RE: [PSUBS-MAILIST] Troller motors

["Helmandollar, Troy A" <HelmanTA@bp.com>]

I wasn't going to run it in a pod. Just tap into the original housing with
the balance line. The housing already has a seal that holds out water.  Or
am I slill way off base.

-----Original Message-----
From: Dan H. [mailto:JMachine@adelphia.net]
Sent: Monday, June 30, 2003 4:24 AM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Troller motors


Troy / Brian
As you noted, you can't just run a sealed bearing, but there are proper
seals available.  Depending on the depth you are designing for, there are
several seals available.   Even a simple O-ring will work, although it's
life is not long.  For most subs in the Psub range, a carbon and ceramic
pump seal will work well.  They start at around $10 US and go to around $40
US and are a bit bulky.  Most water pumps use them.

Motors in sealed pods with carbon ceramic seals is the method used on a
K-250, K-350 and K-600.  (to 600 feet of depth)  I don't think you can just
put a trolling motor in a pod though.  Trolling motors are physically quite
small for their power output.  This tells me that they require quite a lot
of cooling.  When submerged in water, the water acts a large heat sink for
these motors.  If placed in a pod the pod jacket would stay cool but I fear
the motor inside will get quite hot and burn up not being in direct contact
with the water itself.  You should probably contact the motors manufacture
about its cooling requirements.

If designing a motor in a pod, it must be a motor rated to run in air, at
the voltage, and with the load your prop is applying.

Good luck, Dan H.

----- Original Message -----
From: "Helmandollar, Troy A" <HelmanTA@bp.com>
To: <personal_submersibles@psubs.org>
Sent: Monday, June 30, 2003 2:15 AM
Subject: RE: [PSUBS-MAILIST] Troller motors


> I'm not sure but sealed bearings don't handle much pressure. How much, I
> don't know.  I was thinking of just using a used troller motor and just
tap
> into the case with the balance line.  The advantage of using the troller
> motors that I can see is that you get all the controls for them.  As far
as
> electrical penetrations go I just made my own last night using a
stainless
> fitting that had a shoulder inside filled with epoxy.  I stripped two
solid
> wires and stuck them through the fitting.  I tested the fitting to 2400
psi
> with a hydraulic enerpack.  Held fine.
>
> -----Original Message-----
> From: Brian Cox [mailto:ojaibees@ojai.net]
> Sent: Sunday, June 29, 2003 7:46 AM
> To: personal_submersibles@psubs.org
> Subject: Re: [PSUBS-MAILIST] Troller motors
>
>
> Hi,  Can't the motor be encased in it's own 1 atm. vessel and the shaft
run
> through a sealed bearing?
>
> Brian
>
> ----- Original Message -----
> From: "Helmandollar, Troy A" <HelmanTA@bp.com>
> To: <personal_submersibles@psubs.org>
> Sent: Sunday, June 29, 2003 2:51 AM
> Subject: [PSUBS-MAILIST] Troller motors
>
>
> > This might have been discussed before. But I am wondering if anybody has
> > used a sensing line from the top of their trim ballast to pressure
> > compensate their motors.  This way it is all done automatically.  The
only
> > drawback that I can see is water getting into the sensing line.  This
can
> be
> > mitigated by positioning the blow down line well below the sensing line,
> so
> > the water doesn't reach the sensing line.
> >
>
>