How parts become a cutting list

Each bench is one description of its parts, worked out afresh from your measures every time you change one. The model, the drawings and the cutting list are all read from that one description, so they cannot disagree with each other. A figure you type on the drawing changes the same measure as the rule beside it.

Every part is set down where it sits in the finished bench, with the timber it is made of and the timber cut out of it: mortises, sockets, holes. The drawings show both. The cutting list shows the blank you saw before any of that is cut.

The sizes in the list are finished sizes: the part planed and cut to length, with its tenons. A stretcher is listed at its length between shoulders plus both tenons. Where a part carries a trim allowance the source asks for, such as a joint left proud to be planed flush, the allowance is in the figure and the note under the part says so.

Length is along the grain. Width is the larger of the other two. Sizes are kept to the tenth of a millimetre, which is finer than a pencil line. In inches they are shown to the nearest sixteenth.

Parts that are the same piece of wood are merged into one row with a count. Rows run top, base, shelf, workholding, pegs, and within each the longest first. They are marked A, B, C in that order, and after Z, AA. The letter in the list is the letter in the balloon on the drawing, and the one to pencil on the timber. Bought hardware takes no mark and is listed last.

“Timber to buy” is worked from the finished list in four steps. Two of the four numbers are our judgement. The research found no source that gives a general figure for either, so neither is shown as tradition.

The sheet works in millimetres and shows millimetres or inches. Switching units changes how the figures are written. The bench stays the same. Roubo’s own units appear only as a read-out on his bench and in the labels of his bands.

The mass of a bench is the volume of its finished parts times the density of the timber: at 12 percent moisture content for the handbook timbers, and for the Australian ones WoodSolutions’ “seasoned” figure, whose moisture content it does not state. The timber cut out of the joints is not subtracted, so the figure reads a little heavy.

Southern yellow pine is a trade group of several trees, so it has three rows. A timber the research does not tabulate is left out; each row names its source in the last column.

A rule on a sheet is sourced when a book or a measured bench states it; the note names the book and the page or plate. It is derived when it is our arithmetic from sourced numbers, and it is our judgement when no source gives it at all. Each rule carries a tag saying which of the three it is.

These parts of the arithmetic on this page are derived:

• The height each sheet starts at: 0.45 of your height, held to the bench’s own range. That is the ratio of Schwarz’s own bench, 34 in, to his own stature, 6 ft 3 in. It rests on one man, who calls himself an outlier. The rule he actually gives is a measurement of your own body, and the sheet asks for it. The estimate is held between 711 and 990 mm and then inside each bench’s own range, and a height is good anywhere in a band of about 76 mm. Schwarz, 2020
• The density of the American timbers, from the handbook’s specific gravity at 12 percent.
• Board feet from cubic metres.

These are our judgement; no source gives them:

• The maker the site assumes before you say who you are: 1780 mm tall, working in millimetres.
• The timber a bench starts in until you choose one: the softwood most yards sell where you buy. That is radiata pine framing in Australia, loblolly southern yellow pine in the United States, and Scots pine, sold planed as redwood, in the UK and Europe.
• The 25 mm added to each length and the 15 percent added for waste.
• What a 1x board yields, and that a part up to 38 mm thick uses a 2x as bought.
• The least and greatest value of any measure where no source gives a range. The rules of each bench say which those are.

• How wet your timber is. Mass is at 12 percent for the handbook timbers. Construction timber comes from the yard wetter than that; buy early, stack it and wait. Schwarz, 2020
• Your merchant’s exact sizes. The yard lists for Australia, the United States and Britain are taken from merchants’ own pages; mills differ and no standard was consulted. Switch off what your yard does not keep, and check the finished size before you buy.
• The best layout of parts on boards. The cutting plan picks sections for the least timber bought and packs the lengths first-fit, longest first. That is close to the least, not always the least.
• Defects, grain and the board you will reject at the rack.
• What it costs, until you type in your yard’s prices.
• Anything the research could not source. Roubo’s plate was not measured, the museum’s measurements of the Moravian bench are not published, and paid plans were not read. Each gap is named where it bears on a measure.