3rd valve slides on "professional" trumpets can be frustrating, due to casual oem tolerances

[bloke]

A university student brought a "professional" name-brand trumpet down from Kentucky for a student (a high school student who is attending an "improve your playing" summer music camp at a university).

The main slide was seized (lime, but - sure - was knocked out of alignment) and the 3rd slide alignment was crappy.

After straightening the bell (dipped down), freeing the main slide, and aggressively cleaning the mouthpipe to tube to a smooth brass interior (rather than a lumpy lime tunnel), I messed around with the main slide until it was aligned (one of those "reverse" mouthpipes with no vertical braces - and owned by a h.s. kid who marches with it (very bad combination), knocking out all the bell stem dinks, etc...

...I set out to align the #3 slide.

PER TYPICAL...The geometry coming out of the #3 casing (the two straight tubing knuckles) did not match the geometry of the #3 slide assembly braces...so - with the geometry of the movable slide braces defining a c. .0035" wider parallel than the geometry of the knuckles coming out of the valve casing (plus the factor of "you can wait on this, so you can head back to Kentucky with it", PLUS the "let's not f up the silver plating", PLUS "let's not run up a huge bill") I was only able to get that #3 slide working "pretty well" rather than perfectly. I remember back when this (Asian) maker's slides' geometry was always within .001" - .0015", but (as with so many other manufacturers and brands) it sorta looks like they're riding on their reputation...

...oh, and don't get me started about $15K - $20K European tubas' factory slide alignment (more like: "really lucky if one end is only c. .012" wider than the other end, much less coplanar", you can forget USA, and - as far as the super-economy China production - economy "production", which has nothing to do with how much retail mark-up has been added - is concerned: no comment)

This is another reason why - in the "lacquer vs. silver" debate, I tend to make a little face (which obviously cannot be seen in my posts)...I'm thinking...OK, with LACQUER, someone could take stuff apart, put it back together right, and ONLY have isolated messed-up areas in the finish that needs to be polished and hit with new lacquer...yet - with silver - ...

bloke "and - as far as the 'standards' debate is concerned, with this $3000 (yes: privately-owned) trumpet having been dropped numerous times, never cleaned, and rarely lubricated...EVEN IF the child is 'very talented' and 'works hard'...this supports the argument that when TAXPAYERS buy stuff for children to use at no charge to their parents, it NEVER needs to be 'professional quality', it just needs to 'work' - and (probably, if brass) with not particularly tight tolerances, so that - when these instruments are inevitably dropped on the floor, and never cleaned - they might (??) still continue to function."