Jul 19, 2025
Rotor from a Hirsbrunner tuba. The delrin insert is to reduce weight.
#musical instrument repair#music#brass instrument#brasswind#musical instrument#tuba#Hirsbrunner#rotary valves#I *think* the little circles visible on the outer surface are from a rod through the brass into the delrin to hold it in place#but I'm not 100% sure on that because this is the first time I have seen these in person nor have I seen a cutaway diagram