1. Do not share user accounts! Any account that is shared by another person will be blocked and closed. This means: we will close not only the account that is shared, but also the main account of the user who uses another person's account. We have the ability to detect account sharing, so please do not try to cheat the system. This action will take place on 04/18/2023. Read all forum rules.
    Dismiss Notice
  2. For downloading SimTools plugins you need a Download Package. Get it with virtual coins that you receive for forum activity or Buy Download Package - We have a zero Spam tolerance so read our forum rules first.

    Buy Now a Download Plan!
  3. Do not try to cheat our system and do not post an unnecessary amount of useless posts only to earn credits here. We have a zero spam tolerance policy and this will cause a ban of your user account. Otherwise we wish you a pleasant stay here! Read the forum rules
  4. We have a few rules which you need to read and accept before posting anything here! Following these rules will keep the forum clean and your stay pleasant. Do not follow these rules can lead to permanent exclusion from this website: Read the forum rules.
    Are you a company? Read our company rules

Anyone used linear displacement sensors on their motion rig?

Discussion in 'DIY Motion Simulator Building Q&A / FAQ' started by hoopstar, Aug 11, 2016.

  1. hoopstar

    hoopstar when 10/10ths isn't enough..

    Joined:
    May 20, 2009
    Messages:
    15
    Occupation:
    Electronic Engineer
    Location:
    Adelaide
    Balance:
    49Coins
    Ratings:
    +0 / 0 / -0
    Hi Guys

    I am slowly piecing together parts for my seat mover motion rig.

    Today at work I was chatting with our chief mechanical design engineer trying to pick his brains for any improvements in my design. He's an amazing talent who's been around forever and pointed out a few things and really got into the whole 'simulator' concept.

    An hour later he comes up to me with a couple of these linear displacement sensors that are used in various motorsports for datalogging suspension movement which are surplus to our needs (used on an older design). :)

    IMG_7789.JPG

    They are a 5K potentiometer with 125mm stroke with a guaranteed +/- 0.15% linearity, a maximum shaft velocity of 10m/s and life expectancy of 200 million cycles.

    position.jpg

    On paper, they seem like the perfect thing for a motion rig but was wondering if anyone has use such a beast on their rig?

    Is tracking linear position of the seat 'push rods' better or worse than gearbox motor rotation (ie hall pot)?

    What advantages or disadvantages are there with each type of pot (ie. linear Vs rotational)?

    Cheers

    Paul
  2. SilentChill

    SilentChill Problem Maker

    Joined:
    Jul 19, 2014
    Messages:
    2,619
    Occupation:
    Railway Maintenance
    Location:
    Morecambe, Lancashire, England
    Balance:
    20,395Coins
    Ratings:
    +3,480 / 34 / -0
    My Motion Simulator:
    DC motor, Arduino, Motion platform, 6DOF
    125mm stroke is too short for a rig like mine but a very good idea for shorter throw rigs :)
  3. BlazinH

    BlazinH Well-Known Member

    Joined:
    Oct 19, 2013
    Messages:
    2,145
    Location:
    Oklahoma City, USA
    Balance:
    16,568Coins
    Ratings:
    +1,831 / 32 / -1
    I think there should be an advantage using linear sensors with a rotational actuator because they will measure the non-linearity of the movement. A pot attached to a motor shaft appears to have linear movement even though it isn't. A pot would require an algorithm to accurately measure non-linear movement.

    Edit: That is assuming levers are being used.
    • Agree Agree x 1
    Last edited: Aug 11, 2016
  4. RacingMat

    RacingMat Well-Known Member Gold Contributor

    Joined:
    Feb 22, 2013
    Messages:
    2,233
    Location:
    Marseille - FRANCE
    Balance:
    20,875Coins
    Ratings:
    +2,079 / 21 / -2
    My Motion Simulator:
    2DOF, DC motor, Arduino
    is it a "Linear Variable Differential Transformer"?

    in this case, it is a top quality, >100$ piece of equipement
    which would suit perfectly for simulator use
  5. BlazinH

    BlazinH Well-Known Member

    Joined:
    Oct 19, 2013
    Messages:
    2,145
    Location:
    Oklahoma City, USA
    Balance:
    16,568Coins
    Ratings:
    +1,831 / 32 / -1
    I wouldn't be surprised from their specs that they would be expensive.
    • Agree Agree x 1
  6. hoopstar

    hoopstar when 10/10ths isn't enough..

    Joined:
    May 20, 2009
    Messages:
    15
    Occupation:
    Electronic Engineer
    Location:
    Adelaide
    Balance:
    49Coins
    Ratings:
    +0 / 0 / -0
    Our design engineer said they cost 'a couple of grand each'... Sounds a little high to me but we're a defense company and we never seem to buy anything cheap :)

    @SilentChill - I will be running the Motion Dynamic motors with 60mm CTC levers so figured these 125mm sensors would be sufficient. What stroke are you running?