Something that I thought up (not sure haven't seen anything like this yet I could be wrong) just wanted to post it.... as an idea for possible tube mods. Yeah I know it isn't a great drawling or done in snazzy 3d rendering etc etc.
the red parts are strong magnets reversed on eachother so they push apart. The green is the lock and the blueish is the shaft. You could even tefelon the inside of the shaft for minimal friction too.

the red parts are strong magnets reversed on eachother so they push apart. The green is the lock and the blueish is the shaft. You could even tefelon the inside of the shaft for minimal friction too.