Manufacturing costing engine for process planners and estimators: physics-based cutting time T = L/(f·n) per pass, rapid-traverse, tool-change and handling times, setup amortization over the batch, and a full unit-cost build-up — machine hour rate, attended labor, material, overhead and profit margin — with parts-per-hour, batch-size sensitivity and cost-composition charts. Every input with selectable universal units and reference-standard values, every report with the full audit trail.
SectorCalc SC-023 turns process parameters into a defensible unit price. Cutting time comes from physics — length, feed and RPM — not from guesswork; non-cutting time is itemized (rapids, tool changes, load/unload); setup is amortized over the batch; and the cost build-up stacks machine hour rate, attended labor, material, overhead and margin into a selling price. Batch-size sensitivity shows exactly how much a small order really costs. Results are reference-grade estimates — final quotations must reflect your actual cost accounting and commercial policy.
This is the only part of the cycle that adds value, and the only part the feeds-and-speeds engine (SC-020) can shorten. Doubling feed halves cutting time — until surface finish or tool life objects. The extra cutting time field folds in drilling, tapping (SC-022) and milling operations estimated elsewhere.
On small parts, load/unload and tool changes routinely exceed cutting time. A 4-second turret index on a 30-second cycle is 13 % of capacity; an operator walking to a pallet rack is pure loss. Itemizing these times is the first step of any SMED or automation business case.
A 45-minute setup adds 27 seconds per part at batch 100 but 4.5 minutes at batch 10 — often doubling the small-batch price. The sensitivity chart quantifies this so you can defend minimum-order quantities or justify changeover reduction investment with numbers.
Machine hour rate (from SC-038) carries depreciation, interest, space, energy and maintenance. Labor is charged only for the attended share via the manning factor — 0.5 for one operator running two machines. Overhead is applied to conversion cost plus material as a single allocation.
Margin is applied on the price basis (12 % margin ⇒ price = cost/0.88), the convention that survives discount negotiations intact. Markup-on-cost and margin-on-price diverge fast above 20 % — the report states which basis is used so sales and costing read the same number.
Setup amortization. Check the batch-size chart: below the knee of the curve, setup dominates. Either enforce a minimum order quantity, charge setup as a separate line, or invest in changeover reduction.
Practices differ. This engine applies overhead to material + conversion (full absorption) but margin to the total, which is the conservative common practice. If your policy excludes material from overhead, reduce the overhead input accordingly.
From SC-038 (Machine Hour Rate Calculator): purchase price depreciation, imputed interest, floor space, energy and maintenance per planned operating hour. Never use the purchase price divided by warranty years — that understates the true rate by 30–50 %.
Set manning to 0.25 (attended only during tending windows) and increase load/unload to reflect robot cycles. The machine rate usually stays constant; the labor line collapses — that difference is the automation business case.
