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DIY 2DOF build project

Discussion in 'DIY Motion Simulator Projects' started by VictorS, Dec 21, 2020.

  1. VictorS

    VictorS New Member

    Joined:
    Dec 20, 2019
    Messages:
    5
    Occupation:
    Engineer
    Balance:
    60Coins
    Ratings:
    +1 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Hi everyone!

    I have an on going project where i'm building an 2DOF simulator.
    Capture render1.PNG
    The simulator was designed in CAD before ordering parts.

    The parts I'm using are:

    Motors:
    Heb35a4b876fa493ab21c141840629bc6I.jpg

    Model: 5D120GN-RV40
    Number of poles: 8
    Rated power: 120W
    Rated voltage: 24 (V)
    : 1800rpm
    Current: 7A
    Wormgear ratio 1:30
    Torque: 12,5 Nm

    Electrical components:

    Arduino UNO running SMC3
    ARDUINO UNO R3 SMD - Twins Chip 1-600x315w.jpg

    VNH5019 2 channel 30A motor driver board.
    Skärmklipp2.PNG
    Power supply 24V 16.5A 400W
    Skärmklipp3.PNG
    5K Ohm potentiometers
    316164.jpg

    The electronics were connected and the motors were tested in SMC3.
    Screenshot_20201221-170413_Snapchat 2.jpg

    Parts for the frame was ordered/manufactured and partially assembled.
    20200513_205724.jpg

    This is the current state of the project
    20201202_220632.jpg 20201022_165814.jpg

    I have tested the simulator with simtools and the axis/DOF seem to be correct.

    The problem I'm having is that the motors are jerking/juming a lot.
    I'm suspecting that the motors are not powerful enough or not mounted in the optimal position.
    If you have any suggestions/tips please help me.
    I'll keep you updated.
    • Like Like x 1
  2. Ads Master

    Ads Master

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  3. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
    Jul 13, 2014
    Messages:
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    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    122,676Coins
    Ratings:
    +9,684 / 47 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
  4. VictorS

    VictorS New Member

    Joined:
    Dec 20, 2019
    Messages:
    5
    Occupation:
    Engineer
    Balance:
    60Coins
    Ratings:
    +1 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Thanks!

    I think my rig is pretty well balanced, but I will try to balance it again.

    Resting angle is 90 deg.
    Capture.PNG
    Simtools settings:
    Capture2.PNG
    Capture3.PNG

    SMC3 settings:
    SMC3.PNG
    I've tried different values for PWMmax and PWMrev.

    I also downloaded SimCalc and entered my values, the forces seem pretty low right?
    Skärmklipp4.PNG
    Skärmklipp5.PNG

    I will try to film the rig the next time i'm testing it.
  5. VictorS

    VictorS New Member

    Joined:
    Dec 20, 2019
    Messages:
    5
    Occupation:
    Engineer
    Balance:
    60Coins
    Ratings:
    +1 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Also bought myself a Christmas present, can't wait to try it with the sim. :grin
    20201223_172627.jpg
  6. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
    Jul 13, 2014
    Messages:
    16,890
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    122,676Coins
    Ratings:
    +9,684 / 47 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
  7. Sam Neall

    Sam Neall Member

    Joined:
    May 14, 2019
    Messages:
    63
    Balance:
    84Coins
    Ratings:
    +13 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino, Motion platform
    Enjoy that wheelbase! I have the same one and it is really fun to use.
  8. Sam Neall

    Sam Neall Member

    Joined:
    May 14, 2019
    Messages:
    63
    Balance:
    84Coins
    Ratings:
    +13 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino, Motion platform
    Like noorbeast said, you should refine the motion profile when you want to test the motors. For example I have my axis allocation at 25%.
  9. VictorS

    VictorS New Member

    Joined:
    Dec 20, 2019
    Messages:
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    Occupation:
    Engineer
    Balance:
    60Coins
    Ratings:
    +1 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Did some testing today. It seems that the problem is not in the Simtools settings, I have the same problem when testing the motors in SMC3.

    I took some screenshots in SMC3 and a video to show you what's going on.

    This is the curve on PWMmax 90 and i slowly manually moved up and down:
    SMC3-Capture-6862.67916181pwm90.jpg.jpg
    This is the curve on PWMmax 120 and i slowly manually moved up and down:
    SMC3-Capture-6970.4731674pwm120.jpg

    I tried disconnecting the rods from the motor and still saw the same kind of pattern.

    PWMmax80, not connected to rig:
    SMC3-Capture-7154.985665599999-not-connect-pwm-80.jpg

    PWMmax40, not connected to rig:
    SMC3-Capture-7229.751322499999-not-connect-pwm-40_.jpg

    Here is a video from the tests:


    As you can see from the curves/video when the motor moves down the PWM curve spikes/jumps up and down and the motor shakes, same problem can be seen even with the rods disconnected. This happens for both motors.
  10. Sam Neall

    Sam Neall Member

    Joined:
    May 14, 2019
    Messages:
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    Balance:
    84Coins
    Ratings:
    +13 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino, Motion platform
    Ah, I have had this same exact problem with my simulator. The solution for me was to use the Ziegler Nichols method.

    You tune one parameter at a time and it will ensure smooth movement.
    Let me know how it goes.
    • Like Like x 1