Work Holding & Fixturing Flashcards

What is the primary advantage of a hydraulic vise over a standard mechanical vise in CNC machining?

Answer: Consistent and repeatable clamping force

Hydraulic vises apply consistent, repeatable clamping force that reduces part-to-part variation and operator error.

A sine bar is used in fixturing primarily to:

Answer: Set precise angular orientations of a workpiece

A sine bar uses precision gauge blocks and trigonometry to set exact angular positions for workpieces during machining or inspection.

Which clamping method is most appropriate when a workpiece must be machined on all four vertical sides without re-fixturing?

Answer: A tombstone fixture on a horizontal machining center

A tombstone fixture mounted on a horizontal machining center allows B-axis indexing to access multiple faces in one setup.

What does 'pull stud' retention refer to in CNC toolholding?

Answer: The mechanism that draws and locks the toolholder into the spindle taper

A pull stud (retention knob) is threaded into the toolholder shank and is gripped by the spindle drawbar to secure the toolholder in the machine spindle.

When using parallels in a vise, their purpose is to:

Answer: Elevate the workpiece so it sits above the vise jaws for full feature access

Parallels raise the workpiece above the vise jaw top surface, exposing more of the part and allowing the cutter to clear the jaws.

A modular fixturing system's key advantage over dedicated fixtures is:

Answer: Rapid reconfiguration for different part geometries

Modular fixtures use standardized, reusable components that can be quickly rearranged to hold different parts, reducing lead time for new setups.

Which of the following best describes 'nesting' in CNC fixturing?

Answer: Using a locating pocket or feature that precisely positions the workpiece

Nesting involves a machined or cast recess in the fixture that the workpiece drops into, providing accurate repeatable location.