Merry Christmas!
This afternoon I worked on the 5th valve section again. I finally (no, really, I promise this time — FINALLY) Got the double knee dialed-in to work with this tuba. I do not think the genuine part from Miraphone would fit this horn without some modification. It turns out that my valves are a bit too close to the bugle where the lower slide tucks behind them. It is an almost impossible problem that you cannot see and that I do NOT want to have to tear the whole valve section off again to fix. I came up with a part that fits the 5th valve while clearing the 3rdh slide tube BUT THAT BENDS BACK TOWARD THE VALVES to allow the stock crook to stretch far over enough to meet the dogleg from the upper slide. There are four very important clearance points you *must* have set up correctly or the lower slide will be trapped in place and two rear valve caps cannot be unscrewed.
After four tries I came up with just the right needed angles and lengths with usable radii. I am GLAD that part is over.
I wired together everything to check these clearance points, and two are *really* tight, but they work, and that's all that she wrote. This gets soldered on tomorrow afternoon.
In the photos, I accidentally pushed the lower slide a bit, so the angle from the dogleg to the lower slide is wrong-wrong-wrong, and did not see it until the pics were taken. I am done for the day, so even though this has been corrected, you get to see it wrong-wrong-wrong. (You lucky dogs!)
Here are some pics. Yes, this is shorter overall than the actual set of Miraphone parts, but this is because I added 3.5" to the overall length by using the wider crook and the J-shaped part to allow me to be a cheap-a$$ and not purchase a new valve. Keep in mind that I have been remarkably cheap with this horn, where I have lavished stuff on the factory CC. The reason is that I have played the factory CC as my main orchestra horn for a year and loved it. To me, it is a proven work tool that makes me enjoy what I do. THIS tuba was a complete unknown. It had holes and cracks all over, and even without the damage, it might have been a bowser. I had to not only get it playable, but I cut it to CC from BBb, so anything I spent on this tuba could have easily ended up being wasted money. It turns out to be an excellent tuba, so I might eventually lavish some German-made love on it; it certainly plays well enough to deserve most of what I spent on the factory CC. Of course, pimping it out removes the novelty of my having hacked up so many useless parts to serve in new roles. As weird as my 5th branch, 4th, and 5th slide circuits might appear, THEY WORK REALLY WELL. I think there is value in that, itself. So maybe I will just fix the bell garland that I did such a mediocre job on.
The project to restore and pimp out my beloved factory CC 186 was huge and a lot of fun. But it was just stuff I have done for years. THIS horn, however, is a whole other deal. I have never done some of this work, nor have I ever done this much custom work along with so much big-ticket repair work on a single instrument. Not only was this project fun, but it was hugely educational.
… and here's that good hornporn…
This 5th valve unit came out really well for it being such a cobbled-together "kludge". I am not unhappy with my results.
The red circles are crucial clearance points.
The red circles show the homemade fixed braces I silver soldered together today. I still have to make two braces that pin the lower, inner slide leg to the 4th and 3rd slides. (I have to make these two for the other 186, too.) I also have to make one of the funny braces used between the upper slide and the leadpipe for the side that is close enough to use one.
Glad I caught this. I would not have wanted the very nicely aligned slides to have been under this sort of stress all night. That would have been bad. As it is, I need to recheck the alignment, now. Rest assured that I did fix this and that all the clearance points are still good. :-/
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