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Does anyone know if small mechanical actuators exist which can be controlled electrically, sort of like a miniature joystick, but in reverse. Instead of it picking up mechanical movement and outputting electrical signals, I want it to generate mechanical movement controlled via my electrical input signals. I’ve searched for : electromechanical actuators, not finding what I need. Think of a pencil attached to a surface which can pivot to point anywhere in its half dome. I’m thinking small, on the order of an inch. It will not be load bearing.

My goal is to programmatically control the normal pointed to by a small flat surface attached to the end of each joystick rod. Accuracy is more important than speed. From across a small room, say 10' by 10', I'd like the surface normal to accurately point to arbitrary objects in the room, say a person walking across the room. If I can cheaply buy/build such mechanisms to control the movement of these small flat surfaces, I would like dozens places across the walls of the room.

Its for an electromechanical sound project I’m planning.

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  • $\begingroup$ Thanks Event Horizon, that's sounds like an interesting project. It sounds like a tough set of requirements to do cheaply though, especially if you want lots of them. Hopefully people can come up with a some possibilities for you. $\endgroup$
    – Mark Booth
    Mar 11, 2013 at 13:22
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    $\begingroup$ +1 to both Andrew Wagner and mimipc's answers. You will need to build your 2-degree-of-freedom actuator out of two separate 1-degree-of-freedom actuators, either in a polar coordinate (pan/tilt) or cartesian coordinate (x axis / y axis) system. sparkfun.com/tutorials/304 might have the image of what you're trying to describe. $\endgroup$
    – Ian
    Jan 31, 2014 at 20:27

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The device you are looking for is a "pan-tilt" unit. They are typically used for pointing security cameras. If you find a "PTZ", i.e. pan-tilt-zoom security camera used, you could butcher it an just use the Pan/Tilt part.

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  • $\begingroup$ yes that's the term I am looking for: Pan/Tilt Bracket - thanks $\endgroup$ Jan 31, 2014 at 20:49
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You could do this using two servos (one for each axis). Here is what I mean (sorry for the poor graphics) :

Edit : trying to find the original image and upload it.

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  • $\begingroup$ The diagram is great mimipc. Whatever actuator is used, the same physical mounting as you describe could be used translate a small actuator movement into a movement of the tip within the hemisphere of movement. $\endgroup$
    – Mark Booth
    Mar 8, 2013 at 10:15
  • $\begingroup$ @mimipc cool thanks - this morning I was thinking of a similar possibility - I will try using a servo approach $\endgroup$ Mar 8, 2013 at 13:53
  • $\begingroup$ @EventHorizon - Don't be too quick to judge an answer. By accepting mimipc's answer, you may discourage other solutions. Given the coupling, there could be other ideas which are be easier to control than this one. $\endgroup$
    – Mark Booth
    Mar 8, 2013 at 16:22
  • $\begingroup$ I agree with Mark Booth. This was just an idea and it has some limitations. For example, it doesn't allow much movement, and is not a complete hemisphere. The zone is pretty much a restricted cone. $\endgroup$
    – mimipc
    Mar 8, 2013 at 16:25
  • $\begingroup$ It looks like the images you uploaded here have been replaced with advertisements by ImageShack. Do you have backup copies, by any chance? $\endgroup$
    – user2015
    Aug 25, 2015 at 5:50

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