TromboneChat

The valve on my shires is noisy. Mostly it “thunks” on engaging and disengaging. The horn is less than a year old. What should I do? I’ve oiled it with hetman light rotor oil, and bearing and linkage oil on the linkage and bearings. Doesn’t seem to be mechanical, it’s almost like the bumpers are too hard?

Yup, sounds like you diagnosed that correctly

I took the whole thing apart. Found one slightly loose screw. Oiled and cleaned everything, double checked rotor alignment, reassembled, and it’s a bit better but still loud. Interestingly, it’s quite a bit quieter when the valve section is off the horn. The bell makes the thunking resonate.

How do the bumpers feel to your fingernails? If they feel like tapping a pen instead of taking a bit of your fingernail-print, they're probably the culprit.

Feels pretty hard. Seems odd for a new horn. Oh well. What do you folks recommend for a softer bumper material?

Before you do that, make sure that the ball joints are oiled with heavy ball joint oil and that the linkages are tight.

Amconk wrote: ↑Wed Dec 25, 2019 9:31 pm Feels pretty hard. Seems odd for a new horn. Oh well. What do you folks recommend for a softer bumper material?

I usually use the cheap clear and soft plastic sticks used as fuel in glue guns, they come in different diameters, are neither to soft or to hard, are easily shaped with an scalpel, and tada, for stubborn horseshoes which throw them off, can be glued in place. Easy to find and cheap.

All better! I went down to my local Ace Hardware and bought a 3/16 width o-ring for $0.99, and a pack of razor blades. Popped out the old ones (which felt like hard plastic) and cut to fit two new bumpers. Shaved them down until the guide lines under the cap lined up perfectly and voila! Nice quiet rotor, no bounce, and lines up better than before. Plus I got enough rubber in that one o-ring to make about 50 more, so I’m set for years.

Concerning "hardened" rubber bumpers.....think about where you store your instrument. For years, my horn was constantly stored in my car. I did most of my practicing at my college teaching studio and I would travel to gigs and such. I would take it in my house to do the occasional cleaning and maintenance, but essentially the trombone lived in the car for many hours each day. During its car habitation, the poor trombone was exposed to extreme cold in the winter and extreme hot in the summer. Thus, the rubber bumpers aged and dried out very quickly. I was changing the rubber bumpers about twice a year, probably more, because they would harden and get very noisy.

When I thought about the abuse my horn was taking with weather extremes, I started taking my horn inside whenever possible. Now my rubber bumpers last for many years!