BART reborn (almost)

[MartyNeilan]

BartPistonFront.JPG

Yes, my soldering is beyond sloppy, but all the parts fit togther very well. I still have to make the 5th valve loop (got it all mapped out, probably just adding two short curved bends to the previous first slide) and linkage (wish me luck on that), but everything else is ready, sans adding another brace or two.
I had to move the former fourth rotor down and tilt it in order to have the pistons in an ergonomic position; keeping them directly inline with the old rotor would have placed them too far over on the horn for anyone with less than gorilla arms.

BartBackValves.JPG

The back view shows the dogleg and the repositioned rotor.
In its previous incarnation the horn played up to 440 cold after extensive cutting (note the very short tuning slide) and still does after the conversion. Pitch tendencies are similar to before or slightly improved; I "fixed" a number of little things I found in there. Slots seem a little wider than before. The horn sounds great; a little more "American" than "German"
More details to come eventually....

Jacob12JandPistonBart.JPG

Here is a comparison of the massive tuba formerly known as BART next to my son's 12J.

[k001k47]

cool!
Looks like an oversized 2145.

[rodgeman]

Great job! Can't wait to see it complete.

[tclements]

WOW! How cool is THAT?!? I'd LOVE to give that sucker a honk!!

[TheHatTuba]

Looking good! Hard to believe the bell's diameter given the constant taper.
Just outta curiosity, why did you swap the valves (old ones worn, dislike rotors, etc)?

[MartyNeilan]

cool!
Looks like an oversized 2145.

More like a cross between a PT6P and a 2165 since it is in the 5/4+ 6/4- category.

Re-examining it, I think they do share some similarities in the overall taper, just to a different magnification.

[MartyNeilan]

Looking good! Hard to believe the bell's diameter given the constant taper.
Just outta curiosity, why did you swap the valves (old ones worn, dislike rotors, etc)?

At nearly 100 years old the rotors, although previously rebuilt, had seen better days (possibly excluding the lessor used fourth.)
Also, it let me rework the lead pipe and have it come around the horn, instead of sticking out to the side at 45 degrees, as it did when I acquired the tuba (most likely a previous owner's attempt at getting it up to pitch)

[arpthark]

This is one of my favorite things about TubeNet. Fantastic! I would love to give that a blow.

What did you get the piston valveset from? Looks MW-ish.

[Frank Ortega]

Sound clips , please!


Great job!

Looks like a fun horn.

Frank

[MartyNeilan]

I don't want be negative, but your horn has one of the same problems as many Franken tubas; improper tuning slide length.
Many Bob Rusk tubas have three inches or less and so does my clear horn, but this is not practical. The reason this doesn’t mater
with huge concert hall horns is simply that they are for indoor use only and the temperature range their in is narrow, but if you
get into a cold room or outdoors or just a group whose idea of concert pitch is out of line....... it sucks !
My horn is usually right to the end of the slide sharp.
Now because I don't see where you can gain length from, I can only say good luck I hope it doesn’t become a problem.

Unfortunately, the horn was basically like that when I purchased it in its four rotor configuration, and it still played a little low. The inner bows had already been cut a lot as well, so no option to do a "Fletcher cut." I did shorten the tuning slide about another 3/4" total on each side (two different trimmings) and trim in a few other areas on the main bugle (the big end of leadpipe and dogleg before the tuning slide), to get the instrument to reliably play up to 440 with a large mouthpiece and when slightly cold. I also had to chop several of the rotary valve tuning slides for intonation. The horn then played consistently at pitch before I undertook the conversion project; if the horn was out of tune before it would still be after.
Although the slide only has a couple inches travel, I have rarely had to pull the slide more than 1/2-3/4" even with a smaller mouthpiece and usually have it between all the way in and 1/4" out.
I have not played any outdoor 100 degree gigs with this horn. My contingencies for that are using a sousaphone bit as an extender or possibly fabricating slide extensions for it someday. The problem I run into more often is places being over-airconditioned, hence the short slide.

[GC]

So, now you have a Big A$$ Once Rotary But Now Piston Tuba (BAORBNPT). Just rolls off the tongue, doesn't it.

Better acronyms are always appreciated, though . . .

[MartyNeilan]

Now that I have finished a flurry of activity, I have started working on this project some more. The horn has played well as-is, but changes have been needing to be made. I angled the rotor further in and made some other tubing changes to bring the piston cluster about 1 1/2 inches closer to me and also angled it slightly. This will greatly improve the ergonics of reaching around a tuba with such width. Right now, the leadpipe is sticking way out, Butterfield style. I will rebend it this weekend to allow it to further come around the bell, completely eliminating the off angle nature of it. The leadpipe was originally in about a 45 degree position when I first got the horn, and was able to bring it about halfway where I needed to with my last major work - moving the pistons closer to the bell side of the horn will give me the necessary length to finish wrapping the pipe around the horn.
Once I am 100% satisfied with the piston and leadpipe position, I can finally start plumbing the 5th valve. I have been holding off on that, because I did not want it getting in the way of things. Some of all of the firth valve tubing will occupy the space the Joe pointed out.

[Tubajug]

I'm probably just ignorant, but I assume this is a CC tuba and not a BBb? Just curious, and great job. I would love to be able to build my own horn someday just for the fun of it.

[MartyNeilan]

Now, it actually fits me!
I have the valves situated where I can reach them with my 33" sleevelength arms and slightly angled to allow my wrist to be completely straight. The leadpipe now comes completely around the horn as it should, so the tuba is held parallel to the body and does not poke me in the stomach anymore. (I heard a college kid got a great deal on a big horn once because of a similar issue.)

I may tweak a couple of things and may also lower the leadpipe a tiny bit more, this should be possible without rebending it.

In response to other questions, the horn was most likely once a BBb when it was made nearly a century ago with 4 rotors. It was cut to nearly CC some years ago and the valves were rebuilt. Part of this cutting included the leadpipe, which came only about 45 degrees around the horn. I was able to trim a little more off the main slide and valve slides to get the horn to play in tune with any mouthpiece at any temperature shortly after I got it. Last winter I purchased a MW "small piston" valveset that came off a first generation 2165. With enough creative cutting and bending, I have the original fourth valve relocated to be the fifth rotor and the piston valveset grafted in. The original leadpipe was shortened to where it tapered to the correct diameter to fit the piston valveset and then rebent. The latest set of work was more of a fine tuning and tweaking to get the horn to fit me better, instead of trying to make me fit the horn. Once I am 100% sure of the final valve layout, I will install the tubing for the fifth valve using parts off the original valveset. I will also replace the 3rd and 4th valve water keys with Saturn water keys, I had one installed on the main slide and love it. Longterm work includes eventually replacing the many times cut main tuning slide tubes with new tubing and possibly a 45SLP leadpipe and receiver. I have so far done all the work myself, except for having Joe Bloke refit the 1st piston and install the Saturn water key. I may look into having him add a kranz to the bell someday, to reinforce the thin metal.

I forgot just how big this tuba was! I had my wife snap this picture last night after the latest rebuild! (Granted I am not the largest tuba player by any stretch.)

[TubaZac2012]

This thing is rad!

[eupher61]

Marty, now that it's 2 years later, what's your opinion of it? How about some dorn of the finished product now?