Alphacam nesting guide: sheet layout, waste, grain direction and labels

Nesting places the parts to be machined onto as few sheets as possible with the least waste. Because board is the largest material cost in a furniture shop, a 3–5% difference in waste can equal a truckload a month. Alphacam Router nesting works from a part list, a sheet and a few rules; this article explains what each setting does and the tactics that work on the shop floor. Menu names vary by release.

Inputs: parts, quantity, sheet

• Parts: geometry with operations assigned (after Auto Style); each part a closed outer contour + inner operations.
• Quantity: per part, from the order list. A part needed 12 times is not drawn 12 times; the quantity is entered.
• Sheet: size (common 2,100 × 2,800, 1,830 × 3,660, 2,070 × 2,800 mm), thickness, margin (10–15 mm), material.
• Priority: large/critical parts placed first.

Label data (part name, order number, cabinet number) should be in the drawing before nesting; the Part Labelling macro (Cabinet Macros) writes it on the ETIKET layer and nesting carries it with the part.

Settings and what each does

Grain direction and rotation

On wood-grain melamine and veneered board the grain direction is an aesthetic rule: doors vertical, drawer fronts horizontal or vertical (project decision), carcass sides vertical. In nesting those parts are rotation-locked; only plain single-colour parts rotate freely. The lock increases waste — a deliberate cost. Grain is entered as a part property; if the macro marks door parts "grain vertical" when drawing, no manual setting is needed at nesting.

Small parts, vacuum and tabs

A vacuum table cannot hold a part smaller than about 0.05 m² (e.g. 200 × 200 mm) once the through cut completes; the part lifts and the cutter breaks. Fixes: tabs (1–2 mm thick, 6–10 mm wide, 2–4 per part), onion skin (leave the last 0.5 mm, break by hand), placing small parts in the strong central vacuum zone, or nesting small parts separately on offcuts. In Auto Style the tab rule is bound to part area: Alphacam Auto Style setup: automatic machining by layer name

Remnants

At the end of a nest, the unused part of the sheet can be cut as a rectangular remnant and stocked; Alphacam records it with its size and offers it before a full sheet in the next nest. Remnant management makes the waste figure real: a sheet showing "18% waste" drops to 6% when its 600 × 2,100 mm remnant is used on the next job. Print the remnant label (size + material) and stick it on the board.

Output: one NC per sheet and a label list

Each sheet becomes a separate drawing and NC file; the operator loads the sheet and calls its program. Labels are printed after nesting according to the sheet layout (label printer or on-machine labelling); the label is applied when the part comes off. What the post-processor does: What is an Alphacam post-processor? Producing NC code for your machine

Shop tactics for lower waste

• Combine orders: nest three small kitchens of the same material together, not separately — 4–8% less waste.
• Design to the sheet: on a 2,800 mm sheet two 1,380 mm sides fit, 1,400 mm does not — the 20 mm rule.
• Common line cutting only on straight-edged carcass parts; off for doors and patterned parts.
• Use remnants first, then full sheets.
• Check direction after nesting: rotated contours can end up with reversed cutting direction; Reverse Direction (GMacros) fixes all selected in one click.