, but only about nine inches long. Solid as you would expect from this maker.

I had issues with my original, funky 5th lever — its length and shape caused it to flex all over the place. It was expensive as I wasted a lot of nickel silver rod stock sorting this problem.

I switched to some machinable, bendable stainless steel rods. They bent well enough, but once bent, they were work hardened enough that you could not unbend (adjust) them. To make my ideas come to life, the shapes kept getting ever more complex, and I would end up snapping these steel rods on tight bends. It was frustrating.

First, I ordered new, custom-made valves that simplified linkage routing greatly, and second, I switched back to nickel silver rods. In the end, the new balves allowed me to go back to (thankfully) STRAIGHT rods, so the material no longer mattered that much. Because they had to be more than a foot long, though, they were very heavy, making valve action pretty sluggish. So I opted for some super-lightweight rods. For 6th I used drill rod inside some very thin brass tubing, which worked really well, but is rather noodly feeling as it flexes visibly when used. For 5th I discovered that I no longer had enough of the drill rod, but I had some 12" lengths of 4-40 all-thread. So I used the same thin-walled brass tube (we're talking paper-thin) and ended up with some good link arms. But the all-thread is only about 2/3 the weight and thickness of the drill rod, so it is VERY flexy, and the threads would buzz and rattle against the wall of the brass outer tube.

My solution was to fill the tube with blue thread locker and run the all-thread into it while it was wet. It worked great.

Then the other day I had to remove that link arm and it flexed hard while I was snapping the sockets off the balls. Now it buzzes like a 1970s Panasonic clock radio alarm while I play. bzzzzzzzbzzzzzzbzzbzbzzzzzbzzbzzbzbzzzzzzbzzbzbzzzzzz…

It is driving me nuts, man.

so I decided to see if I could locate drill rod locally, had little to no luck, and do not really trust the stuff at Home Depot. So I am back to nickel silver. I have two rods of equal weight that are light enough, so rather thin, but usable. I will have to machine the ends and thread them in the lathe as they are to big to thread directly and too small to center drill and tap for threaded inserts. I will have to turn down the ends and run them through a die.

Only issue: Both are about an inch too short.

Sheesh.

So I may keep the drill rod arm and ditch the outer sleeve, and then make a temporary arm from the HD steel rod to replace the all-thread arm, which will likely be overly soft, prone to rust, and irradiated or toxic crap from China, and hope for the best until after the 27th, or I can maybe figure out something else. But what I have right now must be replaced ASAP.

Here is what I have. The brass rod is a eggshell-thin brass tube with smooth drill rod inside. The other is all-thread with the same outer tube (not present in the photo, of course). The threading makes the all-thread very bendy and weak, which is why the brass tube is there: stiffness, but it does not work on something this long.
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Better videw of the two rods when fully assembled.
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Also, I have removed about three wraps from each spring coil to make this suer-stiff nickel silver wire a bit more forgiving to my weaker, untrained left hand. I have discovered that using these in the Broughton is really tiring my hand out. I need to do such work more often. I have never used my left hand for valves, and it really shows after a four hour practice day. OUCH!
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