TubaForum.net

I never looked at the alignment of the new-from-the-factory rotary valves I bought from Miraphone. They came with nicely fit and trimmed cork on the upstroke (rest) and neoprene (or maybe buna N?) on the downstroke.

And dipstick here never looked at the alignment markers because they have *always* come nicely aligned.

Well, the two I used on my Kurath were not. I just found this out about two months ago, but I have not had to use the F over the summer. So I only got to this today. It turns out that both the cork and neoprene bumpers were off. The cork had collapsed, and the neoprene was never trimmed, so it was too thick.

Further, once I took the valve section off the Kurath (with the leadpipe off of the 1st piston case), I could *easily* see the alignment, and it was off, too! Both upstroke and downstroke.

You read that correctly, lades and gentlemen: I had to re-level all 12 valve positions.

And I must say, the horn really plays well now. I was thinking my ear was going out due to my age. Nope. I'm fine. It was the tuba.

Service your horns, people. HAHAHA!!!

No one pays me to replace my bumper corks.
For a LONG time, I had little 1/4-inch-long pieces of paperclips (installed at gigs) jammed behind worn bumpers on my F tuba.

"cobbler's own shoes with cardboard in the bottoms"

… and professional mechanics have the worst cars…

I have been hearing a small leak for some time. I have chased it forever. That was the out-of-alignment 6th valve. Everything else I did today was just gravy.

I was starting to doubt my own workmanship. "Did I somehow screw this tuba up when I did all of this heavy modding?" Talk about being relieved when I discovered the misaligned valve last month. I just wish I had taken the time to clean up the thing weeks ago. But I have been busy playing a lot of CC, and the F has been collecting dust. I have an F gig tomorrow morning, so I pulled it out, and the sound of a tiny leak annoyed me enough that I stopped practicing and put it on the workbench. If I pressed 6th about three or four milimeters it would open up, and the pitch would sort itself out a bit. Once everything had been done, the scale was so much easier, especially in the "trouble range" of this horn, which is the bottom space Ab up to the middle line D. The only weird F tuba note on this horn is the low Bb, and it cleared up really nicely.

Time to get my stuff together for tomorrow.

A few years ago, one of the valves on my 5450 tuba (back before I sold it and started doing the B-flat thing) had one piston that kept intermittently dragging or sticking. There was a hair between the piston and the casing.

At least I was experienced enough to not start jacking with the piston or the casing, and simply waited out being able to figure out what was going on.

talking to myself:

hey bloke,
You didn't bump this thing and you didn't drop this thing. It's not broken. Just chill. You'll figure it out.

Emergency 186 cork bumper replacement: pencil eraser.

Sometimes with a little pocketknife whittling

Those Staedler long eraser pen-thingies I stole from my Dad held enough for 5 valves in a pinch!

When I caught myself completely out of rubber tuba rotor bumper material and needed to replace all of them for a school, I've run around the corner to the dollar store and bought pencils.

I have plenty of the stuff here. The issue with Miraphone's chosen neoprene is that it is very hard, so difficult to compress into the cork plates. Then you *still* have to trim them. You know, after all these years, you would think they would know the compression/"bulge" factor and use material that did not need any adjustment at all once installed. I mean, come on, guys…

Being German... I am surprised they don't have a micrometer adjustment screws on the stop plate for precision alignment and compression of the various stopper materials.

Somewhere, back in the last century, I had a piece of vacuum cleaner belt that sized up pretty well for the Miraphone bumpers. I think it might be with my reloading equipment....

We seem to be talking a lot about the bumper material here. Like, most of the replies have been about what you can use.

This is supposed to be about how I overlooked the valve alignment on my own instrument, thinking that it was a small leak.

Like for a long time.

I guess I did not make that clear. I will try harder next time.

Maybe we can combine bumper material and "two-wheeler dollies made from junk around the house" into one thread.

bloke wrote: Wed Oct 14, 2026 8:52 am Maybe we can combine bumper material and two-wheeler dollies made from junk around the house into one thread.

Dollies? Here are two:



What about doilies?



arp "not helping" thark

Brother, you expected us to stay on topic?

This is my nightstand in it's current configuration.
How many ways can you guys come up with to ridicule and degrade this potpourri of crap?



With apologies, I won't be able to troll you folks after 8:30 CDT.
I have to be in Memphis ready to rehearse tomorrow morning at 7: 15 A.M.. It's an hour drive, and it takes me 45 minutes to become a semi-functional human being prior to operating a motorized vehicle.

The viewers wrote:What's that brown book with the large off-white letters barely peeking out from under those soon-to-be-discarded sets of bass guitar strings?

Okay okay.OKAY...
SINCE YOU INSISTED:



... And what's on TV?


The little dual-fan thing (left size of the picture) blows additional A/C or heat from the HVAC floor vert (other side of that window) into this room.
Why are their WINDOWS between these two rooms?? Hey, ask the people who built this place...not me.