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

[rjune@fuse.net]

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