1. Do not share user accounts! Any account that is shared by another person will be blocked and closed. This means: we will close not only the account that is shared, but also the main account of the user who uses another person's account. We have the ability to detect account sharing, so please do not try to cheat the system. This action will take place on 04/18/2023. Read all forum rules.
    Dismiss Notice
  2. For downloading SimTools plugins you need a Download Package. Get it with virtual coins that you receive for forum activity or Buy Download Package - We have a zero Spam tolerance so read our forum rules first.

    Buy Now a Download Plan!
  3. Do not try to cheat our system and do not post an unnecessary amount of useless posts only to earn credits here. We have a zero spam tolerance policy and this will cause a ban of your user account. Otherwise we wish you a pleasant stay here! Read the forum rules
  4. We have a few rules which you need to read and accept before posting anything here! Following these rules will keep the forum clean and your stay pleasant. Do not follow these rules can lead to permanent exclusion from this website: Read the forum rules.
    Are you a company? Read our company rules
Shared accounts will be removed Plugin Downloads Zero spam policy Forum Rules

Roll axis in a Rally or GT car

Discussion in 'DIY Motion Simulator Building Q&A / FAQ' started by Deus Tempestas, Apr 15, 2022.

  1. Deus Tempestas

    Deus Tempestas New Member

    Joined:
    Sep 17, 2010
    Messages:
    6
    Balance:
    16Coins
    Ratings:
    +1 / 0 / -0
    I've have an idea to fix something that probably isn't even a problem. :think
    The roll axis, for a flight sim or an F1 car you sit straddling the roll axis. Positioning the roll pivot under the middle of your motion sim seat makes sense.
    But what about a GT or Rally car? In a left hand drive car the roll axis is to the right of your seat, under the shift and handbrake.
    Can the software move the axis to the side or do I need to build wide rig to put the pivot to my right?

    Some very rough calculations
    Assuming a 2m wide wheelbase on the car, left seat edge 20cm from left wheels and right seat edge 20cm from center of car.
    Tilt car 10º right and the left side of the seat rises 35cm right side by 21cm,
    Tilt car 10º left and the left side only rises by 2cm and the right by 7cm
    Seems like your body would notice that large of a difference.

    I've only ever ridden in an F1 style simulator before.
    Does my thinking here make any sense? Am I seeing an issue that doesn't exist?

    Thanks in advance for any comments. Two Axis roll.png
    Deus Tempestas, Apr 15, 2022
    #1
  2. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
    Jul 13, 2014
    Messages:
    20,555
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    145,148Coins
    Ratings:
    +10,780 / 52 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
    Set sway to lean away from a corner and roll opposite.

    Perceptually, particularly in something as fast as a GT car, the perceived roll movement, say running up a curb will be from the side it occurs.

    Keep in mind that the purpose of a motion simulator is to exploit physiological and physiological processing weaknesses, to provide adequate cues to have the brain accept something as real when you know it is not, rather than trying to recreate all real world forces, which is not practical for a motion rig, particularly a DIY rig.
    • Agree Agree x 1
    noorbeast, Apr 15, 2022
    #2
  3. Deus Tempestas

    Deus Tempestas New Member

    Joined:
    Sep 17, 2010
    Messages:
    6
    Balance:
    16Coins
    Ratings:
    +1 / 0 / -0
    That all makes sense.
    Just over thinking it :grin probably won't make a big enough difference to notice.
    Don't have room to start building my rig until after I move, so just brainstorming.
    I'll dig into the plugin manual a bit deeper and see if there is a way to maybe scale the roll input to move the pivot in software.
    Deus Tempestas, Apr 15, 2022
    #3
  4. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
    Jul 13, 2014
    Messages:
    20,555
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    145,148Coins
    Ratings:
    +10,780 / 52 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
    Before messing with plugins I would suggest digging deeper into understanding motion simulation as exploitation of processing weaknesses, and then considering the applicability of that to the limitation and possibilities of potential rig designs: https://en.wikipedia.org/wiki/Motion_simulator
    noorbeast, Apr 15, 2022
    #4
  5. Deus Tempestas

    Deus Tempestas New Member

    Joined:
    Sep 17, 2010
    Messages:
    6
    Balance:
    16Coins
    Ratings:
    +1 / 0 / -0
    Thanks for the link, down the rabbit hole I go!
    • Like Like x 1
    Deus Tempestas, Apr 15, 2022
    #5
  6. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
    Jul 13, 2014
    Messages:
    20,555
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    145,148Coins
    Ratings:
    +10,780 / 52 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
    Its a deep but fascinating journey down that rabbit hole, which may even bring into question what type of motion rig you want to build.
    noorbeast, Apr 15, 2022
    #6
  7. Deus Tempestas

    Deus Tempestas New Member

    Joined:
    Sep 17, 2010
    Messages:
    6
    Balance:
    16Coins
    Ratings:
    +1 / 0 / -0
    I want to try something a bit different, I'm thinking I'll start with a 2DOF with the pivot point behind and to the right of the seat where the center of a road car is.
    Then add a 3rd for yaw/traction loss later.
    Deus Tempestas, Apr 17, 2022
    #7
  8. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
    Jul 13, 2014
    Messages:
    20,555
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    145,148Coins
    Ratings:
    +10,780 / 52 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
    By all means do experiment, it would be fascinating to consider how things such asymmetric power/motor/motion profile demands are dealt with to ensure proper motion dynamics.
    noorbeast, Apr 17, 2022
    #8