Re: [PSUBS-MAILIST] Pressure Compensated Trolling Motor Question

["Dan H." <JMachine@adelphia.net>]

Brushes don't wear down that fast.  True the dust will become suspended in
the oil, but a periodic oil change will take care of that.  The added drag
on the motor because of the churning of the viscous oil and the floating of
the brushes on the commentator bars are more of a problem.  Heavier brush
springs will help the floating.

Dan H.
----- Original Message -----
From: "Michael Wright" <mwright@smallip.com>
To: <personal_submersibles@psubs.org>
Sent: Thursday, June 26, 2003 4:26 PM
Subject: [PSUBS-MAILIST] Pressure Compensated Trolling Motor Question


> Hi Everyone,
>
> I have a question for anyone using Liquid Compensated Trolling motors.
>
> I've heard that the drawback to them is that the carbon dust from the
> brushes goes into suspension and eventualy causes a ground fault to the
> case (or direct short if no ground fault detection is used).  This seems
> quite plausible with the simple solution being to change the
> compensating fluid regularly.
>
> The quesitons I have are: Is this a problem worth solving in a better
> way?  Is the particle size large enough for an automotovie oil filter to
> catch them?
>
>
> The trick I think is to use a drill powered oil change pump to circulate
> the compensating fluid through the filter.  Since the pump has no motor
> and no air spaces it is pressure compensated by the thruster fluid.
> Cycling the full volume of oil through the filter would take less than a
> minute and could be done with a cordless drill (safe and expendable).
> Since the compensating system stays closed there is no mess and no need
> to bleed the air out of the system.
>
> So that's the idea.
>
> mike
>
>