An edge finder is a precision positioning tool that will locate the edge of the work in relation to the spindle centerline (axis) with up to 0.0002"/0.005mm accuracy when used properly. The figure and visuals below show the procedure and function of the edge finder, which consists of three steps:

A. Align the tip of the edge finder to the side of the part/feature you are attempting to locate. With the edge finder not touching the part, turn the spindle on at a moderate speed (~800RPM). The tip of the edge finder should wobble in this position.

B. Slowly feed the tip of the edge finder against the part. The tip will gradually reduce its wobbliness until it becomes concentric with the shank of the tool.

C. Keep feeding the edge finder into the part extremely slowly. When the tip becomes exactly centered, it will abruptly jump/kick sideways ~1/32" or ~1mm. The moment the tip kicks out, immediately stop moving the table. In this position, the spindle centerline is exactly half the tip's diameter away from the edge of the part. Move the table that exact amount to align the spindle centerline with the edge of the part. From here you can zero your dial/DRO and work from there.

Locating Round Features

Work Coordinate Systems

• With instructor guidance/supervision, discuss & demonstrate the following understanding/competencies:

  • Decide on & locate a WCS Origin (X/Y/Z Zero) for your D6 block, as well as the X/Y/Z locations of each feature of the block you will make