I agree with your comment about filling with another compound.  For example
Shell Diala is a suitable non-conductive light oil that is used in electric
company transformers and will double as dummy load oil.  I found that it can
be purchased locally very easily for $27/gallon.  I found another compound
that is a natural for this type of work through my research.  A compound
called "Gelstar" is similiar to silicone grease but a fraction of the cost.
It is in the $20 per gallon price range.  This stuff is apparantly used to
inertly backfill fiber optics.  It can be used as a dielectric grease.
73,
Mike
----- Original Message -----
From: "Douglas Butler" <dbutler@IMETRIX.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Tuesday, July 31, 2001 5:48 PM
Subject: Re: [OT]: Underwater robots


> For high power deep work they use hydraulic prop motors.  There is a
> central hydraulic pump with an oil filled electric motor.  Those systems
> are usually 10 to 1000 horsepower.
> My company (Imetrix) uses electric 1/2hp to 1hp off-the-self
> magnetically coupled thrusters.  They have an electric motor & gearbox
> which spins permanent magnets in an air filled stainless steel cup.
> Magnets outside the cup drive the prop.  If we had to custom build
> something the pancake motor idea might work.  For a model the VCR motor
> might be a place to start.
>
> Sherpa Doug
>
> > -----Original Message-----
> > From: Peter L. Peres [mailto:plp@ACTCOM.CO.IL]
> > Sent: Tuesday, July 31, 2001 1:17 PM
> > To: PICLIST@MITVMA.MIT.EDU
> > Subject: [OT]: Underwater robots
> >
> >
> > > seals
> >
> > One of the easyier ways is to have normal (almost) capsulated motors
> > completely filled with light oil or safe freon. The water
> > won't try to get
> > in as there will be no pressure differential and usual seals will be
> > enough. An equalizer membrane is usually necessary for
> > thermal expansion
> > and such. The motors need to be run slower. In theory there is an
> > increased danger of explosion (not implosion) with this but
> > if you go into
> > deep water you live dangerously anyway.
> >
> > Peter
> >
> > --
> > http://www.piclist.com hint: PICList Posts must start with ONE topic:
> > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
> >
> >
> >
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
>

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads