How an Edge Finder Works

An edge finder works in the spindle of a machine, such as a mill.

An edge finder refers to tools used to determine markings or edgings to help pinpoint the center of a work piece. Edge finders, also referred to as center finders or wigglers, are used in some machine spindles.

Edge Finder Operation

The machine spindle or other rotating tool must rotate in order to activate the edge finder. The edge finder possesses a cone shape and is spring-loaded. When the finder touches the work piece it moves the cone, which is used to locate the center point of the piece relative to the edge.

Center Finder

A center edge finder is a pencil-like tool designed to locate markings on work pieces. Unlike standard edge finders, center edges do not possess a spring-loaded tip, and operates when the spindle is stopped, as opposed to in operation.

Electronic Edge Finder

An electronic edge finder, sometimes referred to as a digital edge finder, locates work piece edges, as well as height offsets. Electronic edge finders operate in a non-rotating spindle, is battery operated. It lights up via an LED, or light-emitting diode, when an electrical circuit is formed by the edge finder. The edge is found when the device reads a repeatability of .001.

References

• Toolingu: What is the definition of edge finder?
• "Machining Fundamentals"; John R. Walker; 2004

Resources

• "Machining: Fundamentals and Recent Advances"; J. Paulo Davim; 2008