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Center of gravity discussion on 2 DOF platforms

Discussion in 'DIY Motion Simulator Building Q&A / FAQ' started by tomkil192, Aug 14, 2015.

  1. Nick Moxley

    Nick Moxley Well-Known Member

    Joined:
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    Owner/Operator- Moxleys Rantals
    Location:
    Winnipeg Manitoba Canada
    Balance:
    17,054Coins
    Ratings:
    +2,504 / 30 / -2
    My Motion Simulator:
    2DOF, 3DOF, DC motor, JRK
    little more backround on Full frame VS seat mover in case your curious.

    http://www.cxcsimulations.com/products/motion-pro/how-it-feels/

    And special attention to watch the RBR video for reference since that is your main goal, PS it will play automatically actually. Enjoy.

    http://www.frex.com/gp/motion/motionpage1.html
    • Informative Informative x 1
  2. Dusko Dogandzic

    Dusko Dogandzic New Member

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    thanks for your input i looked and read some more about it and decided to test it out by calculating weights and forces involved in movement because i think with right profile u can tweak it to feel any way u like i will start a thread as soon as i start making something so far for electronics i have MM and ARDUINO

    does anyone have experience with 2 X 8800 gtx gpu`s for 3 monitor setup?
  3. Bruceaust

    Bruceaust Member

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    Occupation:
    CNC Routing
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    My Motion Simulator:
    2DOF
    Hi all,
    I have not posted for a while. But I have the urge to start a new project with some new ideas
    for my diy race Sims.
    History:
    I have built 2 Sims , both joy rider type designs (ie: both have 20 deg + rotation on both axies.
    The center of rotation on both these Sims was as close to the center of gravity as possible.
    Sim 1 was a fairly upright driving position (v8supercar) and sim 2 was a F1 reclined driving position.
    Bother have been very successful. But I have always thought there was something not quite right
    with motion.
    For the last year or so I think I have to much time thinking about this problem!!
    I have come to the conclusion that the centre of rotation should be as close to your eye position
    as possible.
    Think about the physics and the forces acting on your body as the sim rotates. I believe most Sims (including mine) are working back to front WHEN THE SIM IS MOVING to a new position.
    Having the rotation point at the eyeball point makes all the physics work in the correct sense as the sim rotates to a new position. It will push and pull your body with a force that has a "similar" sense of direction to the real life situation.

    To be continued. ........... next post
    • Informative Informative x 1
  4. Bruceaust

    Bruceaust Member

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    My Motion Simulator:
    2DOF
    I offer these ideas as a discussion on this important aspect of our hobby.

    All the sims that have been made by guys of this and other forums have one main aim: to try and fool the brain into thinking we are actually driving a “real” racimg car. So he closer we can get our sims to deliver forces that simulate to forces in a real car the more realistic our simulation experiences should be. This is why my next sim will have this in mind.

    By having the center of rotation at the “eye ball”, when braking the force applied to your body pushes on your chest as the sim rotaes in a forward direction. And vice versa, when accelerating the force applied when rotating the sim up and backwards needs to push on your back – just as it is in the real car. This can only be achieved when the center of rotation is at the top of your body ie: at or above your head. The same argument applies to lateral moves from side to side.

    Thoughts anybody?
  5. bsft

    bsft

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    Got a sketch of what you mean?
  6. Bruceaust

    Bruceaust Member

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    My Motion Simulator:
    2DOF
    This is the idea:
    sim sketch.jpg
    • Informative Informative x 1
  7. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
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    Innovative tech specialist for NGOs
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    St Helens, Tasmania, Australia
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    145,034Coins
    Ratings:
    +10,776 / 52 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
  8. Bruceaust

    Bruceaust Member

    Joined:
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    Occupation:
    CNC Routing
    Location:
    Launceston, Tasmania, Australia
    Balance:
    63Coins
    Ratings:
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    My Motion Simulator:
    2DOF
    Thanks Dave and noorbeast I will check out the other threads.
    As always somebody has already thought of it first ,ha ha
    • Like Like x 1