King 6b vs 7b Wrap

[Fireinthebones]

The King 6b wrap has a sort of bend on the F attarchment that sort of resembles a French horn tuning slide while the 7b has a straight tuning slide on the f slide. Does anyone know why king didn’t use the same tuning slide design on both the 6b and the 7b.

[Matt K]

I don’t know the answer to the question, but I can tell you that the bend you’re referring to is called a shepherds crook.

[chromebone]

The earlier 7B’s had something like that type of wrap, but they were changed to the more squared off design when they moved the cross brace back. The 4B and 5B also had a similar design which was changed to the squared off design for the same reason.
When the 6B was originally designed, the idea of the wrap extending beyond the main body of the horn was kind of strange; in addition, the 6B was designed in collaboration with Alan Ralph, who was a first call studio and Broadway player at the time, and he probably wanted a compact horn to take into a theater pit. by the time the 7B came out, the idea of the attachment slides extending beyond the back of the horn didn’t seem like a weird idea.

[Kingfan]

The earlier 7B’s had that type of wrap, but they were changed to the more squared off design when they moved the cross brace back.

What he said.

[hyperbolica]

6B was dependent and the 7B was independent. That in itself isn't a reason to make a change, but it's a reason for them to be different. Plus, the shepherd's crook is unconventional in trombone design, french horns and cornets were the main instruments to use it. I would think that a more conventional U shape requires simpler tooling to bend. For mass produced horns, it often comes down to that.

[JohnL]

I think we're talking about two different things here...

What the OP, Matt, and hyperbolica are talking about is the crook on Duo Gravis' f-attachment, as shown here:

crook.jpeg

while Chromebone and Kingfan are talking about the characteristic King "swoop" that you see in many King f-attachments (along with a slightly smaller version that appears in the Duo Gravis' second valve), as shown here:

swoop.jpeg

AFAIK, the "swoop" originated with the 4BF; earlier King designs (Symphony models and early 3BF's) don't have it. It was eventually incorporated into all King f-attachments, but was lost when King moved the brace back to allow for a "thumb under" valve lever.

The shepherd's crook is unique to the Duo Gravis (at least as far as King trombones).

The "swoop" and the shepherd's crook make sense when you know that the DG and the 4BF were both designed by George McCracken, who is best known for his work designing and building French horns.

[BGuttman]

I think the Shepherd's Crook was intended to keep the Duo Gravis F tuning slide from sticking too far back. On my 7B the F and Gb attachments stick out some 5 inches or so beyond the tuning slide.

[ithinknot]

I think the Shepherd's Crook was intended to keep the Duo Gravis F tuning slide from sticking too far back.

Yup, plus the DG must be one of the first wrap designs that (in the normal course of playing position and vertical) doesn't hold water, while still being 'closed wrap short'.