Upper leg wobbliness on dual bore slide

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bassboneman69
Posts: 59
Joined: Wed Aug 15, 2018 7:44 pm

Upper leg wobbliness on dual bore slide

Post by bassboneman69 » Mon Feb 22, 2021 11:21 am

I have an older Edwards Bass dual bore slide.
I am not sure if this is a recent issue OR has been there and never noticed before...
In playing position the upper leg has a slight wobble from side to side (left/right).
Obviously, it is more noticeable in 4th to 7th.
Is this a normal issue?
I love this side and hope to keep it that way!!
Crazy4Tbone86
Posts: 419
Joined: Tue Jan 14, 2020 10:52 am

Re: Upper leg wobbliness on dual bore slide

Post by Crazy4Tbone86 » Mon Feb 22, 2021 11:42 am

I am, probably like some others, wondering if you have the wrong outer tube on the top slide. It is very easy to tell with that model. Does the top outer slide fit on the lower inner slide? If yes, you have the wrong tube on the top.

If the top outer does not fit on the lower inner, then you should check the tolerances. You (or your tech) can measure the widest spot on the inner stockings and the inside of the outer tubes. The difference should be in the .011 to .014 inch. That is considered the normal tolerance range for a trombone slide. If the difference is more than .014, the slide could leak air and lack compression. If the slide is .010 or less, it will need to be super straight and parallel to have free movement. When the tolerances get down to about .007, it is nearly impossible to have great slide action (I have seen that on a few Chinese stencil trombones).
Brian D. Hinkley - Player, Teacher, Technician and Trombone Enthusiast
Crazy4Tbone86
Posts: 419
Joined: Tue Jan 14, 2020 10:52 am

Re: Upper leg wobbliness on dual bore slide

Post by Crazy4Tbone86 » Mon Feb 22, 2021 11:55 am

Just for clarification....

When I say "wrong tube on top," I am not saying that you accidentally have your slide upside down. I am saying that your trombone was assembled with the wrong tube installed on the top half. I have seen wrong parts installed on instruments before......it definitely happens!
Brian D. Hinkley - Player, Teacher, Technician and Trombone Enthusiast
brassmedic
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Re: Upper leg wobbliness on dual bore slide

Post by brassmedic » Mon Feb 22, 2021 11:42 pm

The outer tubes ride on the stockings. The rest of the inner tube is a smaller outer diameter, so there is going to be a lot more play at the top of the slide where it isn't touching the stockings and there is room for the outer tube to move back and forth in relation to the inner slide. That is by design. If the whole inner slide were the larger diameter of the stockings, the slide wouldn't move easily. I wouldn't worry about it. If you are concerned that the slide compression isn't good, there's a "poor man's" compression test that's easy to do. Take the slide off the bell, plug both inner tubes with your fingers, hold the slide vertically a foot or two off the floor, and let the outer slide fall under its own weight. It should fall fairly slowly, taking a few seconds to hit the floor. If it falls quickly like it's freefalling, then your compression isn't very good. Make sure you have your foot underneath or some way to catch the slide so it doesn't slam onto the floor and get damaged.
Brad Close Brass Instruments - brassmedic.com
bassboneman69
Posts: 59
Joined: Wed Aug 15, 2018 7:44 pm

Re: Upper leg wobbliness on dual bore slide

Post by bassboneman69 » Tue Feb 23, 2021 3:36 am

Thank you Crazy and Brad.
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