TromboneChat

Thought others might find this interesting - from https://www.jlandressbrass.com/shop/Tro ... 379320.htm

.525" slide
.575" rotor with spring linkage
8 1/4" yellow brass bell

It's fun to discover that the distinctive post-valve offset on the TR181 was part of the Holton design vocabulary at least 40 years earlier.

And that bell taper!

That trigger mechanism is a head scratcher

harrisonreed wrote: ↑Tue Mar 29, 2022 5:03 pm That trigger mechanism is a head scratcher

It looks like there's some sort of gear linkage in there.

It would probably have a feel similar to a yo-yo style valve - which is probably what the original owner was playing before buying this horn.

JohnL wrote: ↑Tue Mar 29, 2022 11:58 pm It would probably have a feel similar to a yo-yo style valve - which is probably what the original owner was playing before buying this horn.

That's what I figured - an (over-)engineered version of the old German system

Does the offset have any meaning or intention?

robcat2075 wrote: ↑Wed Mar 30, 2022 11:15 pm Does the offset have any meaning or intention?

I mean, obviously it allows a wider attachment wrap than the span of a (presumably preexisting) main tuning slide bow would otherwise accommodate.

From a manufacturing perspective, it's complicated. Making a wider TS bow seems like it would be easy... just hand bend around a wider form... except the bow length would also increase, so you'd need to design a new taper, and that is trickier, because it will affect intonation and, well, everything.

My guess is that the extra manufacturing effort of the offset was considered less risky than interfering with a TS/bell taper pairing that was already known to work. It's a funny part; if it's tapered in the way of a normal neckpipe, then either it needs to be hydroformed, which isn't cheap, or it was hand bent and might not be particularly round or consistent. If it's not tapered, however, it can be balled-out like any other cylindrical part, and it might have been borrowed from a baritone or something else Holton was already making.

Just a guess.

If the tuning slide bow was pre-existing.... does that mean they had a trombone without the offset, placing the slide that much closer to the bell?

Is the offset something that happened when bells got larger?

JohnL wrote: ↑Tue Mar 29, 2022 11:58 pm

harrisonreed wrote: ↑Tue Mar 29, 2022 5:03 pm That trigger mechanism is a head scratcher

It looks like there's some sort of gear linkage in there.

It would probably have a feel similar to a yo-yo style valve - which is probably what the original owner was playing before buying this horn.

Yo-yo style valve? Not familiar with those. Many older German brass instruments had clockwork springs (or flat springs wound in a spiral) attached to the rotor spindle with a string linkage attached to a leather thong for the thumb.

It looks like a spring-activated system with a spring similar to a trumpet valve spring. The tube covers the spring and linkage, and a rod with a ring actuates the valve. I’m not saying I’m right, just what it looks like…

Kbiggs wrote: ↑Thu Mar 31, 2022 10:26 am...string linkage attached to a leather thong for the thumb.

That'd be a yo-yo.

robcat2075 wrote: ↑Thu Mar 31, 2022 10:21 am If the tuning slide bow was pre-existing.... does that mean they had a trombone without the offset, placing the slide that much closer to the bell?

Is the offset something that happened when bells got larger?

All possible, though the distance would also be tweakable with the angling of the slide receiver, even with a straight-ish neckpipe. Certainly they ended up with plenty of finger room in this case. This bell flare doesn't seem especially pronounced relative to the (seemingly very large) throat, so it's hard to know how much smaller any earlier relatives might have been if they were based on the same taper.