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Topic: Controlling DC voltage to a linear actuator (Read 1 time) previous topic - next topic

ash901226

And using the formula of displacement over time you will get the speed.
Now what you should do is to base on your feedback of your choice, you should know how many tick of an incremental encorder, or the final value of the absolute encorder or linear pot.

Chagrin

An RC servo (or this actuator with an RC interface) doesn't have a feedback for actual position. You tell it what position you want it to move to and assume that it does actually move to that point. Your speed is then determined by how quickly you move it between positions.

If you don't like assumptions at all then you can buy their version which provides the RC control AND an analog output for position feedback. It is more expensive though, and IMHO overkill in this situation. Not having feedback is the same situation you'll see with millions of CNC machines with stepper motors; you can command them to "step" but (typically) can never verify that they actually do step.

Btw, to the OP, you might be going overkill using this linear actuator to move a syringe. A medium size RC servo that you'd find in a hobby store should have plenty of power to push a syringe. A quick google search reveals examples using that method.

zoomkat

Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

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