Controlling Turtlebot's sound/noise

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Well, my experience with the IRobot Create is that it is loud. IMHO But I went as far as to examine the internals of the motors and drive-train and noticed that alot of the noise was due to plastic parts rubbing or touching inside. So I added some small plastic spacers inside the gear case to make some distance away from the motor gears and the encoders. Which I believe is where alot of the funny noise was coming from. But the trick is not to put too much distance away from the encoder and sensor so it still accurate. My turtlebot still makes noise but not nearly as loud as before. But I assume this mod will void your warranty and you may damage the gears,encoders, ect if you are not careful.. I mainly examined the noise due to the interference I was getting when trying to use TTSpeech with turtlebot. --Atom--

Most likely that noise is generated by the servo motor when the velocity command to the create is very small. When servo motors are driven at the low end of the controllable range typically they will make noises like you hear in the create. As you drive the create faster the noise should be less pronounced.

Also you can drive the motors at particular frequencies to produce different noises in general. For example you can make servo motors sing.... http://www.youtube.com/watch?v=-i9RyROVWHI

I've never heard a turtlebot make much noise, other than the motors. Creates make noise when they're turned on (I don't recall if the Turtlebot drivers make the robot make noise when they connect). But neither of those are "when it moves."

Can you explain further?