The Great Kurath Re-Tubing

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bloke
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Re: The Great Kurath Re-Tubing

Post by bloke »

Stepping off into oldness, I believe my personality is changing more than I care to admit.
I received a shipment of stuff from Waldkraiburg a couple of days ago, and really couldn’t remember what was in it, until I looked. 😳
————————
My next thing is to convert/upgrade (only because it’s necessary to repair the thing) a Chinese knockoff of a Bach 42 inside slide assembly to the actual way that Bach makes them, rather than the fall-apart shortcut way that the Chinese factory made their knock-off…a way which failed, as would be expected (once most anyone saw how they did it).
By the way, this is a Chinese brand (and not a Jinbao brand) over which some people seem to be oohing and ahhing - including on this site.
In my epic collection of saved playing slide tubes, found a decent/used Bach 42 inside slide tube (that I can shorten to an upper from a lower), and obviously needed a venturi/mouthpipe - which arrived from Conn-Selmer yesterday. Somehow (??), I DID ACTUALLY remember what was going to be in that box. 👍
(I sort of hope this Chinese company decides to go ahead and upgrade their inside slide assembly, even though the Bach method and parts require more hand-work during the assembly procedure. I can see these inside slide assemblies - on these things - failing over-and-over again, and the repair of them tedious, as it requires a bit of hardware remanufacturing on the lathe.)
=============
OK… away from Chinese trombones and back to Swiss tubas !!!
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the elephant (Thu Jan 20, 2022 11:33 am)


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Re: The Great Kurath Re-Tubing

Post by the elephant »

Today I hiked up and down my mountain of old horns to locate some parts I need for this tuba.

I have a 1930s-era "Carl Fischer"-stenciled French horn from Italy that has pretty much a negative value (meaning I would have to pay someone to take it off my hands) that I am willing to cannibalize. So I plan on rehabbing the levers and lever rack and then modifying it to use as my 5th/6th finger paddle set.

I need to replace the badly worn steel drill rod used as the lever axle with one that is a bit thicker. This will allow me to drill out the badly worn hinge tubes so that the tolerances are correct. (These levers currently have all sorts of slop between the axle and the hinge tubes, so this will be an improvement.) This will take some time to do well.

I also need to shorten the rack from three to two levers, which won't be hard at all.

After that, I can start looking at how and where to attach the assembly to the tuba. I have the location, but some stuff will have to be fabricated to make a place on the horn for these to live.

Photos coming soon.
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Re: The Great Kurath Re-Tubing

Post by the elephant »

Boy, am I a dope.

There is nothing wrong with that set of parts. The slop is just fine.

AND…

Despite having some very silver-colored bits on the levers, most of the metal was yellow/red/brown — i.e. tarnished yellow brass. I know I'm a goob for nickel silver, but it is a lot stronger as a wear surface and is used in the nuclear and shipping industries for a reason. (They call it white copper.) It is just a better metal for binding yellow brass together. Ferrules, outer slide tubes, bow guards, backing plates for strap hooks, and thumb rings all take more of a beating than the yellow brass runners, branches, and the bell. that is why they use the stuff. It also is so much harder than yellow brass that it is more difficult/time consuming/$$$$ to draw, bend, or machine than plain yellow brass. (Even with trace amounts of lead it still is a harder material.) Add to that the fact that it currently costs almost exactly double that of yellow brass by weight and you can see why it is only rarely used as the main building material. That cost is also why lower-specced horns of the same model cost more as you add more nickel silver; increased materials cost and labor time must be passed on to the customer or they make less money for the expensive tubas than they do from the cheaper ones.

So, I was grousing yesterday after I located a seemingly suitable set of French horn levers of a design and size that will work on this project, but that they were cheap, nickel-plated brass, and most of the plating was worn away. This means the levers would be "bendy" and I would have to do a lot of sanding to get all the plating off. I would much rather have the metal be whatever it is than to have any sort of plating. I do not like anything on the surface of the horn other than the bare metal; no lacquer, no plating, no paint, no caca, no nothing.

I LOVE silver plate, but when it finally starts coming off it makes the horn look (to ME) really cheap and — well, I guess the word "fake" is what I want, though it does not really work here. You get my drift, I am sure. I know others feel very differently about this stuff. Great. You guys build YOUR tubas the way you want them to look. I will continue to pick those nits* and take my time to make things look as much like I see them in my mind.

Okay, so that jumbo "and" up above means that once I started to cut these parts to the needed configuration I noted that they are not yellow inside, under that plating. The levers and rack are solid nickel silver.

:bugeyes: :facepalm2:

I have never seen this stuff turn BROWN like this, so it must have lost its lacquer and then over the many years since was exposed to some caustic stuff to turn like that. Whatever, I was delighted that my undersized, flimsy levers and paddle rack are not flimsy at all, and now that I have cut them to spec I find that they are also not undersized by all that much. I would rather have tuba paddles/platens, but they will not fit the space. (I have a set from a Jinbao 410 and there is no way they would work… and they *are* cheap, bendable brass plated thinly with nickel.)

So this worked out perfectly!

_________________
* If you're old enough or you read a lot of old literature you will know the correct meaning of nitpicking. If you don't and the dictionary is too much of a reach for you then don't worry about it. ;-)

And now for some good, old Horn Porn…

Forgive my misidentifying this as brass with ruined nickel plating, but you can see how one might think that…
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Bottom of the rack but top of the levers. (I had the springs fitted, so that is the unsprung position. Sorry. I'm sure you'll survive your crushing disappointment. ;-)
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And the reverse. These parts cleaned up "right nicely". I won't cut the axle rod until I have a suitable nut for the end.
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These had a really odd feature I have never come across before. The springs had to be wound while on the levers. The wire was centered in the holes of the levers and then bent around them and spiral wound onto both ends of the hinge tube, then the ends were nicely wound to keep them from having those nasty finger pokers on the ends. Weird. I hated cutting them off, but it was the only way short of completely unwinding one end and pulling the wire through the eyelet.
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The hinge rod/axle end nut was cut off and peened over a little so that removal would take a Dremel and some careful work. I like the way it came out, though — sort of a two-tone look.
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This is how my hand will have to lay next to this assembly, so I have to dink around with the levers, bending them until I find what works best. For now, they look like this.
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Here are the three levers, together one last time before I consign the brown one to my Oddball Parts bin. I really did think these were brass with destroyed plating. I am glad I was wrong.
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The dealio sounds good to me, Uncle Rico.
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Re: The Great Kurath Re-Tubing

Post by the elephant »

Despite its apparent awkwardness, after having considered about a dozen other possible layouts for the valves and linkages both, this is what I am going to try to build.

At least the first time. I usually make many changes to scratch projects like this on the fly, but I am getting better at seeing the pitfalls before I start the work. I usually have an idea in my head and just start making stuff, but I am planning this one out a lot more as I am using some expensive parts. Unlike the Mirafone 186, I am adding a valve that does not have a proven, safe location with a known setup and pre-made parts available to purchase. This one is surely wining it, and the results might just suck.

Anyway, this is the setup that I think might work out well. The two linkage rods will have to cross one another, so I have to work that out. Also, as drawn, the 6th valve (the upper one) will be very difficult to route the linkage to. I was considering a completely different setup when I ordered my custom valve. And now that valve may not work out for me unless I do some Rube Goldberg stuff.

We shall see.

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Re: The Great Kurath Re-Tubing

Post by bloke »

Being an old fart - as well as having a much older brother who played an unplated-nickel-silver-keys clarinet in the 1950s, I first saw that color over sixty years ago… though I was just a (very) little turd, I did notice that places where he touched were silvery, and places that he didn’t touch were yellowish.
… and my F tuba (which I never chemically stripped, but featured gorgeous micron-thin rattle-can-quality lacquer on it…for a few months - when it was new 🙄) has a good bit of that color on it as well.
First silvery, then yellow, then brown.

Around 1970, my brother brought back a very fancy chess set from Thailand made of that stuff. Though I didn’t immediately relate it to his clarinet keys, he made a point of educating me about the metal and the things that go into those alloys. He asked that no one touch it with their hands, it turned a gorgeous tone of gold, and stayed that way for quite a long time. (His colonel at Fort Campbell pulled some strings and got him sent there - rather than Vietnam, because he was drafted in his mid-20s, the colonel realized how smart he was - just as I do - and my brother had a masters degree in psychology. There was actually a psychology-related job in Thailand that needed filling, which involved creating textbooks and using them to train soldiers to not be a$$h0le$ around/to the Thai people.

I’m really bad about going off on a tangent, but also I’m coming off of anesthesia, so I will use that as an excuse this time…

…and hey: I MOSTLY spoke to the topic of “different ways that nickel silver tarnishes”…no?

(I’m glad that you have what you need already. When we spoke privately – and you were still thinking they were brass, I was scratching my head somewhat.)
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the elephant (Mon Jan 24, 2022 8:09 pm)
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Re: The Great Kurath Re-Tubing

Post by the elephant »

All of my horns have had lots of unlacquered nickel silver and have never turned anything other than gray, even after decades of not being polished or cleaned. Never seen it turn brown ever, not even once.

Skin chemistry is funny stuff…
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Re: The Great Kurath Re-Tubing

Post by LargeTuba »

@bloke did you ever finish putting a 6th valve on your tenor tuba? It seemed like it would be in basically the same spot that Mr. Elephant is putting his.
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Re: The Great Kurath Re-Tubing

Post by bloke »

I have all the parts, but I’m trying to get other peoples things fixed up.
LargeTuba wrote: Tue Jan 25, 2022 2:29 pm @bloke did you ever finish putting a 6th valve on your tenor tuba? It seemed like it would be in basically the same spot that Mr. Elephant is putting his.
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Re: The Great Kurath Re-Tubing

Post by the elephant »

Speaking of parts and added 6th valves, this arrived only an hour ago.

This order contains the two valves and all the crooks and runners to build out my new 5th/6th valve section, as well as a needed bottom cap for another valve, and 24 5.00 mm nickel silver adjustable brace feet. [I picked up five 250 mm X 5 mm nickel silver rods for a song from Howarth Woodwinds of London. They have a lot of cutoffs that are too short for their machines to grip. They use a lot of different diameters for oboe, bassoon, etc. keys. While these cutoffs are unused, they are unusable for them, so they sell them dirt cheap on eBay as used nickel rod stock. I picked up all this rod stock for like $20 shipped from England! I am still waiting for this packet of rods to arrive, though.]

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Here are the new 5th and 6th valves for this Kurath. The one on the right is a Model 86 valve (19.54 mm) with knuckles and cork plate oriented the way I requested, and the knuckle connecting to the valve on the left @ 20.35 mm. The valve on the left is a normal 1st valve for the Model 291 @ 20.35 mm through all four knuckles.

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Re: The Great Kurath Re-Tubing

Post by the elephant »

We have a huge Star Wars program this weekend and the first of the two rehearsals is tonight. I have to practice for an hour or two and then rest, so I am done dinking around in the laundry room for today.

I spent like two hours reorganizing and putting stuff away. That was cathartic AF, let me tell you.

Then I got to these two new valves. The custom one's larger port was still a bit smaller than those on the larger valve. I had to carefully expand that knuckle so that it would fit the ferrule tubing that will connect it to the other valve.

The other valve (set up as a 1st for a 291 "Bruckner") had four squished knuckle ends that had not been deburred. (Someone must have gone to lunch and then forgot these last two steps when he got back to work. It happens…) So I spent some time with my expander, a dent hammer, and short lengths of the adjacent sized tubes. I used the expander to gently round the knuckles enough to get the smaller tube inside to sort of force it into shape enough to tap on it to reduce the stress when it is closer to being round. Then I put the outer tube on over the inner and the knuckle. I inserted the same sized tube so that I had a three-tube sandwich that was stout enough to hammer on a little more aggressively. After that, I used the expander to make sure the tubes were as round as I could get them and fit the outer ferrule material fairly snug. It has to be tight enough to not fall off, but it needs to stay where I put it when soldering stuff together.

So now all eight knuckle ends are in good shape. I like these valves, too. I also did some preliminary measuring and marking of the 6th slide parts and will likely cut and clean them tomorrow. I would like to have all the parts for the 6th unit ready to dry-fit before I have to shower and get ready for rehearsal tomorrow evening. If things go well, maybe I can also have the slide aligned and assembled.

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Re: The Great Kurath Re-Tubing

Post by the elephant »

Today I measured out the "fixed size" parts of my 6th valve slide circuit design and deducted that from the overall length that I have decided to make this loop (which is 11.5") to give me the following:

crook - 2.5"
"up" knuckle - 0.5"
"out" knuckle + elbow - 2.5"

That leaves me with 6" for inner slide legs, and they will be the same size, so I need to cut a pair of inner and outer legs of 3" each, and that leaves me with three connecting ferrules that will have to be very short.

So here is the custom rotor, three ferrules, the trimmed crook, the homemade elbow (in all its inelegant glory), and the slide leg sets, all assembled quite nicely. I like it. I think it will be an interesting addition to my F tuba.

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Re: The Great Kurath Re-Tubing

Post by the elephant »

Today I cut all the parts needed for the new 5th slide circuit. The missing parts are the one three-piece brace, which I measured and cut but failed to get into the pic (D'OH!), and the inner/outer slide leg sets, which are currently on the tuba.

Included here are the two 90º elbows, two crooks, two 15 mm and two 10 mm ferrules.

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Tomorrow I will remove the 5th valve section from the rest of the machine and start lining up the 6th valve to the bugle. Once that is soldered in place I can take apart the old 5th slide and steal my slide legs (only a few months old) and build my new 5th circuit. I will leave it loose at the two elbows so that I can rotate the slide on the valve. This will allow me to clock the valve so that the slide legs are centered over the bottom valve caps, right to left. Once the valve is on at the correct clock location I can then make the slide loop "flat" (perpendicular) to the pistons and solder the two elbows to the slide legs.

Then bracing can begin.

I will set up the 5th with the current lever and linkage, though I hate the location, and get it working as a five-banger. I will lock 6th in place so that it cannot b accidentally rotated while I am playing.

Then I can start looking at installing the 5th/6th French horn levers. Once that is done I first have to figure out how to hook up the existing thumb lever AND the left index finger lever so that you can use either. Once that is done I can figure out the PITA 6th linkage.

I may have painted myself into a corner with this one…
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bloke (Sun Feb 20, 2022 8:29 pm)
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Re: The Great Kurath Re-Tubing

Post by bloke »

You tube.
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Re: The Great Kurath Re-Tubing

Post by the elephant »

I was thinking of trying out the time-lapse feature on my phone and using a tripod to film the assembly. I have had people ask me for videos and I hate narrating them. I refuse to write out a script, so I just extemporize and make sh¡t up as I go. I always enjoy well-shot time-lapse videos of mechanical processes. I could put on some of that horrible, royalty-free YouTube music in the background and mug at the camera every five or six minutes. Might be fun.

Seriously, though, videos are much better, but I am not comfortable making them. I need to decide what I want to do and then do it. If I opt for more videos so as to not clutter these threads with a bunch of photos and my alphabetic gibberish. I don't need to buy anything as I have no intention of being a "YouTuber" with pro-level equipment paid for by viewer donations. I don't really have any viewers. I think I have like 45 subscribers (if that many). But time-lapse or close-up video clips with me overdubbing a scripted, concise write-up would make these threads much more "compact". And fewer words to read would appeal to the fans of Waffle House pictograph menus. "Gimme wunna dem der patty merts witta Co-Colar."
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Re: The Great Kurath Re-Tubing

Post by Schlitzz »

the elephant wrote: Sun Feb 20, 2022 9:03 pm I refuse to write out a script, so I just extemporize and make sh¡t up as I go.

Oh, you've heard of the viola solo cadenza?
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Re: The Great Kurath Re-Tubing

Post by bloke »

That’s all really great, but I only meant it as a simple sentence - with a subject and a verb - rather than a suggestion. 😉
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Re: The Great Kurath Re-Tubing

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bloke wrote: Sun Feb 20, 2022 11:45 pm That’s all really great, but I only meant it as a simple sentence - with a subject and a verb - rather than a suggestion. 😉
That went right over my head. Sorry, I don't understand.
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bloke (Mon Feb 21, 2022 12:00 am)
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Re: The Great Kurath Re-Tubing

Post by bloke »

It’s just a silly pun.
“Tube” is the same verb (implied verb) that you use in the title of this thread.
It’s such a very stupid joke, that you are trying to look at ground level and above for the humor in it, thus missing it - due to its “below see-level” idiocy.
I’m looking forward to seeing it put together; it looks pretty wild. I’ve often stared at piston F tubas, and wondered (as with this one – without completely starting over) if they could somehow be set up with a 4+2 configuration. All I could come up with in my mind has been Rube Goldberg rigging, and maybe that’s just what’s required…(??)
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Re: The Great Kurath Re-Tubing

Post by the elephant »

Ah, yes, indeed. I tube.

Sorry, I did not see the space between the two words and read "YouTube", supposing that you were telling me to post a video of what I had mentioned in the above post.

Sorry.

And I am in agreement with you that Mr. Goldberg would have had fun drawing one of his famed illustrations based on whatever it is that I come up with.

I will likely need a supply of wire hangers to model the long, oddly shaped 6th linkage. I bet I could find a goodly supply of them for free at the old Joan Crawford estate. Oh, wait, was that insensitive? It certainly wasn't very inclusive. Sorry. Someone, please report me to the authorities.

Yeah, it has been one of *those* mornings…

:coffee:

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Re: The Great Kurath Re-Tubing

Post by bloke »

Coat hangers trigger me, as do all feminophobic symbols. :slap:
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