Integration of Hall Sensor in a 3D Printer as a Limit Switch

The 3D printer is a three-dimensional prototyping machine which fabricates desired shape by layer over layer material deposition. The printer's extruder should be at its homing position before any deposition process begins. Also keeping the deposition process within the specified limits of movement is very vital. The precise positioning of the extruder can be done using limit switches. This paper focuses on using a hall sensor as a limit switches and comparing its advantages over conventionally used intrusive sensors (mechanical switches). If the movement of the extruder is not within the given workspace, undesirable dimensional changes may happen in the end product. Conventionally the positioning is done by using mechanical switches which may undergo wear and need a regular replacement. The limit switch is an electromagnetic device which restricts the movement of the extruder outside the permissible limit. The limit switch detects the motion of the machine parts and sends feedback to the controller which in turn control the machine. When compared to a opto switch, the device is relatively cheap with all the desired characteristics including no wear.