[PSUBS-MAILIST] Minn Kotta 101 - Thruster Reliability

[Jon Wallace via Personal_Submersibles]

 All good points Sean.  I wonder if we should try to write a project plan although I’m not a fan of too much formality.
Jon


    On Thursday, July 27, 2023 at 09:58:46 AM EDT, Sean T. Stevenson via Personal_Submersibles <personal_submersibles at psubs.org> wrote:  
 
 Perhaps performance targets would be a more appropriate community standard, as opposed to a particular physical embodiment?

I'm thinking specifically of the ability of an air compensation system to keep up with maximum descent rate, to vent sufficiently quickly at the maximum ascent rate, and to have sufficient HP compensation gas in reserve to accommodate some prescribed minimum number of dive cycles, as we do with ballast tank air.

For oil systems, attention to dielectric strength, accommodation of thermal expansion / contraction, tolerance on continuous bias pressure, make-up oil capacity, material compatibility, ability to vent evolved air from high points, sealability (viscosity / lubricity) against rotating shafts in conjunction with their sealing arrangements, environmental and fire hazard, and oil condition / volume monitoring requirements or periodic sampling / analysis / replacement criteria? I am aware of past problems here with oil compensation systems using "flexible" tubing elements which don't collapse immediately, so perhaps a responsiveness / pressure tracking criterion?

I'm a fan of the design paradigm of using any single seal to change fluid, or to change pressure, but not both. That doesn't work for everybody. I'm not sure a "one size fits all" hardware solution is necessarily the answer here, but it certainly is worth having the discussion.

Sean

-------- Original Message --------
On Jul. 27, 2023, 07:32, Jon Wallace via Personal_Submersibles < personal_submersibles at psubs.org> wrote:



I would like this group “think tank” to come up with a viable and accepted solution for all compensation modes; air, oil, and 1-ATM.   It would provide a known standard to build to while still allowing for enhancements by those who want to try other alternatives.  I’m sure that all of collaborating on this project will end up with good results. 
Jon_______________________________________________
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