Posted by Ken Herrick on July 09, 2002 at 01:36:19:
In Reply to: Rotary Repair Question posted by Andy Smith on July 08, 2002 at 21:22:31:
PLEASE!!!!!!!!!!! Do not try pushing the rotors out by tapping on the retainer screw as it there is anything more than the slightest resistance you are likely to distort the threads or worse.
I DO NOT recommend these aerosol lubricants either as they are likely to gum things up and cause you more problems and even necessitate a chem clean.
Get a flat tipped punch which fits inside the rotor stop arm and gently tap on it making certain it sits squarely.
The best advice I can give is find a repairer who KNOWS what to do and will let you watch how it is done properly. Make a booking and expect to pay a fair price. I have had to repair MANY rotory valve instruments which were damaged by incorrect servicing.
The fact that your valves seized indicates that they were not well lubricated. Well fitted valves which have been oiled properly CAN sit for years and not seize up. If there is corrosion building up between the rotor and casing you may need more work done, ie lapping and a good thorough clean after. Oil not only lubricates, it acts as a corrosion inhibitor.
There is also the possibility of a foreign body having gotten in. Not long ago a trombonist friend mentioned to me (on the bus on the way to a competition) that his rotor was jammed half open and no matter how hard he tried he could not move it all the way open or shut. Had to turn the bus around so I could grab an emergency repair kit. There was a staple jammed between the valve and casing. He was lucky we had an overnight stay before the comp. Just wish I had been able to go out on the town with the rest of the group instead of doing a freebie repair job in the hotel. (How's that for "nuisance jobs JS??)
I know it is a burden for a student to have to pay for instrument repairs, but paying an expert can save you a lot in the long run (or even short term if you botch the job.)