ffb braking

Discussion in 'Car Modding' started by sangreone, Jan 13, 2021.

  1. sangreone

    sangreone Registered

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  2. mantasisg

    mantasisg Registered

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    Totally missed. Will check out soon.
     
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  3. mantasisg

    mantasisg Registered

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    Hey, finally got to launch rF2 again.

    Sorry I haven't done proper examination so far for that bad oscilation problem and overall bad kart feel. I think it could be related to some geometry/inertia problem, I'll look at that other day.

    One thing that I could tell right away is that the FFB is massively clipping, I noticed there is no nominalFFB value in hdv, I have added quite a massive one and quite a bit of handling feel got revealed, clipping went away or decreased.

    Didn't examine anything, but at first glance physics files looks serious, I suppose you took some existing kart as base physics.
     
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  4. lagg

    lagg Registered

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    Some real drivers of the category are helping @sangreone with this car.
    Then, the data are real.
     
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  5. sangreone

    sangreone Registered

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    Thanks friend! the basic physics are the ISI karts. The rest of the physics has been implementation of real data and feedback from the real drivers of the European and British championships. It is very possible that you are right and the error is inertia, which is probably the most blindly modified value. You will find it in UPGRADES. ;)
     
  6. mantasisg

    mantasisg Registered

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    I gave some time for this again, seems like troubles come from "steeringshaft..." and "steeringinnertable" parameters. Delete them, or readjust if you know how. I just delete them.

    Another thing to look at would be readjusting front geometry, because your kart has narrower tracks it appears to have crossing left versus right inner pickup points. Perhaps it could be something that is wrong. I also tried to drag front spindles more towards wheels, readjusted wheel joints x axis locations, drag whole wishbones + steering links more towards wheels, it seemed to have good effect. I also used resolved subbodies innertias. But at the end I just switched to ISI_Kart geometry for random test, it proved that you may like to do little changes for geometry as oscilations came back, but steering in general was fixed by deleting those hdv values which I mentioned in beginning of this post..

    P.S. I took a little glance at aero downforce values, IMO they are rather big.
     
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  7. sangreone

    sangreone Registered

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    Thanks friend.

    The downforce is designed to match that of a real superkart, which has nothing to do with a tourer or a formula. Basically the rear wing has to go to 0, at most 1 to compensate for the added front load, but never more degrees unless the track is wet. The real importance is in the difference in height between the front and rear of the "nose".

    It is possible that the error is in "steeringshaft ..." and "steeringinnertable" as you comment at the beginning. The geometry should not be a problem because we adjust it with the help of real superkart drivers and mechanics, and adhering to real parameters of manufacturers and sports regulations.
     
  8. Jokeri

    Jokeri Registered

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    Can you try and make scrub radius 0?
     
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  9. sangreone

    sangreone Registered

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    I don't know how I should get this?
     
  10. Lazza

    Lazza Registered

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    I've only read very little on kart geometry, but I suspect 0 scrub would be quite a departure from most normal setups.
     
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  11. djbob

    djbob Registered

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    I'm having this FFB issue when the car is stationary also (when brakes are pressed). The vibration comes through the steering FFB and the motion actuators which is not ideal when the car is supposed to be stationary!
    Trying to change various parameters currently to see if I can find where the problem is coming from.
     
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  12. mantasisg

    mantasisg Registered

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    I already wrote where it is from, but if you could come up with more findings or more accuracy it would be helpful for sangrone, I guess.

    P.S. on the aero offtopic, the downforce hdv values are surely high for a car like this, even if it would be size of a normal passenger car. But I have not checked actual change of wheel loads due to aero.
     
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  13. djbob

    djbob Registered

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    That didn't fix my issue so still looking for the problem currently.
     
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  14. mantasisg

    mantasisg Registered

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    Geometry changes + those particular HDV steering lines removed fixed that issue for me.

    Anyway, I tried to help, I don't think I should be fighting to prove myself. Good luck.
     
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  15. sangreone

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    Thanks mantasisg. I appreciate your help to the fullest. The debate is good.

    As for the downforce, I do not plan to change at the moment. Thanks. It has no effect on the ffb issue.
     
  16. Lazza

    Lazza Registered

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    I tried it and had the same (press the brakes hard, turn the steering one way, then the other... vibration), and removing the SteeringInnerTable lines (all 5 of them) seemed to stop it happening. Can you confirm that didn't work for you?

    @sangreone have you used the physics spreadsheet to create these cars? (I don't think I have access to the base cars you used, so I can't compare...)
     
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  17. djbob

    djbob Registered

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    Yes I tried taking out all 5 x "steering..." lines in the HDV but it didn't fix the problem in my case. Will try some more things tomorrow and let you know if I find it.
     
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  18. sangreone

    sangreone Registered

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    Thanks for the help Lazza and djbob.

    I have not used spreadsheet because the mod is basically the old 90% ISI karts. From that mod we have created a new engine, gearbox, tyre grip and downforce until the real riders have been satisfied. All manually.

    In the ISI mod there was no ffb problem, because the brakes were not as powerful as now. As a result of increasing the power of the brakes is when the problem arose.
     
    Last edited: Apr 27, 2021
  19. Lazza

    Lazza Registered

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    Ok, makes sense (most of that stuff isn't so exacting that a small error here and there will create issues). Does that mean the Steering entries in the [CONTROLS] section are original, or are they yours (or edited)?
     
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  20. Jokeri

    Jokeri Registered

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    Move the suspension outer points closer to wheel.
    My experience is that large scrub radius, in my case over 100mm caused vibrations while braking.
    Not ideal to change it as it changes the suspension geometry and probably doesnt match your kart..
     
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