RE: Trolling Motors

["Morrisson, Richard D" <Richard.Morrisson@PSS.Boeing.com>]

Ken,

Thanks for your response, especially the part about being "sharkbait".  I
might just go the extra mile (miles?) and make it a wet sub, I'll provide
updates as things develop.

Dick Morrisson

> ----------
> From: 	Subscuba@aol.com[SMTP:Subscuba@aol.com]
> Sent: 	Thursday, October 22, 1998 11:54 AM
> To: 	personal_submersibles@psubs.org
> Subject: 	Re: Trolling Motors
> 
> Hello Richard,
> 
> I talked to a design engineer at Lake Motors located in , I think in
> Chicago.
> Unfortunately I didn't keep his name or number, at that time I wasn't on
> this
> mailing. I had to call Minnkota to get his number and I was told by
> Minnkota
> that the Motor I'm using was made by Lake Motors. I don't know if they
> make
> the motor you are trying to use but I would suspect so. The engineer at
> Lake
> Motors was a little reluctant to talk to me and release a lot of data. I
> think
> he was afraid of impinging on proprietary issues. Any way he gave me the
> following:
> 
> 1) The motor shaft is indeed made of stainless steel, the engineer seemed
> to
> think the steel was not a high grade of stainless steel but much better
> than
> the normal rust enhancement steel used on my boat. The problem with making
> the
> motors for use in sea water is that the housing has to be made of a
> readily
> magnetized steel since the housing is part of the magnetic path. This can
> mean
> rust enhancement steel and must be protected from the corroding effects of
> sea
> water by painting. The motors Minnkota offers for use in the marine
> environment have a pretty durable coating but still will degrade. They
> also
> have to cover themselves from incurring extra cost by warranting the
> product
> only for their market. If you use their motor as I am doing it will be a
> constant effort to prevent corrosion. I plan to keep a lot of grease
> (Vaseline) around the motor shaft along with touchups to the motor paint.
> Compared to the other problems this is not major unless you let it get too
> far. Painting an additional coat or two of a two part epoxy paint would
> also
> help, assuming compatibility with the existing paint. I once heard rumors
> of a
> stainless steel motor but couldn't find a vendor. I suspect I couldn't
> afford
> one anyway.
> 
> 2) The electronics will be very prone to sea water damage as well you
> know.
> Coating the Circuit Card Assemblies with epoxy will help minimize the
> problem.
> Total flooding will still tend to wipe out the controller especially with
> power applied. 
> 
> I would be interested in what you may use for your pressure compensation
> with
> a deadband of pressure. I'm not completely happy with what I am doing
> since
> the positive pressure depends on having the SCUBA regulator always at a
> lower,deeper, point than my air spaces. What happens when I turn upside
> down?
> Bear in mind I have a Wet Sub as I intend to do small excursions outside
> the
> Sub plus I can easily bailout. Maybe no excursions if some of the critters
> I
> have seen are bold and/or hungry. My maximum design depth is 480 feet and
> is
> limited by my floatation. That's  much deeper than I intend to go.
> 
> Good Luck with your Diver Propulsion Vehicle. If you scout around you may
> find
> some divers are not happy with them. There is one individual in Calif. who
> was
> attacked by a Great White and feels the sound of the scooter he was using
> played a part in making him bait. He did survive, just had a lot of scars
> and
> stitches. He had an account of the incident on the Internet for a while.
> 
> Have fun,
> 
> Ken Martindale 
>