Realfeel + microbumps + G27 :(

Discussion in 'Hardware Building/Buying/Usage Advice' started by doggod, Jan 2, 2011.

  1. doggod

    doggod Registered

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    Any one else running into an issue with running realfeel and a g27 on a track with micro-bumps (VLM_LeMans)
    the micro bumps seem to be creating a massive racket(feels like 2 straight toothed cogs that are 2 far apart from each other so that the teeth move a certain distance before hitting the tooth on the other cog and then reversed ) on my g27 on the secondary motor.
    Testing using the World Sportscar 1970 which is built for realfeel and comes with particular settings for the cars, using the Porsche 917K
    When doing a testing session and i have to drive out to the track from behind the pits it starts straight away. To me it seems that the micro-bumps are being interpreted incorrectly and sent to the effects motor rather that the main ffb motor of the wheel, or that the wheel is interpreting the effect incorrectly , is it something in the track files telling the realfeel what to do , or realfeel not realizing that there are 2 motors or something else.
    Ive tried everything from 300 to 900 degrees and varied the ffb strength from 50 to 100 still with the same issues.
    If any have advice id much appreciate it, i have secondary effects on for braking in gtr2(these effects go to second motor and feel like a rumble effect, here its like the 2 cogs from above are meshed together correctly so that there is no distance between the teeth so no racket just rumble) and the feeling is sublime compared to realfeel, i assume this is the feeling that im suppose to get from these micro bumps in rfactor.
    If any want the settings i use in gtr2 to compare the feeling ill gladly post them.

    Please, please for rfactor 2, test and test the ffb so it can be smooth for all wheels

    I mean no disrespect to either the track makers, micro-bumps or realfeel devs by this post

    PPS , for anyone not understanding my cogs description try this.
    Hold your hands out and spread your fingers as wide as possible, now put one set of fingers between the other and start to move your hands, see the way your fingers are banging together(racket) ,now close your finger so they are just touching and move your hands(rumble)
     
  2. Noel Hibbard

    Noel Hibbard Registered

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    My guess is you have MaxForceAtSteeringRack set too low. Try setting this higher and see how it feels. Don't trust the suggested values in the readme files. They often set MaxForceAtSteeringRack too low trying to make the wheel more heavy but the problem is very small bumps translate to big forces. If you set this value to low you can't differentiate small bumps from large bumps. Think of it like audio clipping due to too much gain on a digital EQ.
     
  3. doggod

    doggod Registered

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    No the overall forcefeedback is very good using 5500 from the mod and realfeel and 2500 is the smallest value they suggest,default is 1500,
    the issue is with the secondary effects motor, but clipping is a good description.
    If you want to feel the effects in extreme, that im talking about , grab any of the codemasters demos , Dirt Dirt2 eg
    set the environmental effects in game to 100 with a 900 degree rotation, nothing to do with ffb generated in game from (physics calculations)
    only extra effects to differentiate driving on tarmac to gravel etc.
    the secondary motor in g25 g27 seems to be for extra effects (canned)
    Its why 90% of settings you see for the g25 g27 for gtr2,rfactor,race series suggest leaving the effects to low in wheel setup
    as this doesn't include any of the canned effects,
    set it to medium and you get rumble when braking and throttle, high gives more canned effects and full includes all the canned effects.

    The issue to me is that realfeel doesn't seem differentiate between the 2 forcefeed back motors so they sent the same force value to the secondary(canned) motor as the main motor
    reducing the DefaultSteeringDamper to aroung 400 instead of 11500 helps a lot with but dosent remove it completely.
    Fanatec got around this problem as they put the extra (canned)effects motors as vibration motors with the wheel rim
    trustmaster seem to have done the same with the new wheel they are bringing out for the ps3.
     
  4. Lazza

    Lazza Registered

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    This is a G27 'feature'. If you plug your wheel in, turn it to the right so it's pushing against you, and rock it quickly back and forth around that point, you'll hear that 'knocking'. It's the shaft of the right-side motor moving 'up and down' due to the helical gearing. (the G25 does not do this)

    rFactor has, by default, a maximum change per frame... I think by default it's 15 or so, so (I think) 15% of full FFB per frame. This eliminates the knocking noise.

    Of course, RealFeel (and other FFB plugins) may not implement such a feature. From memory I think RealFeel can smooth the output to some extent, so maybe try that. Of course this may also reduce the FFB fidelity, but it's really one or the other in this situation.

    This is the one thing I don't like about the G27.

    By the way, there isn't a primary or secondary motor in the G27. One pushes to the right, and one pushes to the left. You won't hear the knocking noise when the wheel is turned left, because the left-side motor doesn't do it.
     
  5. doggod

    doggod Registered

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    Thanks for the info Lazza

    After some searching i see where the issue is coming from, and think i may have a possible fix
    http://www.jlvrh.de/G27_UK.htm shows how the g27 is disassembled
    pic 13 and 14
    what im thinking is that is a cylindrical piece of foam rubber was placed within the spring(spring seems to be considered too weak from what im reading) and if needed a soft rubber washer put in the back of the white plastic housing that takes the motor shaft
    It depends on whether its the motor shaft hitting of the white housing or the white housing thats hitting of the casing thats making the most noise. Im assuming its the second one,
    Ill have to do a bit of research on the rubber foam that i can get.
    If it was possible to even deaden the noise from spiked inputs id be very happy.

    I played around some more with the settings in realfeel, the smoothing goes all the way up to 9 which eliminates most of the racket but you do loose fidelity.
     
  6. Lazza

    Lazza Registered

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    Hopefully you can sort something out along those lines. I'd suggest taking it apart first so you can see exactly what's happening - I'm pretty sure the spring is used when the motor is activated, because of the gearing the shaft is pushed 'up' (towards the user), and the noise occurs when it comes back down (the contact you're hearing is within the motor itself) - so a rapid force -> idle change produces it. I guess you can either try and put something at the bottom end to stop the shaft more quietly, or add more to the top so it doesn't actually travel anywhere.

    The risk would appear to be what stresses you might place on components in doing so. It seems unlikely Logitech didn't notice this noise (though I guess you can't rule anything out), so perhaps not implementing a 'quick' fix was from an engineering/reliability viewpoint.

    Best of luck with it, anyway.
     
  7. Noel Hibbard

    Noel Hibbard Registered

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    My understanding is the second motor isn't for effects. The two are identical push away from each other. Logitec says it is for "anti-backlash". Older Logi wheels had a dead-zone when you changed the direction from left to right quickly. The G25/27 still has a little lag but nothing like the old wheels. They always suggest setting the effects level to Low for RealFeel because they are trying to minimize the canned stuff. RealFeel will shake on rumble strips assuming the track has 3D curbs. I completely disable canned stuff but setting this:
    Code:
    FFB steer force output max="0.00000"
     
  8. Marek Lesniak

    Marek Lesniak Car Team Staff Member

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    Anti backlash is only in G25. You have main toothgear divided in 2 parts, connected with springs., with an offset between the parts by a 1 tooth (springs are strained by that).
    That creates tension, which eliminates (to some extend) the freeplay between the teeth (the second part of the main toothgear, beeing on strained strings, wants to pull pack, thus eliminating backlash).
    Becaus G27 has helical gears, providing such system wasn't possible. That's the reason for that rattle. Too bad, because putting a set of helical gears was a relatively big improvement (providing less "mechanical" feeling to FF, compared to G25).
     
  9. Noel Hibbard

    Noel Hibbard Registered

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    I think we are referring to two different things when we say backlash. I am referring to the older wheels like the MOMO where your trying to turn to the left so the motor turns to the right so the wheel feels stiff. Then you decide you now what to turn to the right and as you make that transition from left to right the motor actually turns to the right for you for a split second until the electronics catch up. I think when you are referring to backlash you are referring to the very tiny bit of slack between the teeth. On the newer wheels they have two identical motors. They apply forces in opposite directions only one is given a little more power then the other. So when you make rapid changes from left to right there is less lag or at least it is less noticeable. That is my understanding anyways. Could be way off. :)
     
  10. yokelhama

    yokelhama Registered

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    Not sure if this'll help or not but with my G27 I need to open the Windows Game Controllers menu every time before I start rfactor or I'll have violent ffb. On both the Global device settings page and the Test page I need to turn the wheel from lock to lock and press the acclerator, brake and the gear paddles. Then when I start rfactor the ffb is now correct. Also I use a modified controller.ini from the NoGrip website. I used to have a Logitech DFP and I'm wondering if I still have a few phantom drivers creeping in and confusing everything.
     
  11. Marek Lesniak

    Marek Lesniak Car Team Staff Member

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    Yes Noel. And you are talking about oscillations. You don't have that in G25 and G27 (and probably DFP too but I don't remember, had that wheel a few years ago) because "smart" Logitech decided to weaken FF forces near the center at a hardware level. The oscillations have gone, but you have worse feeling about what's happening on the track when going straight. To compensate that, I had to change force exponential in rF FF settings, from 1.0 (which is a perfect linear force response throughout the wheel rotation range) to values like 0.6 (you get more force near the center, which compensates its lack that you would have otherwise).
    Why I said "smart" Logitech? :) Well, because it should be up to the user to decide, does he want good FF response at a cost of having oscillations or not, through a switchable option in the drivers. Shouldn't be hard to implement that, right? ;-)

    You can compensate that too even with RealFeel, but you have to have FF profile set to at least "High" (or medium. Kill me, I don't remember right now) in Controller.ini. With "Low" (which is recommended by rFFB plugin maker), that parameter won't work (is not used).
     
    Last edited by a moderator: Jan 12, 2011
  12. Noel Hibbard

    Noel Hibbard Registered

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    FFB level in rFactor just changes the number of canned elements that get sent to the wheel. Even at Low some canned crap slips in. The best way to totally disable canned crap is:
    FFB steer force output max="0.00000"

    If you set that and then turn off RealFeel you will have absolutely no forces at all sent to the wheel. Not even a centering spring. This is the best way to get pure RealFeel with no BS.
     
  13. killdrums

    killdrums Registered

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    Just wondering what your profiler setting are for the g27.I use real feel...put FFB steer force output max at0.0000 thanks Noel!
     
  14. killdrums

    killdrums Registered

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    No worries...got rid of real feel.....did some resetting...all good now:)
     
  15. Noel Hibbard

    Noel Hibbard Registered

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    Crap... sorry I missed this post. Here are my settings:
    2011-01-18_160032.png
     
  16. Stroker

    Stroker Registered

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    I know exactly what you mean. That is one of my favorite rFactor tracks. I just got a G27 and it does what you describe to an extent, but my old momo that it replaced was awful. It would shake 4-5 times as much as the G27 does. I'll experiment with some things suggested here and see how it goes. Thanks everyone for the good information in this thread.
     
  17. MystaMagoo

    MystaMagoo Registered

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    Yes,smart logitech,what were they thinking?

    I hate the horrible low FFB center on my G27.
    You especially 'feel' it in flip flop and fast chicanes.
    Wish I could get rid of it :(

    Contemplating getting an Fanatec GT3RS?????
     

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