Pancyprian TS Wood & Furniture III flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Moisture content formula

MC% equals wet mass minus oven-dry mass, divided by oven-dry mass, times one hundred. Indoor furniture timber in Cyprus is normally specified between eight and twelve percent.

Equilibrium moisture content

The moisture level timber settles at for a given air temperature and relative humidity. Heated rooms can drive it to five to seven percent, causing further shrinkage after delivery.

Tangential versus radial shrinkage

Timber shrinks about twice as much tangentially as radially. This differential explains why flat-sawn boards cup, with the concave face away from the heart.

MDF moisture behaviour

Medium density fibreboard machines and profiles cleanly and takes paint well, but swelling from water absorption is irreversible, so it is unsuitable for wet or exterior locations.

First-angle projection

The view from above is placed below the front view and the view from the left appears on the right. Confirm the convention on the title block before machining.

Section hatching convention

Cut solid material is shown with thin lines at about forty-five degrees. Adjacent components in the same section are hatched in opposite directions so the joint reads clearly.

Cutting list allowances

Cutting lists state species, finished size, quantity and grain direction, plus machining allowance: typically three to six millimetres on width and thickness and ten to twenty on length.

Workshop material flow layout

Machines are sequenced in the order material travels: storage, crosscut, rip and surface, jointing, assembly, finishing. Keep eight hundred to one thousand millimetres clear at infeed and outfeed.

Bench plane sharpening angles

A bench plane blade is honed at twenty-five degrees with a thirty-degree micro-bevel. Chisels use twenty-five for paring and thirty for chopping to resist edge crumbling.

Cap iron setting

Setting the cap iron roughly zero point three to zero point eight millimetres from the cutting edge breaks chips and reduces tearout on difficult grain during bench planing.

Circular saw riving knife

The riving knife must sit within three to eight millimetres of the blade and below tooth height, preventing the kerf closing and causing kickback during rip cuts.

Router feed direction

Feeding against the bit rotation is conventional and controllable for edge profiling. Climb-cutting with the rotation is reserved for light finishing passes because it can self-feed.

Planer outfeed table setting

On a surface planer the outfeed table is set level with the cutter at top dead centre, or one to one point five millimetres lower per pass, to control depth and avoid snipe.

Table saw fence alignment

The rip fence is set parallel to the blade within about zero point one to zero point two millimetres over the table length; misalignment causes burning and kickback.

Spindle moulder cutter rating

Cutter blocks must be round, balanced and rated for the spindle speed used. Feed against rotation and keep hands at least three hundred millimetres from the cutters.

Band saw guide setting

Blade guides are set about zero point five to one millimetre behind the tooth gullets, with tracking centred on the wheel and tension matched to blade width.

Dovetail slope ratios

Dovetail pins and tails are laid out at about one in six for softwoods and one in eight for hardwoods, with half-pins at each edge roughly half a pin wide.

Mortise and tenon proportion

Tenon thickness is about one third of the rail thickness. A haunched tenon is used where the rail is reduced so the mortise does not break through the face.

Frame and panel movement allowance

A solid panel must be two to three millimetres smaller than the groove depth all round, so seasonal expansion does not split the frame or force the panel out.

Biscuit joint spacing

In eighteen to twenty millimetre board, biscuit centres are spaced about one hundred to one hundred fifty millimetres, set eight to ten millimetres below the surface.

Sanding grit sequence

Bare timber is sanded eighty, then one hundred twenty, then one hundred eighty, and two hundred forty on hardwoods, always with the grain, removing each scratch pattern before the next.

Removing raised grain

Dampening the sanded surface raises crushed fibres. Once dry, sand lightly with the grain before the first coat to prevent a rough, fuzzy finish.

PVA open and clamp time

PVA adhesive has an open time of roughly five to ten minutes and needs clamping for thirty to sixty minutes. Polyurethane foaming adhesive cures with moisture and expands.

Oily hardwood preparation

Teak, olive and similar oily species are degreased with solvent before gluing or finishing, otherwise adhesive bonds and coating adhesion fail at the surface.

Dining table ergonomics

Dining tables are seven hundred twenty to seven hundred fifty millimetres high with seats at four hundred thirty to four hundred fifty, leaving a hundred fifty to two hundred clearance.

Kitchen base unit dimensions

Base units are typically five hundred sixty to six hundred millimetres deep and seven hundred twenty high before the worktop, which sits at eight hundred fifty to nine hundred.

Percentile design rule

Design reach limits to the fifth percentile so the smallest user can reach, and clearances to the ninety-fifth percentile so the largest user fits comfortably.

Upholstery foam densities

Seat cushions use foam of about thirty-five to forty kilograms per cubic metre; back cushions use twenty-five to thirty. Webbing or springs sit at one hundred to one hundred fifty centres.

Hardwood dust hazard

Hardwood dust is a recognised carcinogen linked to nasal cancer. On-tool extraction and local exhaust ventilation are required at sanding and machining stations, not optional.

Noise action values

The lower exposure action value is eighty decibels A-weighted and the upper is eighty-five. Above the upper value, hearing protection and health surveillance are required.

Risk control hierarchy

Controls are applied in order: eliminate or substitute the hazard, then engineer guards and extraction, then administrative controls, with personal protective equipment as the last resort.

Unit cost build-up

Unit cost equals material plus labour plus machine overhead plus finishing plus waste allowance. Waste runs about ten to fifteen percent on solid timber and five to ten on panels.