A CNC setup is more than turning a part over. It is the controlled transition between a machine, workholding arrangement, coordinate system, tool set, program state, and inspection approval. Each additional setup adds labor and queue time, but its larger effect may be on datum transfer, tolerance risk, first-piece verification,
CNC unit price usually falls as quantity increases, but the curve is not a simple volume discount. The first part carries programming, process planning, workholding, setup, first-off verification, and purchasing effort that later pieces can share. Larger orders may justify better fixtures, automation, bar feeders, tombstones, in-process probing, or more
STEP AP242 can carry much more than a part’s visible shape. Depending on the authoring system, export options, protocol edition, and receiving application, an AP242 file may transmit precise geometry, assembly structure, names, colors, saved views, and product manufacturing information (PMI) such as dimensions, tolerances, datums, and surface requirements. That
“Aluminum,” “stainless,” or “PEEK” is not a complete material requirement for a CNC quotation. A useful CNC RFQ material callout identifies the grade, metallurgical or polymer condition, product form, governing specification, required evidence, and rules for substitution. Those details influence stock availability, mechanical properties, residual stress, cutting behavior, dimensional stability,
A 3D model can show a machine shop what the part looks like, but it rarely tells the whole manufacturing and inspection story. A quote-ready 2D production drawing establishes the controlled requirements that are difficult, ambiguous, or inappropriate to infer from CAD alone: tolerances, datums, threads, surface texture, material condition,
When a machine shop asks for a 3D model, the practical question is not which file extension is “best” in the abstract. The question is which file the supplier can import without changing geometry, losing product structure, or misunderstanding the released revision. For most CNC RFQs, STEP is the safest