a strategy for permanently installing a 5th rotor (whereby the rotor is easily removable for servicing)

[bloke]

These are the requirements (in my view)

- The rotor body should be easily removable for cleaning or repair.
- The center screw should be approachable and easily reachable - with a screwdriver being able to be absolutely vertically aligned - in relation to the rotor center screw.

I offer no criticism of detachable rotors, mouthpipes, and braces, but (mostly) they're not what I choose for my builds.
It's nice to be able to completely remove a valveset (or a rotor casing - allowing a builder/user to be more carefree via positioning a rotor in just about any position).
OTOH, detachable brace screws can work loose and pressure coupler-style tubing joints' knurled nuts can loosen as well, and such builds take more time than the (already epic) time it takes to remove all the body/slide dents even BEFORE proceeding with a XXX-hours build.

It can easily be argued that - puzzle solving ("how can I mount this rotor body permanently, whereby it's serviceable?") also takes time, but (it just seems to me) way less time (and money) than buying or fabricating detachable brace assemblies.

With my compact Holton BB-flat (suspiciously all absolutely interchangeable bows and bell with York 33, whereby there is controversial discussion as to who actually built these Holton bugles) this is how I managed this:






and whereby the knuckles from the rotor casing point off in a usable direction





The mouthpipe is very messy...A few days ago, I slightly repositioned it.
Of course, the entire tuba is messy.
I'm not cleaning up any solder joints (even though I've been playing this instrument for several years) until I take care of a few final issues (with which I'm slightly dissatisfied).

(DIFFERENT BUILDS ARE GOING TO REQUIRE DIFFERENT CREATIVE SOLUTIONS AND WORK-AROUNDS, OBVIOUSLY.)

If I can design a tuba whereby nothing more than SLIDES (vs. normally non-removeable parts) can be removed in order to service a rotor, (at least, to me) that seems to be a much simpler way to deal with this issue.

[the elephant]

Do you mean the rotor and back bearing plate are accessible for removal from the casing, or that the entire valve and slide assembly is removable as a unit? I usually do the latter. This gives me a lot more flexibility as to location and clocking, as well as slide wrap. I just remove the whole banana and service it on my bench away from the tuba, then reinstall it. When you cannot do this, the location and clocking of the rotor case can be really tricky. Some instruments just don't want a 5th valve where it needs to be. Some are very easy. I will come back tonight to see what you have shared.

[bloke]

The rotor and bearing plate (only) are removable from the instrument (and easily), just as with most any factory tuba (other than those Conn 5XJ C tubas).

Everything is soldered up "solid".

Yes, every instrument has its own particular issues due to the fact that no two tubas are routed the same, but this is an example of one instrument that could have had its issues addressed via detachable braces and detachable compression fitted tubing, but - instead - I addressed the two requirements:

- rotor and bearing need to be removable
- center screw needs to be accessible

via removable slides (which are removable without tools, because - well - they are slides).

Here's a view of the clear shot (for a screwdriver) of the center screw with the third lower slide and the short little fourth valve circuit slide both removed: