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Question 2DOF with Parkinsons

Discussion in 'DIY Motion Simulator Building Q&A / FAQ' started by James Robbie, Sep 18, 2019.

  1. James Robbie

    James Robbie Active Member

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    My Motion Simulator:
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    First off - I am not making fun of Parkinson's or people with Parkinson's disease

    BUT, this is the best way I can describe what my 2DOF SMC3 Wiper Motor set up is doing. When sitting at "idle", the motor just sits there and instead of finding centre and holding it, it bounces back and forth ever so slightly and just shudders. When i am using it, the motor moves as you would expect and is smooth etc.

    IT IS HIGHLY FRUSTRATING

    The only way I have been able to get around it is dropping my PWMmax to about 100/110. I can keep my PWMrev at approx 200 and PWMmin is approx 50. KP is set to 500.

    If i set my PWMmax to what my ideal setting of 200ish, it just shakes uncontrollably.

    Anybody else had similar trouble? Any suggestions?
  2. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

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    My Motion Simulator:
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    How is the pot connected and does the gearbox have backlash?
  3. James Robbie

    James Robbie Active Member

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    My Motion Simulator:
    2DOF, DC motor, Arduino, Motion platform
    Pot is connected via a 2:1 ratio 3D printed gear set. Gears are butted up against each other tight

    Minimal backlash, I wouldn't say there is plenty but there is minimal movement. Backlash induced you reckon?

    20190919_000803.jpg
  4. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

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    My Motion Simulator:
    3DOF, DC motor, JRK
    That or PID settings.
  5. James Robbie

    James Robbie Active Member

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    Occupation:
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    My Motion Simulator:
    2DOF, DC motor, Arduino, Motion platform
    Fpid is currently set to 2, worth changing that to 4 maybe? Will that have a negative effect being 1/4 of the calcs per second? Surely it would only "dull" the data...