Suggestions for a line release mechanism, please ?

[Externet]

Hello all. New here and impressed by your work.

Looking at the web for varied mechanisms, found this forum with lots of skills and experience.
Am after a cord/line/string release mechanism and would like your suggestions.

The intention is to release a string length tied to a float that would reach surface on command. The 'bottom' end of the string having a ring, the 'top' end of the string a buoy. The assembly carried underwater until released launching the float upwards with the string hanging below.

A simpler way to explain... You are at your backyard holding a helium balloon by a ring at the end of its string. Release it.

If possible, the actuator for the release mechanism inside a hermetic chamber. (Trough wall action with no openings)

[He Who Shall Not Be Named]

Solenoid actuated bell-crank in the wet.

David

[Externet]

Thank you. Do you know if an assembly of a wet bell-crank driven by a dry solenoid is available somewhere ? Or is it a do-it-myself ?

[He Who Shall Not Be Named]

Thank you. Do you know if an assembly of a wet bell-crank driven by a dry solenoid is available somewhere ? Or is it a do-it-myself ?

It's a do it yourself. Find a DC solenoid that works off the voltage of your main power supply; put a boot type seal between the solenoid body and actuating slug; slather the entire unit in silicon sealant, and you have a water-tight unit.

Here are some water-tight seal options for you:













David

[Externet]

Thanks again, good clues.
I was aiming for the magnetic field to actuate the bell-crank trough a sealed dry chamber wall (no holes at all) but seems I should settle with a bellows. The solenoid pulling a plate inside the bellows end and the bellows outside to do the triggering. Will refine thoughts... I should be careful with a sealed bellows to not collapse at depth and produce unwanted movement.

[trout]

Maybe a electric magnet. When your batter dies it releases the buoy or failsafe cuts off power.

[Scott T]

David did create this magnetic coupling on a Subdriver.

https://forum.sub-driver.com/forum/general-topics/2921-ballast-tank-equipped-1-25-subdriver-now-in-production