need help with rc motor, with constant rotation

Discussion in 'General Electronics Chat' started by rfwalker, Nov 24, 2009.

  1. rfwalker

    Thread Starter New Member

    Nov 24, 2009
    3
    0
    Hi all, I need some help. I do not know much about rc servos but am leaning towards using one to accomplish my goal.

    basically I want a linear actuator that extends 8 to 12"
    and will continuously extend/retract slowly (.2 or .3"/sec), and will have no load.
    something like
    http://www.firgelliauto.com/images/flashpicis/track-actuator.gif
    would be ideal. but I can't spend that much and not sure I am competent to program it.

    I basically want to turn it on and have it extend/retract until turned off, unless I can use a PC interface to program it (something simple)

    because the above is so expensive, I was thinking of using a rc servo motor attached to a belt of some type to get the linear motion.

    but looking at phidgets rc motors, they state you have to remove a pot and replace with 2 resistors to trick it to go into continuous operation,
    so I am wondering if all rc are like this, I just simple want to be able to
    tell the rc motor to turn on and rotate at some velocity and don't stop
    till I tell it to

    can someone please help, I have been searching for a week and investigating linear actuators and don't think that fits the need either

    thanks, if there is a better/bigger forum where this could be answered, please send them my way. thanks rfwalker@hotmail.com

    happy thanksgiving
     
  2. ifixit

    Distinguished Member

    Nov 20, 2008
    639
    108
    How about a length of treaded rod attached to a simple, reversable, AC or DC motor. A nut would run up and down the rod at a constant rate if the motor speed was constant.

    The nut would have to be stabilized with guide rails to prevent it from turning and could hit a micro-switch at each end that would trigger a relay/circuit to reverse the motor direction.

    Good Luck
     
  3. rfwalker

    Thread Starter New Member

    Nov 24, 2009
    3
    0
    thanks,
    can I ask another favor, can you recommend some parts

    I guess I need
    1) the screw/threaded rod
    2) the nut that can be held somehow from rotating
    3) a constant ac motor that can be reversed with flip of switch/circuit
    4) limit switches

    where do I get this, or at least could you be a bit more specific so I can
    search for google with some more specific parts
     
  4. ifixit

    Distinguished Member

    Nov 20, 2008
    639
    108
    Items 1 & 2 you'll have to figure out yourself so that the results will suit your exact needs. (Google: threaded rod)

    You could use a 'drill driver' to turn the threaded shaft. Buy a cheap one or a used one and modify to suit. (Google: drill driver)

    The reversing switch on the drill would have to be re-wired so that it gets toggled at each end by the Nut. This will be a bigger mechanical challenge than an electrical challenge.

    Study all about circuits by clicking here: http://www.allaboutcircuits.com/vol_1/index.html

    Good Luck
     
  5. rfwalker

    Thread Starter New Member

    Nov 24, 2009
    3
    0
    thank you, will start the google hunt
     
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