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Traction loss pivot point

Discussion in 'DIY Motion Simulator Building Q&A / FAQ' started by Shurup, Feb 27, 2017.

  1. Shurup

    Shurup New Member

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    Hello, I'm trying to add motion to my rigid simulator. I remember someone said there is no so much difference between using a pivot point for the TL on the front near the pedals or just under the U-joint. The sensations are almost the same. I don't know if it's correct that's why I end asking you about it. I was searching this comment on the forum but I was not able to find it. Somebody knows who said it? Help is appreciated.
  2. crammy

    crammy Active Member Gold Contributor

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    i would of thought it would be better at the front near the pedals. in a car the pivot would be the front wheels. if you put it near the u-joint you will just be twisting the seat.
  3. Shurup

    Shurup New Member

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    Not thinking about make it rotate from the u-joint, is more to make it move linear from left to right without pivot point.

    A platform sliding under my seat with my seat attached into it. The pedals and the wheel will remain static and my body feeling the TL.

    At least the lateral displacement should be the same as if it where rotating from the front.

    That's why I was asking about sensations.
  4. crammy

    crammy Active Member Gold Contributor

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    because you mentioned pivot i thought you were saying about putting a pivit point by the u-joint, which is why i was saying you would just be twisting the seat. it would work if you just moved the seat but would feel strange if your seat is sliding away from the pedals i believe.
  5. Shurup

    Shurup New Member

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    I believe I will feel my body sliding while my hands and feets are in the same place, something like using 2dof instead a full moving platform. You can feel forces in your body and it moves with the seat while everything is static.
  6. shannonb1

    shannonb1 Well-Known Member

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    Just did a complete redesign and build because of this. Take a pencil and grab it in the middle, imagine that where you sit is where you pinch the pencil. Now imagine what that does to your feet, its like spinning in an office chair......now move that pinch to the end amd inagine the mid point is your seat. The sensation is more true to life.
  7. abs

    abs Active Member Gold Contributor

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    pivot (lady suzan) near the pedals is beneficial as follow
    less stress on the motor as the arm lever is way bigger.
    the front wont move so much so it is better if you use stationnarry screens

    experiencing a pivot lady susan near the universal joint could be beneficial regarding simulating traction loss . The traction loss feel might be higher as shannonb1 said). if in process of doing it . it is worthwhile to experiment then (but at the expence of the torque and screen position)
  8. Shurup

    Shurup New Member

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    That's what I mean with sliding plate under my seat. Just find it on YouTube and I think it's doing good job with TL.

  9. racerandy

    racerandy New Member

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    If the pivot point is under the pedals, what is a good distance back to the motor?
  10. abs

    abs Active Member Gold Contributor

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    a good distance to alleviate stress on the motor is just the further the better . in my case the ladysuszan bearing is about 1 foot away from the pedals (towards the wall). the motor for traction loss is about 30 inches being ne from the universal joint (pivot point). The motor for traction loss is a SNC5 150 (10kg). 10 kg seemed to me a bit weak that is why I want a lot of leverage. If you use strong motor for traction loss there would be no problem to otimise the leverage (for instance strong snc6)
    according to me the further away the better from a stress point of view. The disadavantage is a lower "sensation" of traction loss as reported by Shannonb

    but to me the traction loss is very acceptable that way but there is always room to have better simulation inputs. That s what we 're all trying to achieve

    the problem I anticipate with a traction loss pivot too close to the universal joint is regarding stationary screens . But why not experiment by incrementation with a traction loss pivot a little closer with you universal joint
  11. shannonb1

    shannonb1 Well-Known Member

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    ok, so that video is from here, he is a member and his pivot point is not directly below the seat.
  12. Shurup

    Shurup New Member

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    Well is not really a pivot point is on a guide and displacing from R to L. What about that solution? Is really effective? Do you know what's his member name or thread log?
  13. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

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  14. shannonb1

    shannonb1 Well-Known Member

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    Side to side would be yaw and not traction loss.