TromboneChat

When you remove the cap (not the valve top) there is a set screw. What is the set screw for?

On my Mirafone tuba the set screw fits in a dimple on the rotor and "preloads" the valve stem to keep it centered. It should be adjusted by a tech and LEFT ALONE.

Not the same thing at all, Bruce. Hagmann valves are held in place by the spring. The valve cap is basically a dust cover. I assume he's referring to this. You see that little screw at the bottom. Good question.

Brad, if you don't know what it's for we need Mr. Hagmann himself to explain.

I'm guessing it helps in the manufacturing process but that is obviously pure speculation.

I kind of assumed it waa so you could move the valve around (checking rotation, pulling the core out of the casing, etc) safely.

Yeah I always wondered that too. It has no role in the valve actually functioning, I assumed it plays a role in manufacturing. Pure speculation but I'm thinking maybe it's used to attach the core to whatever tool they use for lapping?

Yep, that's it. I looked at my Hagmann lapping tool and it has a small notch that fits over the screw so that you can rotate the valve by hand.

brassmedic wrote: ↑Wed May 25, 2022 3:43 pm Yep, that's it. I looked at my Hagmann lapping tool and it has a small notch that fits over the screw so that you can rotate the valve by hand.

That’s interesting. Did you get that tool from Rene’ Hagmann?

I always just assumed the screw or pin served as a reference mark for the port, tubing and spindle alignment on the valve core. I imagined that the pin was installed and then the tooling used it as stop point for machining the ports.

Crazy4Tbone86 wrote: ↑Wed May 25, 2022 8:59 pm

brassmedic wrote: ↑Wed May 25, 2022 3:43 pm Yep, that's it. I looked at my Hagmann lapping tool and it has a small notch that fits over the screw so that you can rotate the valve by hand.

That’s interesting. Did you get that tool from Rene’ Hagmann?

Yes it was from Hagmann.

I always just assumed the screw or pin served as a reference mark for the port, tubing and spindle alignment on the valve core. I imagined that the pin was installed and then the tooling used it as stop point for machining the ports.

Don't know. The valves do have witness marks, so those are used for alignment. I don't know how they are made. Guess you'd have to go to the factory.

brassmedic wrote: ↑Thu May 26, 2022 2:26 am [quote=Crazy4Tbone86 post_id=179296 time=<a href="tel:1653533957">1653533957</a> user_id=8392]
[quote=brassmedic post_id=179273 time=<a href="tel:1653515037">1653515037</a> user_id=4102]
Yep, that's it. I looked at my Hagmann lapping tool and it has a small notch that fits over the screw so that you can rotate the valve by hand.

That’s interesting. Did you get that tool from Rene’ Hagmann?
[/quote]
Yes it was from Hagmann.

I always just assumed the screw or pin served as a reference mark for the port, tubing and spindle alignment on the valve core. I imagined that the pin was installed and then the tooling used it as stop point for machining the ports.

Don't know. The valves do have witness marks, so those are used for alignment. I don't know how they are made. Guess you'd have to go to the factory.
[/quote]
I would LOVE to go Switzerland on a “research” trip. Maybe I can ask TromboneChat to sponsor me….LOL!

The last time I was in Switzerland was in 1999 on our honeymoon. Made some side trips to the Willson and Hirsbrunner factories. The jewel location of that trip was a small shop in Thun that sold old instruments bought from town bands across Europe. I was able to buy a Besson Euphonium and a Glassel trombone for a combined $120. Had I known about Hagmann’s store and company in Geneva, we certainly would have stopped there!

My wife (not a musician) was a real trooper when we made those side trips to music places……very tolerant. She even carried some of the instruments as we trekked through train stations and airports. To this day, she is still very tolerant of my instrument collecting and experiments. We both agree that there are thousands of vices that could be worse!

Don’t really know how I ended up talking about our honeymoon. I guess that would be considered a rather random tangent!

I haven’t been in Lausanne, Switzerland since we looked over the boarding school that would attend called Chateau Brillamont about 1969. That is where her cigarette smoking career started and ended.

I spent Desert Storm at Rhein Main AFB. The gate we used was closer to Mainz than Frankfort. We did go see a Zeppelin museum that was probably very close to his shop. I did not know that he was there. And I really could have used a trombone at that point. Years later Mr. Alexander discouraged me from purchasing a rotary valve bass trumpet and he was right.

I now own an LT42AG Bach large bore with gold brass bell, lightweight nickel slide, and a Hagmann valve. I followed this thread with interest.