CNC Machine 2

Question 1

What does the term 'backlash' refer to in a CNC machine's lead screw system?

Accepted Answer

The lost motion between the screw and nut due to mechanical play

Answer

Backlash is the small amount of lost motion caused by the gap between mating lead screw and nut threads, which can cause positioning errors.

Question 2

Which CNC machine component converts rotary motor motion into linear table movement?

Accepted Answer

Ball screw

Answer

Ball screws convert the rotary motion of a servo motor into precise linear movement of the machine table or axis.

Question 3

On a CNC machining center, what is the purpose of the automatic tool changer (ATC)?

Accepted Answer

To store and swap tools into the spindle without manual intervention

Answer

The ATC stores multiple tools in a magazine and automatically exchanges them in the spindle, reducing cycle time and manual intervention.

Question 4

What machine parameter describes the maximum distance an axis can travel from its home position?

Accepted Answer

Soft limit (travel limit)

Answer

Soft limits are programmable boundaries set in the controller that prevent axis travel beyond the machine's physical range.

Question 5

A CNC router experiences chatter marks on a flat pocket. Which machine-related cause should be investigated first?

Accepted Answer

Worn or loose spindle bearings

Answer

Worn or loose spindle bearings allow radial runout that causes chatter and surface finish defects, especially during milling operations.

CNC - Cutting Practice Test