My eggbot pen servo was very touch sensitive – that is to say that the servo jumped around at the slightest and I do mean _slightest_ touch of its control wires.

Turned out the problem was with the Tower servo connector…it was a _very_ loose fit on the three-pin header, but the header itself was firmly soldered in place.  I’ve used plenty of servos, and know what the connectors should feel like.  I cut off the Tower connector, and spliced in a servo extension, and – presto!  A good fit, and no longer touch sensitive.  Woot!

The servo was still sealed in its factory wrapping, I think, when I got the kit – so it must have come from the factory in that pitiful state.