CNC Machine Safety 5

Question 1

What is the safest method for removing a broken end mill from a CNC spindle taper?

Accepted Answer

Use the machine's drawbar release function with the spindle fully stopped

Answer

The machine's drawbar release is the correct mechanical method for releasing a tool holder safely, always performed with the spindle confirmed stopped.

Question 2

Which of the following describes a 'two-hand control' safety device used on some CNC punch or press operations?

Accepted Answer

A device requiring simultaneous activation of two controls to initiate a hazardous motion

Answer

Two-hand controls require both hands to be on controls simultaneously, ensuring the operator's hands are clear of the hazard zone before the machine cycles.

Question 3

What is the greatest danger of leaving a CNC machine unattended while it is running an automated cycle?

Accepted Answer

A fault, crash, or fire may go undetected and escalate

Answer

An unattended machine cannot be stopped quickly when a fault, tool breakage, or fire occurs, allowing a minor event to escalate into major damage or injury.

Question 4

How should long bar stock that extends beyond the headstock of a CNC lathe be handled safely?

Accepted Answer

Enclose or guard the protruding stock and use a bar feeder or steady rest

Answer

Bar stock extending past the headstock can whip at dangerous speeds; a bar feeder, steady rest, or full enclosure prevents this from injuring bystanders.

Question 5

What role does a CNC machine's spindle orientation (M19) command play in safe tool changes?

Accepted Answer

It locks the spindle at a fixed angular position so the tool key aligns correctly

Answer

M19 orients and locks the spindle at a precise angle to ensure the tool-holder key aligns with the spindle drive slots during automatic or manual tool changes.

CNC - Cutting Practice Test

CNC - Cutting Practice Test

CNC Machine Safety 5