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I'm looking for a linear actuator that can lift a microphone of about 700 grams. It's for a goose-neck microphone (together with shock-mount) that will pop out of a small pulpit. Only the top part is bent so it will stick out a small part when at the lowest position.

The electrical actuators I have found so far are made for heavy lifting and are far to slow (and noisy). I need to be able to adjust the height quickly when a different speaker comes.

What I'm looking for would be more like a printer head carriage in an ink-jet printer. It does not have to be that fast, 10cm/second would be good enough with a stroke of +/-45cm. It would be great if it could also send feedback on its position (or if it could be driven to a specific point like a servo).

Does anything like that exist off the shelf or would I have to custom-build the whole thing? I'm planning to use an Netduino+ (with a motor shield) to drive it.

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  • $\begingroup$ Counterweight held and released by an electromagnet. $\endgroup$ – Nick Alexeev Feb 8 '16 at 2:00
  • $\begingroup$ I'd go with hydraulics myself. $\endgroup$ – Carl Witthoft Feb 8 '16 at 12:15
  • $\begingroup$ @NickAlexeev Haha, or have a servo push a weight from a ledge... that surprised look on the face of a speaker when the pulpit does "Klunk", the mic jumps out and bounces a few times... no, maybe mounting an array of old cd-rom drives side-by-side and on top of each other so their drawers push the mic up when ejecting, or a home automation curtain mechanism... Seriously though, a linear actuator still seems to be the best fit so far. $\endgroup$ – Louis Somers Feb 9 '16 at 23:47
  • $\begingroup$ @CarlWitthoft I'm open minded, as long as I can hook up a Netduino+ (or other Ethernet interface) to control it. Do you have an example of something usable on the market? A search on hydraulic cylinder on Aliexpress did show some interesting results, but how would I drive it and what do I need to make a complete system, I'm missing some keywords. It looks like it might get messy with oil and so, but I'm all ears if you have a good example application. $\endgroup$ – Louis Somers Feb 9 '16 at 23:58
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If you're not set on the motor shield, you could use a stepper motor with a pulley instead, plus some form of linear guide (eg. an Igus slide, if you don't want it just dangling). Small Nema 17 size stepper motors easily generate enough torque to lift 700g, and you can use StepStick-style drivers, which can be driven easily from an Arduino.

If you need it to be very quiet, the SilentStepStick is a driver which is completely inaudible, while many other stepper drivers cause audible hum/buzz in the motors.

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    $\begingroup$ Thanks! You gave me the keywords I needed to get on with this project :-) $\endgroup$ – Louis Somers Feb 21 '16 at 1:51

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