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Oh, and I have had several requests from "a-mechanical" friends to explain some of the stuff I have been doing because they do not understand the terms and tools I use. (Mostly these are old HS friends who are not musicians and who have never really learned to use tools to fix things; they throw stuff out and buy new, which I make fun of all the time.)

I have had several of them ask me to explain how you can "take two parts and make them screw together" (thread cutting). I made a three-part video of me tapping some holes and showing the entire process, which makes for some very dull viewing, but they were satisfied. I guess.

This is a screenshot from one of the three videos. I am sharing it because it is really beautiful to me. I know it is just a photo of a bolt in a piece of metal, but the lighting and composition are pretty nice, IMHO. It makes me happy to look at it. Please forgive my little self-indulgence. Anyway, it is something to look at.

I have the parts for the 1st brace/lever rack completed save for silver brazing the flange to the tab that goes on the bell end. I still have to file off roughly a half of a millimeter of material from the concave face of the tab to get it to fit where I need it to be. Right now it is too low for me to reach the levers comfortably. this is because with the flange in place it is too long and must be slid down where the bell is a tad narrower.

I will fix that tomorrow and braze the flange on.

Then I can soft solder this mess to the horn.

I have to drill and tap the holes for the two lever rack screws, too. Also, I discovered that I need my two finger rings on the backside moved over about a half-inch to make everything work together nicely. I will probably just keep them off the horn until the levers are finished.

I also have the Big Cuts to make on the base plate to allow the levers to have more than the needed clearance for their arc of travel.

I am happy with what I got done over this past week.

If there is anyone still reading my little saga: here are some nice pics for you…

I got the slide end wired down so I could work out the details of the bell end. The bit of shop towel taped to the slide tube is to cover the very sharp ends of the baling wire. Usually, I don't pay any mind to these, but I needed to get my fingers in and around that area over and over, and had already sliced the back of a finger, so I added the little "diaper" for safety. No one enjoys tetanus.


You can see the compound problem for me and my trusty Dremel tool. Finish fitting the flange to the bell. Then the tab must be curved and tapered to fit the shape of the flange, keeping the tab perfectly in line with the one on the other end. Time to whip out the old "eyecrometer"…


The Kurath is on its bell on my bench, so this is upside down. And… MISSION ACCOMPLISHED! The flange fits the bell. The tab fits the flange. After a little adjustment, I can braze this together.


I had to nibble off 2 mm from the end of the plate for it to fit. I eyeballed the length. I was wrong. BUT NOT BY MUCH! This looks really good to me. You can see how low it is compared to my target circle. Again, this is due to my having to sand the tab's cutout down a little more. I made it too big on purpose. (It is rather difficult to lengthen a metal part that is too short, you see…) And yes, the "diaper had fallen off an hour earlier. Whoopsie…


Again, you can see how well the flange and tab shaping went.


Here it is from the player's perspective…

I am looking for lever platens and have an ad posted in WTB. HMU if you have something like what I am looking for.

THANKS!

viewtopic.php?t=4779

You guys are great! I got what I needed, and had a number of offers for sales and trades within a few hours. I committed to one and no longer need any of these parts.

Thanks to all who emailed and PMed me about this!

Wade

I'm taking a little break and will start work up again soon.

Y'all take care!

Well, to prevent my having to remove the springs they are on the wrong side of the levers, and they will likely be oriented 180º to be seen from the spring end…

… but yeah, sort of like that…



The springs have such long tails because these SUPER STIFF (and very old) nickel silver wire springs were too difficult to easily move. I had to unwrap one loop to set the spring rate with the feel that I like. I have not trimmed the ends yet because I need to feel them with the weight of the linkages and valves acting against them. I might have to add that loop back to the wrap.

I am still considering using Mirahone platens on my lever arms, but now that these finally arrived (sent almost seven weeks ago!) I am again considering them.

Nervously awaiting the timer to go off so that I can take this out of the vinegar "pickle".

This is the bell-end tab for the bell-to-1st brace/lever bracket. This was a cast iron female pooch to get just so, and I am worried that I FUBARed it when I brazed the flange to the tab. I am completely out of materials now, so if this goes awry I am done working on this for a few months. As you can see, my flux has somehow become contaminated, cleaning very little, but creating a smokey mess.

NOICE!



Oh, and in the local elephantine news: During our epic downpour all day I discovered we have water coming inside in three new locations. Added to the previous six, we now have nine roof leaks. CRAP!

I know about "pickling solutions", but - when I stick just-now silver-soldered stuff into Allied "Slime Away" to quench (holding onto the part with some old funky who-cares-what-happens-to-them pliers), it seems to do a dandy (and sorta instantaneous) job.

Your part looks good !

It is pouring outside and my work table is in two inches of water, so I did a very limited amount of soldering, some of which was brazing, which really sucked to do in my laundry room, but I got it done. It was messy; brazing quarter-inch thick bar stock to a 0.5 mm thick disc SUCKS!

The flange ended up warping a bit because of how long it took my little 2 mm tip to heat that chunk of metal. I tapped it down to fit fairly well, without any embarrassing gaps around the circumference. The crucial angle came out pretty dang good, too.

I did zero buffing but had a boo-boo I had to scrape and sand a bit. I removed the vestigial 1st brace flange from the dogleg
and did a quickie polish to see how much cleanup I will be doing tomorrow.

Once all that is done I can look at how much of the big plate needs to be hogged out to make it into the big U-shape I have been working toward.

I will fit the lever rack to the plate and braze on the coins the first day after Noah's Ark sets sail. (We were trapped at home for hours due to the street and yard flooding. Our outdoor kitty wisely decided to come inside.)

Pics…

PROGRESS!

I will braze the coins to the levers after lunch.

I'm done for today. The coins are crooked. One day I'll take them off and correct that… but that will not be today. Nope. Today was "good 'nuff"…

PHOTO OF THE DAY


Horn be on the bell, levers be danglin'…


I thought about making 6th/2nd shorter like on four-paddle sets, but I said, "Naw, it'll be fine." I think I would dispute myself now. Luckily, the coins are more than big enough.


Good help is hard to find, but cute help is always at hand…

I'm NOT some amazing eye-baller who can spot exactly how something (ex: a round object) should be "clocked".

trick: (shown to me c. 40 years ago, by a guy who fixed horns, and - also - drank and smoked, so he never made it to the age I am, today)

When something is thought to be located properly, tack it with a TINY about of lead solder. Stare at it for a while, and - if it continues looks right - go ahead and silver braze it. (Otherwise, move it, and stare at it for another while.) That tiny amount of tin/lead isn't going to compromise the bond.

They *were* straight. I carefully measured and scribed alignment marks. But I bumped the unclamped work a little without knowing it, so they are both off by about the same amount. Not clamping the parts together seems like a stupid thing to do, but my silver soldering jig is just terrible about slipping when up to temp. If I clamp the work down so that it does not shift it dents the metal. I have become fairly adept at brazing without a clamp.

But not today, apparently…

I'll fit is later. I have to take all this apart and reinstall everything and clean it carefully. Right now I am trying to piece together a system of sorts, and once I have all the pieces I can go back and make corrections. I gave up on installing one bit, cleaning it up nicely, then creating the next bit and installing that and cleaning the snot out of it, too. I was getting beautiful parts that were not properly worked out, so all that effort was wasted.

So, for this part of the build, I am hacking, slapping together, bending, adjusting, and writing down everything. AFTER I have this mess "created" and everything works really well, *then* I will make it look pretty, I can also make new parts if I messed something up or decide it needs to be different.

I am assuming that eventually, I will have rebuilt this tuba from the ground up at least twice. It is frustrating, but I seem to be in fairly uncharted waters, here. I have not found a lot of 4+2 tubas with the rotor levers being behind the 1st slide with the valves after the pistons.

That means I am flying outside my normal comfort zone as far as making WAGs with an expensive tuba.

I'm a bit of a slow-witted dullard, but I'll eventually get it.

Oh, and thanks to @bloke for the suggestion of the 2 Franc coins; they were a great choice. The smaller 20 Rappen coins I had planned on using would have looked weird with the spacing of my levers.

I have a couple of old (1960's) clamp arrays that are deemed to be "good" (when I clean off all the rust)...but they can still slip (balancing act between "tight" and "marking something up").

I use them sometimes, and - other times - I do the "tiny amount of lead solder at one end, double check, a little bit of silver solder at the other end, go back to the lead-soldered end and poke in some silver solder, and then fill the rest of the braze joint.

Depending on the config, difference in mass, and other factors (awkwardness...??) I might choose one over the other.

Those coins look really good.

I wondered how they would look (with no nickel-brass teardrops underneath them).
They look great.

They are a little weird-looking, but I like them. I'm glad I decided to cut reliefs and set the coins flush with the levers rather than just plopping them on top of the arms.

the elephant wrote: ↑Thu Aug 25, 2022 10:56 am ...I'm glad I decided to cut reliefs and set the coins flush with the levers rather than just plopping them on top of the arms.

yes

Working out the puzzle that I have created for myself…

Of the two 6th linkages, the one I like less seems to work better. It looks like a small pillow block, two Minibal ends and two T hinges will have to be used for the 6th.

The upper 5th will need one Minibal and one T hinge. It will be a mostly straight rod, while the 6th will be a fancy-schmancy L with other little bends to make it fit in the space that exists.

6th…
A small pillow block will be needed on the bottom of the 1st casing to keep the rod from flopping all over Kingdon Come, making a racket when the 6th is pressed. I detest soldering stuff to piston casings.


Here is a long shot with the pillow block more or less where it would have to go. The red Sharpie on the rid is the travel area that has to pass inside the pillow block.


The pillow block kept falling off the rod when I tried to take this one, so the blue rectangle at the top is where it should be. The other blue end is where the T hinge (or another Minibal)would have to go on the lever.


Here is the end of this big "L" rod. It has a few small bends and tweaks to it to allow it to fit and run within that small space. I would put a half-T hinge (only one rotational axis) on the end of the L rod and a short arm with a Minibal to the stop arm on the valve.


5th…
The rod would need a T hinge at the lever and a Minibal screwed to a disc that has been brazed to a corner of the existing "Z" rod. Simple, but not, as there will have to be a straight bit at the "Z" rod end to go around that slide tube.


All this is just fooling around and scalp-scratching at this point. I have more or less eliminated the other "C" rod from consideration, which is a shame, as it is clever and was a PITA to make. Now it is just a bent-up brass rod in a scrap box. Oh, well, such is "progress"…

I made a thing!

Here is the pillow block for the 6th valve, which functions as a pillow block but is fashioned like the main bearing caps in an engine; it works pretty well, too.

I discovered that once things were aligned as well as I could eyeball them, the "L" rod won't work. So I am back to the "C" rod I worked so hard to make. So I made the needed pillow block and now I can fashion the connection from the rod to the short arm between it and the stop arm of the valve.

Once that has been done I can connect the other end to the lever.

Pics…

I have only ever owned L-shaped or T-handled hex keys. This hex driver is a great addition to my tool collection. The straight handle and ball end make this quite useful where T or L keys won't work. I may just have to buy a set of these guys.

Highly recommended!