Woodworking Machinery and Machine Setting
This domain tests machine selection, correct setting and the safety logic behind each adjustment. Typical questions give a component and ask for the machine, the setting values and the reason. Numbers matter: blade projection, depth of cut, feed direction, knife marks.
Saw bench
- Blade projection 3–5 mm above the work: enough to clear the teeth, not enough to expose the gullet.
- Riving knife 3–8 mm behind the blade, set 1–5 mm below tooth height, in line with the blade.
- Crown guard and push stick; use a push stick whenever the work is within about 300 mm of the blade.
- Fence parallel to the blade, checked at front and back; a fence that is out of line causes burning and kickback.
Planer and thicknesser
- Surface the face side first with light cuts (about 1 mm), alternating ends, until the board sits without rock; then plane the face edge square.
- Thicknessing: maximum 2 mm per pass in hardwood, 3 mm in softwood; feed against cutter rotation.
- Snipe at the ends is reduced by supporting the stock and by correct infeed/outfeed roller pressure. Planing knife projection is generally 1.0–1.5 mm above the block, set to the outfeed table.
Spindle moulder
Tooling: rebate block, grooving cutter, tenon disc, limiters. Spindle speed 6000–9000 rpm matched to cutter diameter. Feed against rotation; guard with a ring fence and pressure fingers; power feed for narrow work. Never climb cut on a moulder.
Bandsaw
Blade width sets the minimum radius: narrow blades for tight curves, wide blades for straight resawing. Guides set to about 0.1 mm clearance; correct tension; track the blade on the crown of the wheel.
Drills, mortiser, lathe, CNC
Slower speeds for larger bits and larger diameters; clear chips; clamp work. CNC setting starts from a known datum and a test cut.
Worked example
A planer has a 3-knife block running at 4500 rpm and a feed of 6 m/min. Cuts per minute = 4500 × 3 = 13,500. Feed per knife = 6000 / 13,500 = 0.44 mm, so there are about 25 / 0.44 = 56 knife marks per 25 mm - a clean finish. Double the feed to 12 m/min and the spacing becomes 0.89 mm (about 28 marks per 25 mm), which shows as visible ripple on the surface.
Traps that cost marks
Thicknessing before one face is flat; feeding with the rotation; removing the riving knife for a rebate; setting knives above the outfeed table; fitting too wide a blade for a tight curve; standing in the kickback line.
Quote the setting value and the reason together - examiners award both.