CNC Machine 3

Question 1

What does 'spindle runout' measure on a CNC machine?

Accepted Answer

The deviation of the spindle centerline from true rotation

Answer

Spindle runout is the radial deviation of the rotating spindle from its true centerline, which directly affects surface finish and tool life.

Question 2

In a CNC turning center, what is the purpose of the turret?

Accepted Answer

It holds multiple cutting tools and indexes them into position

Answer

The turret on a lathe holds multiple tools and rotates (indexes) to bring each tool into the cutting position without manual changes.

Question 3

What machine feature allows a CNC mill to tilt its spindle or table to machine angled features without repositioning the part?

Accepted Answer

4th or 5th axis (tilt axis)

Answer

A 4th or 5th rotary/tilt axis allows the machine to reorient the cutting tool relative to the part for complex angled surfaces in a single setup.

Question 4

Why is machine thermal stability important in precision CNC machining?

Accepted Answer

Thermal expansion changes machine geometry, causing dimensional errors

Answer

As machine components heat up, they expand and shift, altering the relative positions of the spindle and workpiece, causing out-of-tolerance parts.

Question 5

What is the role of a CNC machine's servo drive (amplifier)?

Accepted Answer

To convert low-power control signals into high-power motor commands

Answer

The servo drive receives position/velocity commands from the controller and amplifies them to supply the power needed to drive the servo motor accurately.

CNC - Cutting Practice Test

CNC - Cutting Practice Test

CNC Machine 3