Sim Racing servo ffb systems : OSW & Bodnar

Discussion in 'General Discussion' started by Adrianstealth, Jun 1, 2015.

  1. Adrianstealth

    Adrianstealth Registered

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    delivery from Ollie showed up earlier, my pal will be happy, a few other friends who are upgrading to servo systems will be chomping at the bit too, heavy boxes!

    [​IMG]


    incredible , full servo system for a cost of £920 ( as transferred to Ollie , this was of course England delivery ) even if components at the cheaper end of the scale still great value,
    -I'm looking forward to comparing to the bodnar V2 (53)
     
  2. Markj

    Markj Registered

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    I'll admit I'm struggling with some of the technical content of this thread, but just wondering; Why did Simexperience choose a stepper motor for their wheel, surely there can't be much cost difference over the small mige?

    Also does anyone know if there is any company planning a commercial product that uses a non stepper servo motor that would be more cost effective than the Bodnar?

    Just intrigued as I have been tempted by OSW and Accuforce but held off so far after getting no response from Ollie to an enquiry a month or so ago.
     
  3. Marek Lesniak

    Marek Lesniak Car Team Staff Member

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    It has been discussed already on this forum. The difference is huge as we are talking about a $70 stepper motor vs $230 MiGe (the cheapest of that kind I believe).
     
  4. Adrianstealth

    Adrianstealth Registered

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    Ollie is getting stacks of emails I think, I'd just perhaps order the parts if no response after a while ( if you want to go servo system)


    I'll state again & again that nothing is close to these servo systems
    A T500 or an AF is not in the same league, ignore all the dribble on these forums it's fairly easy to see the people writing in most cases are also completely confused ( although the pretty graphs are nice) ( I don't mean any offence to anyone this is just the way I see things)
    do what I now do & don't bother reading it lol or add people with mega long posts to ignore list, see if you can find some one local to try hands on for yourself etc that is the very best way,
    technicals are also very nice but I'm happy that I've forgotten more than I now know but don't care .....as a complete servo system is light years ahead of anything else for ffb

    ( I have about 7 ffb wheels including a frex/7000 & used an AF out of Curiosity for a couple of weeks to test & it's a mighty fine wheel & I'd place it the best in the upper mid range but dosnt touch the servos systems which I put in the high end )

    ps will try this OSW this week
     
    Last edited by a moderator: Dec 7, 2015
  5. Jokeri

    Jokeri Registered

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    Go for OSW. You cannot go wrong with it, small mige is more than enough.

    I have OSW with small mige and in my mind, 1500e kollmorgen servo its not worth it. If you have money to spend go with kollmorgen motor, otherwise get small mige.
     
  6. Adrianstealth

    Adrianstealth Registered

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    if I were in the market right now for a new ffb wheel & not currently getting a response from Ollie ( & a bodnar out of my price range) this is what I'd do:

    A) contact Leo bodnar to see if they have any V1 systems available ( long shot )
    B) consider ordering parts to build an OSW myself eg no kit -maybe getting a few people together and do a small batch order ? this may reduce costs slightly,
    I think there is currently a few awaiting an Ollie response, here is the current list with current prices :

    [​IMG]

    UK VAT ( tax) is +20% paid to customs prior or on delivery ....THESE ABOVE COSTs include this, please make adjustment for your own countries tax if applicable

    an enclosure ( case ) would be needed, a lot of people use a mini ATX PC case,
    I think maybe a few cables & sockets need to be factored in too but not many as some of the components simply plug together
    ( Im assuming these don't come with the various components ? )

    Ollie seems totally sound & helpful, but I think there has been a high demand for his kits and he must have a mountain of emails to get through etc, he was kind enough to supply this list (above) to me as an alternative to him supplying , but my pal was happy to wait as he wanted it for Xmas holidays, it's worked out nicely for him.

    ps if your capable of building your own PC then this should be zero problem for you

    I hope this is info is useful & helpful
     
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  7. Prodigy

    Prodigy Registered

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    Adrian, the part list above, those are parts available to buy from Ollie? Or just a list what you can buy from other suppliers?
     
  8. Adrianstealth

    Adrianstealth Registered

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    hiya prodigy

    these are the parts in his kit, so yes available from Ollie, but Ollie seems back logged at the moment,
    so this list is to help anyone wanting to simply order independently -think of it as ordering parts to build a PC
    this is the parts list to an OSW (as the kit that Ollie supplies)
    so the parts are suitable tried and tested / working together servo system with budget in mind

    the firmware / ffb UI software is a free download
     
  9. Joe

    Joe Registered

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    It will be next year. I am not hurry. I either DIY myself or OSW, or buy from others:

    http://www.ECsimhardware.com
    http://www.RealisticSim.com
    http://www.simsteering.com

    seem many options. Definitely get rid off the stepper motor. I have long doubts on the stepper motor on torque response (slope of the curve shown in your charts). The charts you posted confirmed that. I seemed happy with AF wheel, but now your chart made my life harder (LOL). BTW, I care less about the encoder rate, it overkill and meaningless on this application. this is a cheap marketing trick....
     
  10. Adrianstealth

    Adrianstealth Registered

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    uboxed , I can confirm that everything is shiny

    [​IMG]

    I'll try to find a graph to post -maybe a blue one with a line that starts low and finishes high,
    and trichomoniasis figures just to compare :D
     
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  11. DrR1pper

    DrR1pper Registered

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    Yeah. The initial lag and initial rate of acceleration are actually basically identical for both AF and OSW. The issue seems to present when the AF velocity (trace) surpasses 100 rpm, after which it begins to struggle to maintain the same rate of climb (i.e. acceleration) up to its terminal velocity which suggests it's struggling to maintain the same torque output.
     
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  12. Euskotracks

    Euskotracks Registered

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    Very interesting question.
    I am not sure how this affects to a servo system working in torque mode.

    Led already explained that in this mode torque control is accomplished by controlling current in closed loop. I am not sure if angular position is also used to account for a kind "slip angle" and introduce it in the closed loop algorithm. I am not an expert in motors but considering it has been said that torque is very linear with intensity I would presume that no encoder data is used to control intensity and hence the resolution of the encoder is irrelevant.
    A very different thing would be the servo system working in motion control mode (position/speed/acceleration) where a good position feedback is critical.

    Enviado desde mi GT-I9505 mediante Tapatalk
     
  13. Joe

    Joe Registered

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    Yes, if assume those tests were done with target currents aimed at same target speed but could be different moment of inertia (used different wheels) between AF and OSW (AF ends up at about 200 rpm while the OSW ends about 240 rpm), The OSW's resolution showed twice higher than AF's. In this testing with constant bursting, the best I can see on AF chart is at 100rpm = 6 degree per 10ms, while the OSW is 12 degree per 10ms. (note: 10ms is rFactor 2 FFB refresh time). If you rotating speed is larger then 6 degree, sorry the AF wheel will not output right torque. Anything below that it will perform same as OSW. So holding torque for AF would be just as good as OSW, but not turning fast than 6 degree per frame.
     
  14. DrR1pper

    DrR1pper Registered

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    Euskotracks, I think he was asking what affect (if any) those different encoder resolutions have on the steering angle input side of things.
     
  15. Marek Lesniak

    Marek Lesniak Car Team Staff Member

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    400Hz = 1000/400 = 2.5ms

    Exactly. Bear in mind, that in the end it does affect FFB sent by the sim. The more frequent and precise steering updates are, the faster and more accurately the sim will react to them.

    EDIT:
    Of course, at some point the precision might be well above what a simulator need so the question is, if 2500PPR (effectively 10000) is already enough? That's about 27.8 impulses per degree of an angle and that gives about 10 impulses per 1mm of turn for a 320mm wheel rim which is 1 impulse per 0.1mm. But can those encoders be 100% accurate? I don't think so. Probably readings are more like +/-1 impuse. In my opinion, it might not be *that* smooth. 5000PPR (20000) gives us 1 impulse per 0.05mm for that example.
    Kollmorgen's motors with 10000PPR give 0.025mm per 1 impulse :D
     
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  16. DrR1pper

    DrR1pper Registered

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    I think the peak speed differences are due to the imposed speed limits on each wheel by design.
     
  17. Euskotracks

    Euskotracks Registered

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    I was going to clarify that in terms of output to the sim, encoder resolution is relevant as long as it does not surpass rF2 bitfield.

    Enviado desde mi GT-I9505 mediante Tapatalk
     
  18. Joe

    Joe Registered

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    400Hz is rF2 Eng update rate, not API driver update rate.
     
  19. DrR1pper

    DrR1pper Registered

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    Ah ok. Know what it is for rf2?
     
  20. Marek Lesniak

    Marek Lesniak Car Team Staff Member

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    Then you should say clearly, you reffer to a connection via the plugin API. But still, ForceFeedback calls to InternalsPlugin interface run at 400Hz (info from ISI, so...). Telemetry is up to 100Hz.

    Not rF2 but USB controller is first on the line, before it. Typically, it's 16bit for the whole range, so for 1080deg it basically matches 5000PPR encoder. At that point, we might wonder if having twice as much precision on the encoder side, will make things better or not (considering, encoders might have reading precision of +/-1 impuse).

    EDIT:
    Then, we have Direct Input, which also operates at 16 bit precision.
     
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