Wednesday, May 29, 2013

6DOF platform photo with triple screen




UPDATE:

Many ask what kind of motors are these and what are their specifications. I'll provide here some link to these motors models and VFD inverters that were used for the 6DOF platform on the above photo.





AC motor (0.75HP) : MTR-P75-3BD18
GearBox (60:1)  :  WG-262-060-D
VFD inverter (1HP) : WJ200-007SF

Check their datasheet for more information to help you find similar equipment in your country.


PS. I provide the links and the models as reference only. I have no association with the above suppliers or vendors mentioned on the link.

Thanos
2013

19 comments:

  1. This is amazing!!! I have bought all of the stuff to build your old H bridge and amc 1.5 and I have wheel chair motors to make a 2dof joyrider style. I think I will build that for my little brother and start on this immediately. I posted on insidesimracing forums already but I will just post here again. Will you put of a list of the main hardware involved with this setup so that I may start purchasing the required hardware?

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  2. Thanks! It is the best ride for realistic motion cues.

    I'll make a post the next days with a proposed size motors, gearboxes and VFD's.

    I can tell you quickly some specifications:
    AC motor: 3phase, 220v, 0.75HP
    Gearbox: Worm drive, 60:1 (or 90:1 better)
    VFD inverter: 1phase input to 3phase output, 220v, 1HP


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  3. Hi Thanos,

    What is the sreen size ? 27 '' ?

    Regards

    Gilles

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    Replies
    1. You guessed right :)

      And you know how heavy they are!

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  4. Wouldn't a 90:1 gear drive make reactions slower? What do you think?

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    Replies
    1. Now that I think about it you might get a quicker response for higher frequency vibration effects with a higher ratio like 90:1 even though the max travel speed would be less.

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    2. As I wrote on the http://insidesimracing.tv/ forum, the way the motors share the motion allows you to pass vibration and perfect motion cues even with lower speed motors (higher gear ratio). A good RPM output from the gearheads should be in the range of 14-30 RPM)

      Best Regards,
      Thanos

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  5. I guess you liked the image! :D

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    Replies
    1. Yeap, nice job with the background removal! Thanks

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  6. Replies
    1. You mean the whole platform? Hmm...
      You can contact me on my email: tronickod@yahoo.com

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  7. Is this motion controller as fast as the one shown here?

    https://www.youtube.com/watch?v=zNUBZfrOXUc

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    Replies
    1. Actually, no. Its 100 times faster. In numbers, the PID loop runs 1000 times per second or 1Khz !

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    2. Well..yeah...(btw don't they have their sample rate at 50?)...but yours seems very fluid...but that might just be because flying is much more docile?

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    3. I think they may have 50hz updates, not sure, still way too slow to perform accurate PID on these servo motors they used. I think the cost for each servo motor for their sim was about $1800... That's why they needed at least $10000 as target for their Kickstarter "donation" project. How sad, tricked all these people to believe they were going to start a business but all it was was funds for their "school project"....

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    4. The AMC1280USB controller runs the motors smooth for flight simulation where there is hardly any vibration, but for car driving simulators you can get up to 300hz resolution vibration from the motors depending on the road conditions.

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    5. I have a stupid question...i don't really get why these motors have to be this big.
      Suppose you only have a person, pedals, steer and a seat to carry (i'm thinking oculus DK2 HMD)...couldn't you get away with making your own servo's out of readily available RC components. There are sensored brushless car motors that cost 30USD and can cope with 5KW! Having them geared down to say 30rpm and controlled with off-the-shelf controllers or even DIY fpga/uP solutions...could they not provide ample mechanical power to slush the payload around?
      I'm almost certain i'm not thinking this through...but i can't see the problem.

      I always assumed brushless motors basically start with the max torque...and that you could always gear down to go from speed to torque.

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    6. Its not stupid question. It might work, just never tried it. Just not sure about the reduction gearbox and also there is the issue of the refresh rate of these ESC drivers. As far a I know they accept pulses 20ms that is kind slow for PID. The PID needs fast reaction changes in speed and direction of the motor that for the AMC1280USB is 1000 times per second or 1khz or 1ms loop time. Unless you know any ESC and accepts PWM signal with direction inputs...

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    7. These days a lot of esc's do faster rates (333hz and even 1000hz i think) because of the way they are now important in quad-copter design control loops. The problem is the car esc's have yet to follow that route as there isn't really a need for them to be that fast.

      It might be possible to hook up two esc's to the same motor and do some simple PWM ucontroller code that only ever has one active...but that's really low tech and possibly very dangerous.

      If maybe i could build a servo that does not have fast update times...just as a proof of concept I might be able to get people on the RC forums on board to rewrite esc's code.
      Preferably using S-bus or some newer fully digital protocol instead of the dated pwm length prone to noise and jitter.

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