Not fully screwed in valve bracing

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BassBoneWaluigi
Posts: 52
Joined: Nov 24, 2022

by BassBoneWaluigi »

On my Getzen 3062, the screws on the bracing do not look fully screwed in, yet I can not get them to keep turning. Is this an issue with the horn, or just how it is supposed to be?

Thanks in advance
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Burgerbob
Posts: 6327
Joined: Apr 23, 2018

by Burgerbob »

If the braces meet, then it's no big deal
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Matt_K
Posts: 4809
Joined: Mar 21, 2018

by Matt_K »

Personally, I’d take it to a tech to ensure it was all properly aligned. It’s probably fine but getting everything lined Sp well typically makes an instrument play better
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Burgerbob
Posts: 6327
Joined: Apr 23, 2018

by Burgerbob »

[quote="Matt K"]Personally, I’d take it to a tech to ensure it was all properly aligned. It’s probably fine but getting everything lined Sp well typically makes an instrument play better[/quote]

No need for a tech to check. Just unscrew the nut and see if the braces meet up correctly.
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BigBadandBass
Posts: 270
Joined: Feb 13, 2020

by BigBadandBass »

My shires also has this, you can always have a tech see if they’re out of alignment or not matching
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Matt_K
Posts: 4809
Joined: Mar 21, 2018

by Matt_K »

[quote="Burgerbob"]<QUOTE author="Matt K" post_id="207151" time="1681082323" user_id="48">
Personally, I’d take it to a tech to ensure it was all properly aligned. It’s probably fine but getting everything lined Sp well typically makes an instrument play better[/quote]

No need for a tech to check. Just unscrew the nut and see if the braces meet up correctly.
</QUOTE>

Perhaps, but I've had several parts that fit as described way and a couple seconds of torch time got it that last 1% in alignment before and it felt like the heavens opening up. Could just be placebo.
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Crazy4Tbone86
Posts: 1654
Joined: Jan 14, 2020

by Crazy4Tbone86 »

Not just a placebo! Most people assume that the high-end modular horns (Shires and Edwards in particular) are completely stress-free in their construction. I have seen many with braces that were not lining up properly. Making those braces line up perfectly and allowing those threaded connectors to hold things together with zero stress makes a huge difference. It can turn a lemon into a top-notch instrument.
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elmsandr
Posts: 1373
Joined: Mar 23, 2018

by elmsandr »

So… the threads there are not the functional part. Ask yourself “how does this work”? The inside bottom of the nut pulls the brace against the socket. You want the threads you can see there to be extra so that you NEVER bottom out on the threads and the nut can do its’ job.

Cheers,

Andy
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Crazy4Tbone86
Posts: 1654
Joined: Jan 14, 2020

by Crazy4Tbone86 »

The nut really should not “pull” the two parts of the brace together. If it does, that will create tension and stress. The two parts of each brace (if perfectly aligned) should touch each other gently and be perfectly centered without the nut. The nut simply prevents any lateral movement or rattle sounds of the connecting parts.
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hornbuilder
Posts: 1384
Joined: May 02, 2018

by hornbuilder »

<EMOJI seq="261d" tseq="261d">☝️</EMOJI>
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elmsandr
Posts: 1373
Joined: Mar 23, 2018

by elmsandr »

[quote="Crazy4Tbone86"]The nut really should not “pull” the two parts of the brace together. If it does, that will create tension and stress. The two parts of each brace (if perfectly aligned) should touch each other gently and be perfectly centered without the nut. The nut simply prevents any lateral movement or rattle sounds of the connecting parts.[/quote]

Yes, in engineering terms, there will be tension and stress. That’s how threaded fasteners, or any rotationally secured fastener works. Proper alignment prevents excessive tension and stress, but screws/nuts/bolts do not work without some level of stress. It creates a ‘spring’ where you are generally stretching the bolt (usually elastically).

But I agree they should line up nicely before tightening so that you aren’t trying to close a large gap with the nut. In addition to putting more stress on the structure, that will also rob the joint of clamp load and it will come apart a lot easier for the same given level of torque.

Cheers,

Andy
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Crazy4Tbone86
Posts: 1654
Joined: Jan 14, 2020

by Crazy4Tbone86 »

Andy….you are exactly correct. Your point is the reason why some techs and players prefer the non-modular construction of a trombone.
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BassBoneWaluigi
Posts: 52
Joined: Nov 24, 2022

by BassBoneWaluigi »

K so nothing to worry about, thanks so much
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hornbuilder
Posts: 1384
Joined: May 02, 2018

by hornbuilder »

Maybe. Maybe not.

If you undo the nut, is there a gap between the threaded stud and the brace rod? Do they align correctly?
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Blabberbucket
Posts: 305
Joined: Oct 09, 2022

by Blabberbucket »

If there are no odd vibrations or buzzing when playing the horn, I wouldn't be concerned about this. It's the nature of modular horns, and I don't see anything unusual about the way the threaded braces fit together in your photos.

If you want to go down a rabbit hole of precision fit on modular horns, take it to a tech that is very comfortable with these types of instruments and expect to pay a bit to remedy assembly-line fit issues. If you're happy with how the horn plays and there are no odd vibrations or issues, leave it alone and get back to practicing.