[PSUBS-MAILIST] Brushless Motor Drive

[Land N Sea]

E-Mail Software 6.0Hi Brian

I just had a bow thruster put in my sailboat, per, my wife’s insistence as she was the one who had to do the leap of faith to the dock with bow and stern lines in hand, and it draws a lot of power so I had to put in a dedicated battery for it but the spec’s say that it will shut off automatically after three minutes of continues use to prevent any damage from over heating. Might want to check into that before going that direction?

Rick

From: brian 
Sent: Saturday, October 26, 2013 3:54 AM
To: Personal Submersibles General Discussion 
Subject: Re: [PSUBS-MAILIST] Brushless Motor Drive

Hi Carsten,
                       Do you need to worry about expansion of the oil when the bow thruster motor heats up?  Do you have a remedy for that?  or maybe it's not a problem because you use it only when docking.

Brian

-----Original Message-----
From: <MerlinSub at t-online.de>
Sent 10/26/2013 3:03:00 AM
To: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
Subject: Re: [PSUBS-MAILIST] Brushless Motor Drive

I did this in the past. Looks cool and second hand lower units are relative unexpensive if you purchase ouboards with damage heads - but do not work well.  

Special with a oil hydraulic forward and aft shift system it is nearly impossible. 
Needs allways a iddle rpm of the engine to feed the oil pump and to shift. 
Means you have to run forward to shift in reverse and opposite. 
Or need a clunch. 
Also the modern units are more complicate in the shift and oil system than it looks like. 

http://www.euronaut.org/content/gfx/equipment/Bowthrustermockeup01.jpg
http://www.euronaut.org/content/gfx/equipment/IMG_5913a.jpg

We scrapp both prototypes and purchase normal electric bowthruster and oil compensate them. 
Was much easier. 

vbr Carsten 

"Alan James" <alanlindsayjames at yahoo.com> schrieb: 
  Hi Joe,
  yes the bow thrusters are a better option.
  I thought that because of the mass production of outboards, that a lower unit may be reasonably cheap & adaptable. After further Googling I found they were reasonably expensive & there could be issues with the gear case oil getting contaminated.
  Alan


------------------------------------------------------------------------------
  From: Joe Perkel <josephperkel at yahoo.com>
  To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
  Sent: Saturday, October 26, 2013 8:30 AM
  Subject: Re: [PSUBS-MAILIST] Brushless Motor Drive


  Alan,

  Take a look a Lewmar thrusters, they have a 90 deg transfer case and housing that is purpose built, hydro-dynamically clean, and better adaptable that an OB lower unit, (that looks a bit cumbersome). I've not yet ruled out purchasing one in a boating flea market to get a closer look.

  The advantage here would be two fold, matching already known specs exactly including the use of the props, tip clearance,.. etc, and secondly, removing as you say the motor housing from the flow path.

  If I were to compensate, Id use the flex tubing method. But, I like pressure resistant housings for these "sport" depths. Like Popiel's Magic Oven, just "Set it and forget it!"

  Joe

  From: Alan James <alanlindsayjames at yahoo.com>
  To: psubs.org <personal_submersibles at psubs.org> 
  Sent: Friday, October 25, 2013 5:57 AM
  Subject: [PSUBS-MAILIST] Brushless Motor Drive


  Hi Psubbers
  I've been thinking about motor compensation options.
  Any thoughts about whether this idea may have any merits?.....
  Mount a brushless motor vertically on an outboard motor lower unit gear case
  & air compensate it.
  The length of the vertical drive shaft from the motor to the gear case gives
  plenty of margin of error for the air compensation system before any water
  could make its way to the motor.
  The gearing already exists for the higher speed of the brushless motor, & although
  there is an energy loss through the gearing there would be some savings in 
  that the motor is not directly in the path of the propellor thrust.
  A can would need to be made around the motor & sealed on to the lower unit.
  Regards Alan




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-- 

Carsten Standfuß
Dipl.Ing.Schiffbau @ Meerestechnik
Heinrich Reck Str.12A
18211 Admannshagen

0172 8464 420
WWW.Euronaut.org
Carsten at euronaut.org 
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