WorksheetsHealth, Safety, and CNC Equipment Types
Total questions: 15
Worksheet time: 8mins
Which regulation primarily governs safe use of work equipment in UK industry, including CNC machines?
CDM 2015 regulations for construction
REACH 2006 regulations for chemicals
PUWER 1998 regulations for work equipment
RIDDOR 2013 regulations for reporting
During proving-out of an untested CNC program, which hazard is most likely without proper single-block and feed hold use?
Routine tool life overestimation
Unexpected rapid crash into fixtures
Gradual thermal drift of spindle
Minor cosmetic surface staining
Which UK body is responsible for enforcing workplace health and safety, including machine safety inspections?
Health and Safety Executive (HSE)
British Standards Institution (BSI)
Institution of Mechanical Engineers
Department for Education (DfE)
Which pairing best matches engineering process to a common CNC machine used for it?
Drilling – wire EDM machine
Grinding – CNC vertical mill
Milling – surface grinder machine
Turning – CNC lathe machine
Which statement best compares CNC equipment with similar manual equipment?
Higher repeatability and automation, but higher setup complexity
Lower dimensional accuracy and slower cycle times overall
Similar repeatability with reduced programming overhead
Easier initial setup and cheaper tooling in most cases
Calculate a suitable spindle speed in revolutions per minute (rpm) for turning a 48 mm diameter steel bar if the recommended cutting speed is 210 m/min. Use the standard turning formula for spindle speed.
N = 1392 rpm for 48 mm diameter
N = 875 rpm for 48 mm diameter
N = 620 rpm for 48 mm diameter
N = 2785 rpm for 48 mm diameter
Calculate the absolute X and Y axis coordinate positions of a hole whose absolute polar coordinates are a radius of 35 mm at an angle of 28° to the horizontal.
X ≈ 30.9 mm, Y ≈ 16.4 mm
X ≈ 14.0 mm, Y ≈ 33.1 mm
X ≈ 16.4 mm, Y ≈ 30.9 mm
X ≈ 33.1 mm, Y ≈ 14.0 mm
Calculate the absolute polar coordinates (radius and angle) for a hole centre whose absolute Cartesian coordinates are X45.67 and Y39.45.
r ≈ 60.3 mm, θ ≈ 40.9°
r ≈ 52.0 mm, θ ≈ 28.0°
r ≈ 61.1 mm, θ ≈ 46.2°
r ≈ 75.1 mm, θ ≈ 32.5°
What is the meaning of the term modal function codes as used within a CNC program?
Codes that remain active until changed
Codes that execute only one block
Codes that start spindle rotation
Codes that set tool length offsets
Explain the role of preparatory functions (G codes) and miscellaneous functions (M codes) in CNC programming.
G codes control spindle; M codes define interpolation
G codes manage offsets; M codes set work coordinates
G codes define motion and modes; M codes control actions
G codes start coolant; M codes set feed rates
Which statement best distinguishes Manual Data Input (MDI) from a DNC link for loading CNC programs?
MDI enters short edits at the control, DNC streams long files
MDI streams large programs continuously, DNC types lines manually
MDI requires network cabling for transfer, DNC uses no cables
MDI always prevents syntax errors entirely, DNC cannot detect them
A shop downloads a CNC program via DNC and the machine executes garbled motions. Which pair is the most plausible cause of the incorrect data transmission?
Incorrect work offset measured after setup
Overly sharp cutting tool geometry used
Mismatched baud or parity settings on devices
Coolant concentration too high in reservoir
When setting up a new job, what is a key difference between a fixed machine datum and a user-defined floating datum?
Machine datum is built-in to the axes, floating datum is chosen on the part
Machine datum is set on the vise jaw, floating datum stays at machine home
Machine datum changes with each program, floating datum never changes
Machine datum must be G54, floating datum must be G28
Which purpose best describes why first-off inspection results should be recorded during manufacturing?
Enable traceability and corrective actions later
Replace the need for component specifications
Reduce machining time on all future batches
Guarantee zero defects for the entire production
A machinist must choose equipment for a first-off inspection of a tight-tolerance shaft. Which factor should most influence the selection?
Availability of the largest CMM room
Required measurement accuracy and resolution
Shortest setup time for the fixture
Operator preference for familiar brands
