Rotor bumper diameter for Conn 88H

[jonesbrass]

A little off topic, but I’m trying to assist a low brass colleague by replacing the rotor bumpers on her Conn 88H. What diameter do I need? 4mm? 4.5mm? 5mm?

[bloke]

Small diameter. Stuff it in there by rolling it in with a dull bladed screwdriver, and then trim it off flat to line up with the marks.

To prevent accidentally scuffing up the top of the rotor casing, take the cork plate off, put it in a vice-protected by some paper or cardboard, and roll the bumpers in once that setup is achieved.

Rather than giving you a diameter, I would say that maybe 5 mm is too big, and if it requires a bit of effort to roll it in place with the dull bladed screwdriver, that's probably just about right.

specifics?
"a bit larger diameter than the diameter of the C-shape in the cork plate. Otherwise, there's too much risk of them falling out."

[jonesbrass]

Thanks, Bloke!