The top-range bassoons, particularly older ones, use ivory as a material for their bell rings. Due to regulations this can make international travel difficult as many countries now have strict laws in place regarding materials such as ivory.
This 1970’s era Heckel Bassoon fell into this category and the owner requested we remove the ring. After contacting the factory it was made clear that the ring can only be removed through machining and unfortunately cannot be removed as a solid piece.
The photos below show the process. Using a 4-jaw chuck and a dial indicator, we made sure the bell spun within 0.001″ run-out so the ring was removed as concentric as possible. We were also most happy to make a replica ring for this instrument, but it was being shipped back to the factory for an overhaul so this was not required in this instance.