GlossaryKind of term: Manufacturing termCAM
What is CAM?
CAM is software that computes toolpaths from a geometric model and, through a postprocessor, turns them into an NC program for a specific machine.
CAM stands for computer-aided manufacturing. Programming a part runs in steps: you load the model, define setup, work origin and stock, choose tool, strategy and cutting data per operation, and the package computes the toolpaths. A postprocessor writes those paths out as an NC program for a specific machine and control. Most packages also simulate the paths and produce a setup sheet or tool list. The term is used more widely, for nesting software in laser cutting for instance; here it means machining.
What decides the result of a CAM program?
What comes out of CAM depends on the programmer's choices and on the models the package works with: the tool library with holders and overhangs, the machine model with axes and travel limits, the workholding and the stock. The more complete those models, the more a collision check or rest-material calculation is worth. The machining time CAM reports is calculated from path lengths and feeds; acceleration, tool changes, probing and override are left out or approximated. It is an estimate, not a measurement.
How does CAM work in practice?
Programming time belongs to the part and the revision, not to the piece. Estimates commonly book it as a one-off cost spread over the batch, so it weighs heavily on a single piece and less on a larger batch. A repeat order at the same revision can usually reuse the program, depending on machine and control; a new revision may need part of it again. At quote stage the CAM program usually does not exist yet, so programming time is itself an estimate. For complex parts some shops rough out a CAM job beforehand to back up the machining time.
What is CAM often confused with?
CAM is not CAD: CAD creates the shape of the part, CAM the movement of the tool. Many packages combine the two, but they remain different tasks. Nor is CAM the routing: the routing fixes sequence, machines and setups, CAM works out the operations within a setup. They do influence each other: a feature that proves unreachable in CAM can change the routing.
Frequently asked questions
Do I have to program in CAM before I can give a price?
No. Most quotes rest on an estimated programming time and an estimated machining time. For difficult parts a rough CAM job beforehand can prevent a large miss in machining time; whether that effort pays depends on the risk and the size of the order.
How reliable is the machining time from CAM?
It is calculated from path length and feed. CAM ignores or only approximates acceleration, tool changes, probing and feed override, so the actual time often differs. Machine simulation with a good machine model comes closer, but remains a prediction.
Does programming time count per piece or per batch?
Per part and per revision: the program is written once, however many pieces follow. How you spread the time is an estimating convention: usually over the batch of the order, sometimes over the repeat orders you expect.