Reversing a tuning slide?

[ithinknot]

Perhaps I'm missing some important point.

Yes. What you say is true for valve wrap tubing but not the open horn, as Doug has just pointed out and various posts above set out further.

Bell stem ID invariably more-or-less matches TS upper outer leg ID, not inner leg ID, so there's no bore gap whether pulled or unpulled; just a step up either from inner to bell stem, or inner to outer. In that case, the "no gaps when closed" situation to which you refer does not apply. Obviously, "no gap becomes a gap" is one possible option on the lower side but, again as discussed above, the "reversed" configuration can be applied to a variety of taper/ID choices, some of which exclusively give stepped bore increases whether closed or open.

[Burgerbob]

Again, this is about main tuning slides- if you have a reversed tuning slide, you get a much longer uninterrupted tapered gooseneck before it goes into the tuning slide (and therefore a gap).

[tbonesullivan]

Perhaps I'm missing some important point. If there are no gaps when the bell bow is pushed all the way in (male/male, female/female, or hermaphrodite), so that the two arms (of different bore size) are flush up against the corresponding tubing of the gooseneck and bell—and if there are no discontinuities in the sound-path in that configuration—when you pull out by any amount, there must be two gaps created, no matter which combination of male/female, &c., is being used.

There was discussion before in the thread of a hermaphroditic (reversed) style where the inner diameter of the crook would be equal to the inner diameter of the outer tuning slide. This would involve and outer slide that had a larger outer on an area at the end, where the crook / bow would go. This would also most likely require increasing the wall thickness of the outer slide, so that it had room to accommodate this "shelf" where the tuning slide crook would rest. There would then be something similar on the outer slide of the bell side as well.

This would eliminate the annular "gap" though of course there will still be a step increase in bore size at the end of the inner tuning slides. Basically it would be accomplishing what the Romeo Adaci tuning slide, but with more pieces.

[tbonesullivan]

Again, this is about main tuning slides- if you have a reversed tuning slide, you get a much longer uninterrupted tapered gooseneck before it goes into the tuning slide (and therefore a gap).

Well, "possible" longer tapered goose neck, if the goose neck is continuous with the inner tuning slide, which usually it would not be. Most I see have the inner tuning slide as an additional piece, which is cylindrical.

I do remember hearing that the reversed tuning slide on Bach 37 trumpets results in a longer leadpipe, but is that taper continuous into the inner tuning slide of the trumpet?

[Doug Elliott]

No gaps. The female side is the same ID as the next tube in sequence - same as the Romeo Adaci example, but assembled instead of being a single tube.

[elmsandr]

But we're not talking about valve slides here... we're talking about a significantly tapered crook with the possibility of no gaps if you make use of the straight tubing as part of the overall expansion.

Yes, I'm aware of that. I'm just using valve slides as examples of male and female coupling.

Perhaps I'm missing some important point. If there are no gaps when the bell bow is pushed all the way in (male/male, female/female, or hermaphrodite), so that the two arms (of different bore size) are flush up against the corresponding tubing of the gooseneck and bell—and if there are no discontinuities in the sound-path in that configuration—when you pull out by any amount, there must be two gaps created, no matter which combination of male/female, &c., is being used.

There will be a discontinuity any time the slide is in use, so don’t optimize for that. Optimize for eliminating the second gap.

Does that make sense?
Andy

[bigbandbone]

I reversed the tuning slide on my 20H. Along with some other mods I turned it into a 4H on steroids!
The tuning slide conversion was pretty easy, but I did need to turn one piece on my lathe.