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After 28 years of public teaching, I thought I knew all the tricks of taking apart rotors and putting them together in any situation, including doing it FAST so a student can continue his lesson, but I had never experienced bearing caps that wouldn't budge with a simple tap tap like Joe described. That was a first for me, to have to hit it so hard that I risked bending the post.
Normally my concern is to not mess up the top of the spindle post, which is why I always tap with the screw in place
should be obvious but...
The more force required to free the bearing (by hitting the stem and transferring the force through to rotor body to the bearing - overcoming the friction against the casing), the more accurate and centered must be the blow to the stem.
...thus the "elbow against the rib cage" tip.
In 5 years playing myself, one has never let me down and I find quite as reliable and no more noisy than on my very expensive B&S Neptune. I really think very few customers have problems, but the few that do are quite vocal about their problems, understandably.
What I will work to do is to turn those with problems from a few - to none as far as is possible.
I don't understand people's dislike of the lightweight linkage. If the rotors turn smooth, those linkages are under little stress and surely less weight in the mechanism is good unless they are to withstand abuse in schools?
With some made-in-China tubas...
The (apparently) M3 x .5 threading on the linkage arms themselves seem to be sloppily cut (aka "loose tolerances").
Yes, the arms will thread into the miniature links without "stripping", but (as the threads are not as tight-fitting as they could be) tend to work their way loose easily.
The small links aren't so bad, but don't have any guide springs to prevent them from rocking to either side and clicking.
I've had BETTER luck with the small links with action arms that I made myself, with more tightly-fitting male M3 x .5 threading on each end.
Also, the female threading on the knurled lock washers (same thread size) tends to sport slack in the fit, which is another reason they tend to work their way loose.
Realize this: These assemblies are impacted thousands upon thousands of times. It requires a really excellent machine fit at every possible point of these assemblies for them to NOT work their way loose after all of that...well... s.o.p. abuse.
Though the small links work fairly well, the fact that they are small means that they rotate faster across the sealed bearing ball in the center...which means that they will wear (again: eventually clicking) more quickly...JUST AS 12-inch tires have a tendency to wear more quickly than 17-inch tires.
Issues with the rotor assemblies themselves have been discussed thoroughly enough that further review would be redundant... Clearly, they move, but clearly, they are not Miraphone.
The fit of the stop arms to the rotor stems rarely seems to be precise, and there seems to be heavy dependence on a tight center screw to prevent the rotor stems and stop arms from making noise against each other...YET the center screws supplied tend to exhibit brittleness, and when tightened REALLY tight (to prevent any possibility of noise), there is a great risk of their heads breaking off their threads (leaving the hapless noise-eliminator-person with a screw-threads extraction job).
Someone asked, so I answered. It's that simple and that complex.
The lower-cost Chinese tubas that I've seen certainly are not "thin" (and btw...a really well-made "thin" brass instrument is MUCH more difficult to fabricate than a "thick" one...so I would encourage people to stop associating "thin" with "cheap"), and many of them (depending on the model, just as with more expensive tubas) sound pretty nice and play pretty well (some: very well) in tune. ...some (again, just as with other-than-Chinese and some expensive tubas) not.
All of that being said, I think $1500 - $2200 4-to-5 rotor tubas (after shipping, importation duties, marketing, ground shipping, loss from damage, personnel wages, business taxes, advertising, insurance, etc., etc., etc...) that tend to work ok most of the time is dirt cheap. I don't think anyone could have any sort of reasonable expectation of anything better at this price point. With no insult intended, think: Harbor Freight. If Harbor Freight stuff didn't work at least fairly well, no one would be buying any of it. ...but I don't believe anyone who buys Harbor Freight stuff is under the impression that it is anything more than what it is.
Are there some factories in China that seem to generally do better fabrication work than others? I'm sure there are...and higher pricing goes right along with it...and (as "made in China" and "NOT dirt cheap" still seem to an incongruity to many westerners) the higher-priced and more-made-with-care made-in-China instruments tend to be slower sellers.
bloke "What's the big deal, here?"
Joe, I look forward to talking with you at ITEC where you might explain further to me as a less technical man than you
Jonathan, can you confirm that the current models of Prague tubas do not have valves that look like this, and if not, why does mine? I took this photo on the first day my tuba arrived, this is the way it arrived. Nothing is bent, it's just the linkage arms are too short
I will need to check one in the store, as can't say if that is normal without looking. I know the Prague has rather unusual paddle angle which some people like and some don't.
EDIT: I confirm that the angle is quite normal
Last edited by Wyvern on Sat May 28, 2016 12:08 pm, edited 2 times in total.
After living with it for 6 months, put me in the NOT column
I could add longer rods, but I'm waiting to see if I wind up replacing the entire linkage assembly
Two of these should be plenty to cut and bent four action arms to whatever length you could possibly want.
Hopefully, the threading is cut pretty well.
If you don't like the look of all-thread, here's some black shrink tubing to cover up the exposed threads:
I've used stainless steel tubing to cover the all thread before, it looks really nice
I have today been in meeting with the Production Manager at factory and had a detailed discussion about the rotary valves and the problems Mark has experienced.
Apparently in the last year the rotor head has been completely redesigned, and is now tapered so as it is pushed down forms a tight fit around the spindle, so any slack and resulting noise has been eliminated. It no longer relies on over tight screw. Secondly the actual screws have been changed from being made of brass (soft) to stainless-steel (hard), so there should be no future problems with broken screws. The minibal linkage has also been redesigned to stop the flopping of linkage and the actual minibal itself is being replaced with more robust version to last better over time.
In collaboration with Wessex, there is a major drive here to raise the quality standards in every area. During the next week we will be carrying out audit of every area of tuba production from the making of individual components to final assembly and finishing, to highlight where improvements to quality control can be made. Whenever we find a fault during our quality assurance checking, it is photographed (where applicable) and noted to be taken back to the relevant area to ensure will not re-occur in future.
So far we have quality checked over 70 euphonium this visit and problems have been confined to one poor joint (resoldered), one misaligned valve, one leaking water key, and two cosmetic blemishes. So standards are certainly improving and quickly too.
Last edited by Wyvern on Mon Jun 13, 2016 9:17 am, edited 1 time in total.
That was the first thing I noticed when I played one.
Who needs four valves??
It is very good to see that progress is being made to improve the mechanics of the WESSEX tubas. However.... can one assume that from this point forward the rotor parts on WESSEX tubas (and I suppose others made in Asia) will not interchange?
"The Village Tinker"
Current 'stable'... Rudolf Meinl 5/4, Bohm & Meinl helicon, King 2341, Alphorn, BBb cimbasso, and misc. other strange stuff.
This is why I don't order made-in-Taiwan parts from that "planetary" company's online parts list (not to mention that I've NEVER been able to log in to that site successfully). I send pictures-with-arrows and serial numbers to "a guy in Nashville" and let them figure it out.
I don't think it is possible to generalise on interchangeability of parts, as that will depend on the change. It may mean change of certain parts on older tuba means change of mating part where there is redesign, in which case there will be no extra charge for the additional part.
Jonathan, I can't believe I forgot to do this at ITEC, but could you post a pic of the new linkage that wessex is offering? (either on this thread or where ever you think it would fit the best)
I know you don't want to get into the parts business, but if the new linkage is such an improvement over the old, It would be nice to make available for purchase the new linkages to existing customers of wessex who bought tubas with the older design.
I'm going to change this linkage to get rid of the weird angle of the valves. The question is if I'm going to make the linkage myself from hobby shop parts, or use actual instrument parts
Looking down the section a community band rehearsal last night, I noticed that a section mate's Allora "186" BBb has this angle (not the curve on the end of the paddles, but the overall mounting angle.
No, I don't really have a point other than that the Prague isn't the only tuba that has this.
Allora tuba = JinBao, same as Wessex, etc.
Mark's tuba is the result of parts bin syndrome, too.
As far as poor bloke's broken heart and all his *sighing* goes, I never have trouble interchanging parts on any Yamaha instrument nor any Jupiter instrument.
I guess I'm just lucky.
Sometimes you can't make a sow's ear into a silk purse because there just isn't enough ear.
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