Wasting

Question 1

Define wasting (simple).

Answer 1

Processes that REMOVE material to create shape/size/finish, e.g., sawing, drilling, turning, milling, grinding, laser/plasma/waterjet cutting.

Question 2

Cutting vs shaping—difference in one line.

Answer 2

Cutting/wasting removes material as chips/kerf; shaping changes form without removal (e.g., bending/rolling).

Question 3

Three checks before any wasting operation.

Answer 3

Secure workholding, choose the correct tool/speed, and clear guards/extraction are on; wear eye protection.

Question 4

What is swarf and why manage it?

Answer 4

Chips/kerf produced during wasting; must be cleared/extracted to prevent recutting, heat build‑up and hazards.

Question 5

Hand hacksaw—two setup tips.

Answer 5

Fit blade with teeth pointing forward and tension correctly; clamp work close to the cut to reduce vibration.

Question 6

Bandsaw—what guides and speed affect.

Answer 6

Guide position controls blade stability; blade speed and pitch must suit material to avoid burning or tooth loss.

Question 7

Sheet cutting safety (guillotine/shear).

Answer 7

Keep fingers behind guards and hold‑downs; never cut narrow strips with hands near the blade—use push tools.

Question 8

Pilot drilling—why use it?

Answer 8

A small pilot keeps the larger drill on centre, reduces load and improves hole accuracy.

Question 9

Give two reasons to use a centre punch before drilling.

Answer 9

Locates the drill and prevents wandering on flat or curved surfaces.

Question 10

Peck drilling—purpose.

Answer 10

Short retracts clear chips and reduce heat, especially in deep holes.

Question 11

Countersink vs counterbore—difference.

Answer 11

CSK = conical recess for flat‑head screws; C’BORE = flat‑bottom recess for cap screw heads/washers.

Question 12

Reaming—when and why.

Answer 12

After drilling undersize to achieve accurate diameter and improved finish for dowels/bearings.

Question 13

Simple tap drill rule for metric threads.

Answer 13

Tap drill ≈ major diameter − pitch (e.g., M6×1 → 6−1 = 5 mm).

Question 14

Name four wasting operations on a centre lathe.

Answer 14

Facing, turning (profiling), parting‑off, and drilling/boring (also grooving and threading).

Question 15

Lathe datum setting—two quick steps.

Answer 15

Face the end to set Z0 on the face; touch off on diameter and set X to known value/diameter.

Question 16

Parting‑off—two safety tips.

Answer 16

Keep tool on centre height and square to the work; use appropriate cutting fluid and clear chips frequently.

Question 17

Milling—two common 2D toolpaths.

Answer 17

Pocketing (remove inside material) and contour/profile (cut the outside).

Question 18

Climb vs conventional milling—school‑level note.

Answer 18

Climb can give better finish on rigid CNC; use conventional on loose/manual setups to reduce grab/backlash issues.

Question 19

Router sheet cutting—why add tabs?

Answer 19

Small bridges hold parts during through‑cuts to prevent movement or tip‑ups.

Question 20

Grinding—what does grit size control?

Answer 20

Surface finish and stock removal rate; finer grits give smoother finish but remove slower.

Question 21

Bench grinder two rules.

Answer 21

Keep tool rest close to the wheel (≈1–2 mm) and use the guard; do not grind on the wheel side unless rated.

Question 22

Abrasive finishing—two examples.

Answer 22

Hand filing and sanding/emery to remove burrs and improve edge quality.

Question 23

Laser cutting—what is kerf?

Answer 23

The width of material removed by the beam; compensate with correct offset/nesting for accurate sizes.

Question 24

Laser cutting H&S—two key points.

Answer 24

Use extraction; never cut PVC because it releases corrosive/chlorine fumes.

Question 25

Plasma vs laser—simple difference.

Answer 25

Plasma uses an electric arc on conductive metals with larger heat‑affected zone; laser uses focused light with finer kerf.

Question 26

Waterjet—one advantage for metals and plastics.

Answer 26

Cold cutting with minimal heat‑affected zone and no melting/burning of edges.

Question 27

Chip load concept (simple).

Answer 27

Amount each cutter tooth removes per revolution; affects feed, heat and tool life.

Question 28

Basic feed formula (concept).

Answer 28

Feed (mm/min) = chip load per tooth × number of teeth × spindle RPM.

Question 29

Step‑over and step‑down—effect on outcome.

Answer 29

Smaller values improve finish and accuracy but increase machining time.

Question 30

Two signs of tool wear while wasting.

Answer 30

Poor surface finish/burr formation and increased noise/heat or burning marks.

Question 31

How to reduce burrs on milled edges.

Answer 31

Use sharp tools, correct feeds/speeds, climb cut for finishing, and add a light deburr/spring pass.

Question 32

Post‑process finishing—three methods.

Answer 32

Deburring (hand/file), countersinking edges, and abrasive finishing (sanding/scotch‑brite).

Question 33

Two checks after wasting a precision bore.

Answer 33

Measure diameter with a plug gauge/reamer size and verify surface finish/roundness if critical.

Question 34

Best practice for dimensioning holes on drawings.

Answer 34

Use hole callouts with size, depth and type (e.g., Ø6 THRU; Ø10 C’BORE Ø16×5; M6×1 TAP ×12 DEEP).

Question 35

Name three workholding methods for wasting.

Answer 35

Vice with parallels/soft jaws, clamps/fixture plates, and chucks/collets for round work.

Question 36

Lock‑out/guarding—why important on powered cutters?

Answer 36

Prevents accidental start and shields users from moving tools/beam exposure and ejected swarf.

Question 37

Choose a process: cut 5 mm acrylic profiles to shape in a class set.

Answer 37

Laser cutting with correct power/speed and extraction; allow for kerf and leave protective film to reduce marks.

Question 38

Choose a process: produce a precise Ø6 dowel hole.

Answer 38

Drill 5.9–5.95 mm then ream to Ø6 H7 for size and finish.

Question 39

Choose a process: remove 2 mm from a steel bar face to length.

Answer 39

Face on the lathe or use a mill with a sharp end mill; measure and approach in light passes for accuracy.

Question 40

How can good wasting practice reduce TIMWOOD wastes?

Answer 40

Correct feeds/speeds and sharp tooling reduce Defects/Overprocessing; nests/fixtures cut Waiting and Motion; accurate nesting reduces Inventory waste in sheet cutting.

Question 41

Two pre‑use checks on a pedestal drill.

Answer 41

Chuck key removed and guard in place; correct speed set for drill size/material.

Question 42

Why deburr after wasting?

Answer 42

Sharp edges can cut hands, scratch assemblies and affect fit—deburring improves safety and quality.