conversion tactic: Miraphone LH long length 5th to RH 5th short length 5th

[bloke]

yeah...
This is the blingy (1960's factory 5-rotor model 186 C) tuba that I decided to sell to Bill.
I dunno who took the picture, but - due to the unusual finish - it actually shows (more clearly than might a picture of lacquered brass) the ALTERED routing required for (WITHOUT changing out the #5 STEM-DOWN rotor body) converting a VERY OLD 186 5-valve C (long-length, LEFT HAND) to a RIGHT HAND/short-length 5th valve.

The dogleg (supplied by Miraphone as part of the conversion parts) must be moved AWAY FROM the #5 casing (to allow for the mechanism), and - with the necessarily wider spacing - (rather than the Miraphone-supplied hidden LOWER slide bow) the W-I-D-E bow - (which can be harvested (or bought from Miraphone) from an oem 186 B-flat 4th circuit - should be used. Due to the extra-wide hidden slide bow, though, the lower (hidden) slide tubes must be shortened. (With this particular instrument, I shortened those two slide tubes BARELY enough so that "low F" would be "just" in tune (with the upper 5th slide all the way in) IN ORDER THAT there is ENOUGH PULL available for the (5-2-3-4) "low D", which (with no pull whatsoever) is VERY sharp, with this 5th circuit system (as 5-2-3-4 is the only viable choice for "low D").

Also (see picture) this also requires that the brace (supporting the #5 UPPER outside slide tube (towards the outside edge of the instrument) be braced with a much taller brace. (I managed to find a sturdy Miraphone brace that was just the right height.)

Whether this adulterated version or the Miraphone (stem-up) version, the LOWER/hidden slide is quite awkward to pull and empty water. thus: the waterkey which I chose to add.

[bort2.0]

The work looks great! And I fully appreciate the water key at the bottom of that 5th valve tubing. A necessity on many tubas, IMO.

[bloke]

The work looks great! And I fully appreciate the water key at the bottom of that 5th valve tubing. A necessity on many tubas, IMO.

I know that you understand that it's a slide, but (just to clarify) it's not fixed tubing, but (again) an (albeit very WIDE) slide.

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I typically add SEVERAL water keys to my personal tubas, and - when building "project" tubas for myself - always load them up with SEVERAL water keys. I am NOT a during-an-oboe-solo slide-clanker/visual-distraction-creator, and I do NOT buy into waterkey-nipple/nodal-disturbance voodoo.
(My project Holton currently features seven water keys - including one on the UPPER #1 slide, and I'm considering adding more.)

[bort2.0]

Point is, I like a water key there :)

I agree about adding them in strategic places, too. The back tuning of the MTS pretzel is a good place too. My Rudy seems like it would benefit from one, much like my old MW-30 did.

[the elephant]

Not to hijack, but to add to the boiling cauldron of creativity shown here, I did not think this topic needed its own thread, but fit in nicely with Joe's topic. Sort of a "two-fer"…

If you are ADDING a 5th to a CC 186 and do not have one of the very nice 5th-specific rotors, a regular one can be swapped in. Solving the rotation direction issue is something each person has to decide on. I opted to use a 3rd casing with a 1st rotor in it because that required the least futzing around to make it work. (That is essentially a 5th rotor unit without the funny, turned knuckle.)

So Joe's way is a top-notch way to fix that specific issue, and mine will allow you to retrofit a 5th if you already have a pair of old valves in a box somewhere. You could do it with one, but you have to sort out where the connecting linkage will hook up and that it rotates toward the hand rather than away like the other four valves.

My method uses two of the lower 5th crooks, a stock dogleg, and I made the "double knee" from an old 1st crook and a ferrule. Yes, I could have bought all new stuff, correct stuff, and I did that for my "nice" 186. This one was an unknown player and I wanted to limit my budget as much as possible. So budget-minded shortcuts were used.

Joe's solution and mine look similar since they both use the same lower crook up top. Mine is just shoved over toward the 1st slide, and his slide is shoved in the other direction. Both work very well, both cost a lot less than buying all new stuff.
Aesthetically speaking, I like Joe's better as that crook is very similar to the old-style 5th crook (if it is not the very same) and his offset to the outside looks a lot more like the classic 186-5U CCs of the old days, except that the outer run ducks back behind the valves much faster than the old flat M3 setup. I still like that length of the 5th slide the best but would never confuse myself with it unless I converted all my 5th slides to match.

[bloke]

That’s clever, and only slightly more expensive.
… though some of us (via age and past opportunities) have two or three globs of old 186 rotor clusters laying around (likely, from which at least one good rotor casing and bearing can be harvested) which are always handy.

Old Miraphone rotors – even if damaged (as long as they’ve never been “repaired” by a “tech”) - are often not much worse than new.

[the elephant]

Yes, I have a box of the beasties, too. Very handy.