Very tight tolerances on miraphone 289 rotors.

[Beans&Tuba]

After 6 or 7 years of playing 3 nights a week in local bands, I decided to take apart a perfectly good tuba to clean it . I have removed rotors several times on some of my older tubas, so I thought this would be no different . The first thing I encountered after driving out the back bearing plate is that the rotor had to be driven until it was completely out of the rotor casing. After cleaning the horn in the tub when I tried to put the rotors back into place , I noticed I have to drive the rotors back into the bearing casing. It is like this on all 5 rotors. I cannot believe the tolerances are this tight. I have an appointment with my repairman today so he can show me what I'm doing wrong but can't imagine what it is.

[Beans&Tuba]

I noticed that when reinstalling the rotors ,I typically could drop the rotor (after oiling the stem) back into the casing ,and then drive the back plate back on. Not on this one .The rotor will not drop back into the casing. It has to be driven in, and then the end plate driven back on .Could these chokepoints be on the top bearing surface as well.? By the way Joe, my blokepiece Symphony Works excellent on this horn .thank you.

[Beans&Tuba]

Crisis averted . The rotors are back in and working properly . The technicians experience was invaluable . Joe, I believe it was everything that you'd said and the technician said he sees this all the time with the newer miraphones. The only problem that Still Remains, (and I told him don't worry about it at this time )was one of the pointed adjustment screws in the rotor cap was stuck and would not come out and could not be adjusted. It's not a problem now because I don't have any end play on the newish rotors .

[Beans&Tuba]

I also had the main , and 4th tuning slides expanded because they were constantly trying to fall out . You'd think at what this thing cost when I bought it new, that more attention would have been paid to the tuning slides. Acid bleeds p!$$ me off also. Good thing it plays fantastic !

[Beans&Tuba]

Especially since both of those slides are vertical .