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Very fast linear actuator

  1. Jul 12, 2012 #1
    I am working on a project that requires moving a 100mm long and <.5mm diameter pin a specific distance in a straight line. I want to move the pin in and out as fast as possible and accurate to less than .05 mm. The device needs to be as small as possible. The stepper linear actuators on the market appeared to be a good option but they look too slow and expensive. I was looking into using the electromagnet from a speaker, but I am not sure how to calculate the speed and accuracy of the push/pull. Any advice would be helpful. Thanks.
  2. jcsd
  3. Jul 13, 2012 #2
    I also need to have each push to have a different and controllable distance.
  4. Jul 13, 2012 #3
    I once had to design a lenses switching system in a very high dollar optical system that hangs under an F16 jet. I used a lead screw with 5 leads. Put a very expensive anti friction coating on the threads and spent a great deal of money eliminating nearly all the back lash. System has been operational for three decades with nearly no trouble. Used a standard high end stepper motor.
  5. Jul 13, 2012 #4
    Let's see...you want:
    • "fast as possible"
    • "straight line" motion
    • "small as possible"
    • but not "too slow and expensive"
    • "accurate to less than 0.5mm"...oh, wait, that's definitive

    It might help to be more precise in your specifications.

    I have many ideas, but they all violate one or more of these vague requirements. Or, at least what I may consider fast or slow or small or expensive or straight.

    Look at linear servo motors, rotary cam-follower systems, lead screw systems, or piezo-electric actuators.
  6. Jul 16, 2012 #5
    i just learned about rotating linkages, so my opinion might be bias, but you can translate rotational motion in to linear motion with one of those (if you need it to move over and over at the same speed)
    this is obviously not a good solution if you need the pin to move only once or twice per minute, or something
  7. Jul 16, 2012 #6

    jim hardy

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    Gold Member

    hmm i'd look at how the heads were positioned in large diskdrives of 1980's.
    They used "Voice Coil Drivers" with closed loop position measurement.

    Google search on 'voice coil disk head' brought up a lot of information.

    Siliconix Si9961 is a typical driver there'll be application notes.

    and you might find an old disk drive surplus.
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