[John Crombie] had a crack at building one using linear Hall effect ... sensor pair such that each sensor will report an equal mid-range signal with zero mechanical displacement. With some simple ...

Each unit is scratch-built, using laser-cut fiberboard for parts ... along with four stepper drivers and interfaces for the Hall-effect sensors needed to home each display. There’s also an ...

Even with Hall Effect sensors, I found that sometimes small movements would not be picked up by the controller —sometimes to ...