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

["Captain Nemo" <vulcania@hawaii.rr.com>]

Roger,

I know the torquing of these cases is pretty light and sensitive; I'm
wondering what the pressure would actually do to the way everything fits
together, and how things turn inside.  I sure hope you and Phil get together
and do that pressure test; it would really be worth it to all concerned.

Pat
----- Original Message -----
From: <rjune@fuse.net>
To: <personal_submersibles@psubs.org>
Sent: Thursday, June 20, 2002 7:59 AM
Subject: Re: Re: [PSUBS-MAILIST] external Motors for depths of 1000ft


> 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
> >
> > From: Rob Innes <innespace@jett.net>
> > Date: 2002/06/20 Thu PM 01:40:42 EDT
> > To: personal_submersibles@psubs.org
> > Subject: Re: [PSUBS-MAILIST] external Motors for depths of 1000ft
> >
> > Herve
> >
> > On your Caribsubs, do you run your motors variable speed or are they
just 36V
> > on/off, with no rheostat?  I presume not all four thrusters can be used
for
> > forward thrust so what speed will they cruise at with the forward
thrusters.
> > Did you say they are factory rated to 140 feet or has this just been a
trial
> > and error depth testing on your part ? Has anyone destroyed a factory
> > unmodified trolling motor by taking it too deep? Thanks for all the
input!!!
> >
> > Rob Innes
> >
> > Herve wrote:
> >
> > > i attache 4 motorguide 107 lbs on my subs, pretty powerfull, i usually
run
> > > them at 70 %
> > > They are pressure comp, for no deeper than 140 Ft you dont need to
fill them
> > > up with oil.
> > > Herve
> > > ----- Original Message -----
> > > From: "Rob Innes" <innespace@jett.net>
> > > To: <personal_submersibles@psubs.org>
> > > Sent: Wednesday, June 19, 2002 4:03 PM
> > > Subject: Re: [PSUBS-MAILIST] external Motors for depths of 1000ft
> > >
> > > > Does anyone know how much resistance is caused on the trolling
motors by
> > > > filling them with the oil? Approximately how much thrust could
expect  to
> > > be
> > > > lost on a Motorguide 107lb thrust unit? Has anyone fitted one or
more of
> > > these
> > > > motors to a sub or DPV?  I'd be very interested in the results
> > > >
> > > > Rob Innes
> > > >
> > > >
> > > >
> > > >
> >
> >
>
> Roger June
> REJ and Company
> rjune@fuse.net
> 513-300-1189
>
>