Why do they keep on doing it?

Discussion in 'Outboards' started by tom kane, Dec 13, 2015.

  1. BMcF
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    BMcF Senior Member

    Is almost entirely negligible and has no effect on stability.
     
  2. gonzo
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    gonzo Senior Member

    They rotate very close to their center of mass, so it is irrelevant.
     
  3. Barry
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    Barry Senior Member

    Another significant aspect is that an outboard has the easy ability to be raised/tilted for trailering. A couple of rams and a pivot point and the prop and lower drive is above the bottom of the boat.

    And if you hit a log or the bottom the outboard can tilt up, with no damage, no significant damage, or a bent prop but often will get you home. The disadvantage of the Volvo IPS is that if you hit something hard enough, the whole unit is designed to breakaway but still keep the boat watertight.

    Most outboard driven boats are trailerable and this is an important feature
     
  4. tom kane
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    tom kane Senior Member

    There should be no problems turning the lower case on an outboard (or I/O) instead of swinging the whole outboard. You can do just about anything if you try. Does it matter if it does not appeal to some just so long as it works well.
    If reverse and forward and neutral box is under the power head and not in the lower gearbox that removes some problems.
     

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  5. BMcF
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    BMcF Senior Member

    What do you propose to actuate/control the lower unit rotation that can handle 1 or 2 hundred (or more) ft-lbs of torque? As compare to the 15-50 ft-lbs of torque required to steer a conventional large outboard?
     
  6. tom kane
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    tom kane Senior Member

    baeckmo, perhaps you were not taught to do some Research and think for yourself
    and allowed to come up with different and innovative ideas.
    Some Professional people do not understand the Laws of Physics or Engineering but need to be told what is right or wrong and follow traditional practices. It is called "Peer Review".
    Thank`s for your opinions there would be no debate with out differing opinions, just so long as you do not expect every one to accept your view as the only valid one.
     
  7. tom kane
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    tom kane Senior Member

    Like lot`s of people say the principle has been used before and is still being used to advantage and it just needs refining with modern materials and experience for your purpose.
    A few design modifications to cope with any perceived forces. You should be able to design something for yourself with your knowledge of mechanical forces and Engineering.
    Don`t fight the forces but make them work for you by design.
    What a challenge that would be.
     
  8. daiquiri
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    daiquiri Engineering and Design

    In conclusion: may the forces be with you.

    This thread is following the same usual pattern of 99% of threads started by Mr. Kane.
    I am running away. Good luck everyone.
     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    I'm sure it can be done, but to what advantage ?
     
  10. powerabout
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    powerabout Senior Member

    Chrysler / bayliner did it years ago just as Tom decribed.
    That made the outboard an inboard.
    Ps. No issue with outboards steering as all can have power assist now.
    Merc and brp have it integrated with the swivel bracket.
    Japs are a bit behind in that area.
    Best manual steering ever was omc stringer sterndrives where lower unit turned and top box was stationary.
     
  11. BMcF
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    BMcF Senior Member

    Just.....wow.

    Have a nice day.
     
  12. FAST FRED
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    FAST FRED Senior Member

    The hassle is every CEO of a large outboard mfg co, , or I-O leg maker is sitting on a factory created to make todays product.

    That it was yesterdays product is just fine as it allows older stuff to be kept up.

    AS the swiveling prop would have no efficiency advantage to the consumer , out dating every product now in production for no gain is not a rational option.

    Make the boat burn 15% less fuel or go 10% faster , perhaps competition might force a change. ,,,,till then forgetaboutit.
     
  13. tom kane
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    tom kane Senior Member

    If you had read the boating reports of the day lower gear case steering combined with a tractor propeller did give more efficiency and better speeds as they excelled in than competitions they entered in.

    As they say everything old is new again it just takes time for some people to wake up to good ideas.
     
  14. powerabout
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    powerabout Senior Member

    Volvo just released a sterndrive with tractor props like the IPS
     

  15. Barry
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    Barry Senior Member

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