CNC Coordinate Systems & Datum Setup 2

Question 1

How many standard work coordinate systems are available on most CNC controllers (G54 through G59)?

Accepted Answer

6

Answer

4

Answer

8

Answer

10

Question 2

What is the purpose of using G53 in a CNC program?

Accepted Answer

To temporarily move in machine coordinate space, bypassing active work offsets

Answer

To activate work coordinate system 3

Answer

To set the third fixture offset

Answer

To return the machine to program zero

Question 3

On a CNC lathe (turning center), the Z-axis zero point is most commonly set at:

Accepted Answer

The face of the finished workpiece

Answer

The center of the chuck jaws

Answer

The chuck face

Answer

The tailstock centerpoint

Question 4

What does the G10 command allow a programmer to do in a CNC program?

Accepted Answer

Set or modify tool offsets and work coordinate offsets within the program

Answer

Activate high-precision mode

Answer

Enable tool radius compensation

Answer

Switch between inch and metric units

Question 5

A 'datum' in CNC setup is best defined as:

Accepted Answer

A reference surface, point, or axis from which all measurements are made

Answer

The material removal rate of the cutting tool

Answer

The maximum cutting depth allowed per pass

Answer

The coolant flow setting during machining

Question 6

When a machinist uses G92 to set a new coordinate origin, what happens to the existing stored work offsets (e.g., G54)?

Accepted Answer

The coordinate display shifts so the current position becomes the new origin, acting as an additive shift on the active offset

Answer

They are permanently deleted from the controller

Answer

They are automatically backed up to G55

Answer

The machine homes itself first, then re-establishes offsets

Question 7

Which instrument is most commonly used to set the Z-axis tool length offset on a CNC machining center?

Accepted Answer

A tool presetter or Z-axis setter (height setter block)

Answer

A dial test indicator mounted on the spindle

Answer

A bore gauge measuring the spindle bore

Answer

A feeler gauge between the tool tip and table