3rd vale sticking with 3rd valve slide

Discussion in 'Trumpet Discussion' started by BobtheBigFoot, Apr 18, 2012.

  1. BobtheBigFoot

    BobtheBigFoot New Friend

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    May 15, 2011
    My 3rd valve sticks (it does come up but verrrrry slowly) whenever I use the 3rd valve slide. This especially happens when I slur up and down and have to press the 3rd valve and throw out the slide (such as a C#). Any one have this problem? I do keep my valves well oiled and i do keep my trumpet clean. Could my valve casing be slightly bent?
     
  2. bumblebee

    bumblebee Fortissimo User

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    Jan 21, 2010
    Great Southern Land
    I am sure somebody who really knows will respond shortly (and shoot me down too) but I think I have occasionaly observed this with a couple of my trumpets and have some incompletely thought through theories.
    One approach I've idly thought through without testing or talking through with anyone goes something like this:
    There is always some positive air pressure in the leadpipe because I'm blowing.
    When I kick out the 3rd valve slide the air pressure in the third slide drops below the ambient pressure.
    When I depress the 3rd valve the air pressure in the third valve slide rises above the ambient pressure.
    When I release the 3rd valve and pull in the 3rd valve slide the air pressure in the third valve slide increases a bit more above the ambient air pressure.
    This extra air pressure from the 3rd valve slide and from the leadpipe pushes the 3rd valve piston very slightly more firmly against the valve casing, slowing its travel. Finally it rises enough for the air under pressure from the leadpipe to vent through to the 2nd valve. Due to the proximity of the ports in the piston the "exhaust port" of the valve is probably never fully blocked, but the 3rd valve slide will be fully isolated before the valve returns to the upper position.

    If you keep the 3rd valve slide kicked out does your 3rd valve piston return slow down? If you pull the 3rd valve slide in before you release the valve does the piston slow down?

    --bumblebee
     
    Last edited: Apr 18, 2012
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  3. tobylou8

    tobylou8 Utimate User

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    Virginia
    To answer your question," Could my valve casing be slightly bent? ". I don't see how since it only happens when you use the slide. If it were bent, it would happen all the time. Are you flexing the casing while using the slide? Only if it's made of "Indian/Chinese/Eastern European" brass i.e. thin. What kind of horn is it? And as for as cleanliness goes, one mans clean is another man's filth. Ever change your felts? Could be worn enough to cause pieces to sneak into your casing.
     
  4. Ed Lee

    Ed Lee Utimate User

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    Aug 16, 2009
    Jackson NC
    It could be an over tight grip against the valve casing or that finger having depressed the third valve at an angle causing the valve to grab the valve casing. My advice is to learn to play with the tips of the fingers and not the pads ... and not use the pinky ring unless you are changing to a mute and must support your instrument with the right hand while doing so. Ain't sayin' this corrects the problem, but it eliminates such from consideration as cause.
     

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