Gimbal Cabin?

Discussion in 'Boat Design' started by stonedpirate, Sep 23, 2011.

  1. stonedpirate
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    stonedpirate Senior Member

    Thanks all.


    It was just a thought experiment.

    My design was an 8' sphere within a slightly larger spher with well oiled bearings.

    This is the main cabin of a small catamaran.

    Like this:

    [​IMG]

    Imagine a sphere within that cabin.

    The captains weight on the bottom would be the ballast of the sphere and the boat itself would rotate around it.

    Even capsized, i would still be sitting upright insted of being flung to the ceiling.

    Like i said, just messing around with the idea.

    Didnt realise it would have its own momentum. I wonder if there is a point where ballast is heavy enough to keep the inner sphere level?
     
  2. Submarine Tom

    Submarine Tom Previous Member

    It is certainly possible but hugely challenging.

    Dampening would be the key.

    -Tom
     
  3. Squidly-Diddly
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    Squidly-Diddly Senior Member

    ten foot long or ten foot wide?

    I have to ask.
     
  4. TeddyDiver
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    TeddyDiver Gollywobbler

    Get a hammock ;)
     
  5. upchurchmr
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    upchurchmr Senior Member

    I think you should look at the modern washing machines. Instead of spinning they slosh back and forth in a powered motion. If you use some electronics to sense vertical, you could design a control system which drove the "sloshing" motor to keep the cabin vertical. Might be pretty expensive for the redesign, and I don't know that you could get the reaction time fast enough to not be out of sync and act like the ballasted examples above.

    Actually, I think if you dislike the motion so much you should get a bigger boat or a bicycle.:rolleyes:

     
  6. upchurchmr
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    upchurchmr Senior Member

    Sorry, I guess I should not have been so negative, I suppose this will get deleted like the last time I got sarcastic. Thought police are everywhere.
     
  7. Wavewacker
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    Wavewacker Senior Member

    just a few days ago there was the same proposal....I think you'd be better off thinking bigger first of all because it will take some hardware and breaking mechanisims to control and slow the rotation, which mean more weight.

    The gimbal contraption will have an x and y axis, a ring around the cabin on one and that ring on another axis 90 degrees. Each axel will need a locking brake to keep it somewhat in the position desired and released as needed.

    The axels could also run in to a something like a rotary engine with fluid and ports allowing the fluid the be pushed out of one port and in to a reserve that would be replaced in the rotor, slowing the rotation of the axel or stopping it.

    It could be electrically controlled to a mechanical method. Perhaps magnetically. Investigate targeting systems on a tank.

    Something strong enough to mount a cabin to will need to be pretty stout to take the abuse, so I would think it would need to be out of steel (or some very expensive materials keeping weight down, like cabon fiber) but on the cheap, steel. The mechanisim will also need to be heavy duty as well, more steel. All this could weigh between 500 to 1,000+ pounds.

    So, you just turned Miss Cindy into a submarine.

    Instead, why don't you figure out how to allow a catamaran to be connected fore and aft so that the hulls can rotate if capsized and allow the frame members to remain upside down.

    Anyway, what ever you power it with would need to be on a wire or remotely. Are you going to have your motor mounts rotate as well?

    Maybe the easiest way is to build a cat with a high clearance bridge deck and hang a hammick (sp?) between the hulls! Use some bungee cords off the sides to keep yourself from banging in to the hulls....:rolleyes:
     
  8. stonedpirate
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    stonedpirate Senior Member

    I'm not sure what you mean by that but it just gave me the ultimate brainwave.

    Imagine a cat with two symetrical hulls that work the same when capsized. So regardless of which way is up, it is the same boat.

    Obviously you cant use a mast and sail as it will be under water.

    But use a kite on a swivel. So the cat can roll completely and the cabin is always level.

    That way you can have the speed of cats without the (cats are too easy to capsize and too hard to upright comments).

    [​IMG]
     
  9. upchurchmr
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    upchurchmr Senior Member

    Stonedpirate

    Have you seen this thread?
    http://www.boatdesign.net/forums/multihulls/gyroscopic-multi-hull-design-39457.html

    Similar ideas, just as bad. Have you ever sailed a cat?
    Cats are not EASY to roll. Just put up a trivial amount of sail and go as slow as a monohull. The other trick is to make them very wide, also. There have been some production boats that used a weighted centerboard or daggerboard. They didn't last long in the market.
     
  10. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Jeremy, your mistake with the bed was keep it at low level.

    I suspended a bed up high, loft style, on about 40" wires.

    Worked fine, and I had a nice sprawling desk underneath.

    The "bed" was just 1 1/8" plywood 4' x 8' sheet with 2x6 on edge down the middle underneath.

    The wires werent straight down but a traziod one 16" OC joist wider, so 8" on each end (and on sides) and it would very much 'find level' and only move a little.
     
  11. Jeremy Harris
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    Jeremy Harris Senior Member

    You're spot on there! With the 6ft plus long wires I used the motion of the bed was crazy, it would sort of dart around in a very uneven swaying movement. After a drink or two it was hard to tell whether your head was moving internally or the bed was moving, definitely not one of my better ideas!
     
  12. kach22i
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    kach22i Architect

    That is one of the most interesting things I've seen in a while.:)
     
  13. Pharllap
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    Pharllap New Member

    Very old thread, but as a truck/tractor/lorry driver I'm thinking truck drivers Suspension seat principle at each end or side (extremely small extremely simple yet extremely effective) and considering it's for a Cat youd assume most of the motion be in the for and aft axis so only 2 sides or ends needed
    Happy sailing from Perth
     
  14. JamesG123
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    JamesG123 Senior Member

    The problem remains, a truck seat has a fairly narrow range of dampning it need be designed for, whatever bumps the suspension doesn't soak up. Where as a boat can rotate at all sorts of amplitudes from gentle rocking to being slammed by rollers. No passive system can cope with that.

    Why I thought to also post on a dusty old thread, is that since '11, micro controller computers, gyros, and hi-torque stepper motor/servos have gotten much cheaper and available. Whats more, a veritable cottage industry has sprung up to supply people who want to tinker with Arduno and Raspberry Pi computers to automate everything from the practical to the ridiculous. Its gotten to the point you don't need to know much about electronics or programming to build something. It would now be pretty easy to build a gyro-stabilized cabin like the OP was asking about.
     

  15. Squidly-Diddly
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    Squidly-Diddly Senior Member

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