CNC Safety

Question 1

What personal protective equipment (PPE) is required when operating a CNC machine?

Answer 1

-Safety eyewear, footwear, and a protective shop coat.
-Hearing protection may be necessary.
-Restrain long hair under an approved shop cap.

Question 2

What clothing and accessories should be avoided when operating a CNC machine?

Answer 2

-Avoid loose clothing, neckties, gloves, watches, and rings.

Question 3

What should you do if injured while operating a CNC machine?

Answer 3

-Notify the instructor immediately.
-Apply first-aid to cuts and bruises.

Question 4

What precautions should you take in the shop environment?

Answer 4

-Keep the floor free from oil, grease, and chips.
-Remove tools and materials from the floor.

Question 5

What are some guidelines for handling CNC tools?

Answer 5

-Ensure tools are sharp and in good condition.
-Carry sharp tools safely to avoid injury.
-Use gloves or a thick rag when installing sharp tools.

Question 6

What is essential to check before operating any CNC machine?

Answer 6

-Confirm the location and operation of the Emergency Stop button.
-Make sure the machine is halted before entering the work envelope.

Question 7

What safety measures should you follow during CNC operation?

Answer 7

-Keep safety guards up before starting.
-Do not touch moving parts.
-Secure workpieces using adequate clamps or blocking.

Question 8

What are the steps for testing a new CNC program? (4)

Answer 8

(1) Graphically simulate the program.
(2) Perform a dry run for safety checks.
(3) Use single-step mode for the first cutting run, observing closely.
(4) Operate at full speeds and feeds only after a successful first run.

Question 9

What machining practices help ensure safety and quality?

Answer 9

-Check for obstacles in the machine’s working area.
-Verify tool position, height, and movements to avoid collisions.
-Use recommended cutting speeds and feeds.

Question 10

What is the recommended depth of cut for tools?

Answer 10

-Maximum depth of cut should be half the tool diameter.
-For tools under ¼” diameter, use less depth.

Question 11

What should you do to avoid chatter during milling?

Answer 11

Mill as close as possible to the work-holding device.

Question 12

Why should you avoid using an air hose to remove chips?

Answer 12

-Chips should be removed with a wire brush or proper T-slot tool to prevent chips from flying dangerously.
-Air hoses can cause chips to fly dangerously, creating a safety hazard.

Question 13

What documentation is necessary for a CNC setup?

Answer 13

-Cutting tools required.
-Fixture/holding methods.
-PRZ and Z-zero locations.
-Raw stock material and dimensions.
-Clamp locations.
-Sequence of operations.

Question 14

What actions should you take when machining a part for the first time?

Answer 14

-Warn observers before starting automatic operations.
-Supply a continuous flow of cutting fluid to carbide tools.
-Use reduced speed and feed for large-diameter or deep drilling.

Question 15

What should you do before entering the work envelope of a CNC machine?

Answer 15

-Make sure the CNC machine is halted.
-Press the Emergency Stop button for added safety.

Question 16

What should you avoid placing on the CNC machine table?

Answer 16

Do not place tools or materials on the CNC machine table. Use an adjacent worktable instead.

Question 17

What precautions should you take when grinding carbide or ceramic cutting tools?

Answer 17

-Grind only in a well-ventilated area.
-Do not grind near any CNC machine tool.

Question 18

What type of tool holder should you select to reduce insert breakage?

Answer 18

Select the thickest and shortest tool holder possible.

Question 19

What should you check before installing cutting tools?

Answer 19

Ensure all seating areas on tool holders allow the cutting tool to seat properly.

Question 20

What machining adjustments should you make for thread cutting operations?

Answer 20

Use slower speeds for thread cutting compared to other turning operations.

Question 21

How should you finish cut an internal taper?

Answer 21

Move the tool in the direction of the larger diameter.

Question 22

What should you do to the workpiece before handling it?

Answer 22

Check that it is free of burrs and particles.

Question 23

What precautions should you take when machining cast iron or steel with carbide tools?

Answer 23

Supply a continuous flow of cutting fluid.

Question 24

What steps should you take when drilling large-diameter or deep holes?

Answer 24

-Reduce speed and feed for large-diameter holes deeper than twice the drill size.
-Use a peck drill movement for deep holes of any size.

Question 25

What should you do before making the first cut on castings, forgings, or rough surfaces?

Answer 25

Make the first cut below the hard outer scale.

Question 26

How should you handle rapid movements during the first run of a CNC program?

Answer 26

Use reduced feed rates, especially for rapid moves.

Question 27

What should an operator do when the CNC machine is in operation?

Answer 27

-Never leave the CNC machine completely unattended. -Always be ready to react to stock movement, tool breakage, or other issues.

Question 28

What should you do in an emergency while operating a CNC machine?

Answer 28

Immediately press the Emergency Stop button to halt the machine.

Question 29

What is the purpose of the PRZ (Program Reference Zero) and Z-zero points in a CNC setup?

Answer 29

PRZ and Z-zero points help define the reference locations for accurate tool positioning and machining operations.

Question 30

What type of insert should you use for carbide or ceramic cutting tools?

Answer 30

Always use the thickest insert possible to improve durability and reduce breakage.

Question 31

Why is single-step mode important during the first program run?

Answer 31

It allows the operator to observe machine motion, clearances, and potential issues step-by-step, ensuring safety and preventing damage.