Re: [PSUBS-MAILIST] external Motors for depths of 1000ft

[MerlinSub@t-online.de (Carsten Standfuß)]

rjune@fuse.net schrieb:
> 
> Both Minnakota and Motorguide motors are factory warranted
> to a depth of 33 feet.
> If you use them deeper than that (without modifying them) than you are
> relying on the shaft and body seals to hold back the pressure.
> Because the body seal is a static o-ring seals it will easily hold
> back 400 to 500 psi (equivalent depth of aprox. 1000 feet).
> As to the shaft seal, as the pressure increases the friction between the
> seal and the rotating shaft increases.  Once the seal wears a little it
> will start to leak.  After enough water gets into the motor, the motor
> will start to corrode and eventually short out.
> 
> Roger

On Sgt.Peppers I have as maindrive a Minn Kota - air pressure compensate
with a normal Scuba regulator. Ken M. can explain better than I - in
your 
language - how its works. One dive day two years ago the connection
between 
the pressure bottle and the regulator was missconected.
Lost the air. Motor was filled with lake water (freshwater) - I realise
during the dive that it turns slow - no flash or short securit - still
works - I am pretty shure you lost 20-25 %& efficentcy with a oil filled
thruster. I dry it later and it still works up today ..

The first version of the main drive was a car engine starter - oil
filled - but was filled 
with car motoroil - and did'nt start after longer stop periods - later I
filled the engine with a oil (Terpentin) very simillar to petrol - the
engine runs well - but the cables plastic gets hard and break.. Last
version was air compensation for all thruster and batterys - works well
- but keep care that the pressure bottle is well connected..  

Update for friends : Freya is destroyed by lorry accident - very sad but
maybe can repair,
sail goes 3-4 inch into the pressure hull during the accident. Just the
midship section has 
to be replace..
CSSX interior stainless steel frame work on walls and decks structure of
diver chamber and control room are done.. Get pretty hot inside the hull
if the sun is shinning.. 
So hot that you can not grab the frames on the top inside the hull !
Stop working and waiting 
for bad weahter and rain .. 

Solutions are one thing - - - expirence an other. 

Best regards Carsten, Germany