Glossary

The words this guide uses for machining and for the program. A page links a term here the first time it uses it.

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A axis

The fourth axis of a rotary machine: the turning of the work about the rotary axis. On the Makera Z1 it turns about X, and a positive A move turns the top of the chuck towards the front of the machine.

Air cut

A run of a program with no tool fitted and no material in the chuck, at reduced feed, to watch every move before anything can be damaged. See Air cut on the Makera Z1.

CAM

Computer-aided manufacturing: software that works out the moves a machine tool must make to cut a part from a model, and writes them as G-code.

Chuck

The clamp on a rotary machine that holds one end of the stock with its jaws and turns with the A axis.

Feed

The speed at which the cutter moves through material, in millimetres per minute. A rapid move travels through air at the machine’s fastest speed instead.

Feed override

A control on the machine that scales every programmed feed, for example to 10 % for a first run.

Finishing

Cutting the final surface of the part, usually with a smaller tool and close passes. See Roughing and finishing.

G-code

The text program a CNC machine’s controller reads: one move or setting per line, such as G1 X10 A90 F600. Each controller reads its own variant, which is why the program needs a post-processor.

Held region

A length at one end of the stock, measured along the axis, that the chuck or a tailstock grips. It is never cut, and toolpaths keep clear of it. The program knows it only as a length, not as a solid body, so it cannot check the chuck itself against the tool. See Stock and the held region.

Machine profile

The description of a machine the program uses: its axes, travel, the height and direction of the rotary axis, its feed limits and spindle speeds, and its post. Values nobody has measured on your machine are marked unconfirmed.

Material

What the stock is made of, such as hardwood or tooling board. The tool library holds cutting data for each material.

Operation

One step of the cutting: one tool, one strategy and its settings. A job is a list of operations, cut in order.

Post-processor

The part of the program that turns toolpaths into the G-code variant a particular controller reads. Often shortened to post. OpenChuckCAM includes a post for the Makera Z1 and one for LinuxCNC.

Project

A folder of plain text files that holds one job: the model, the setup, the tools and the operations.

Rotary axis

The line the work turns about. On the Makera Z1 it lies along X. See also A axis.

Roughing

Removing most of the material quickly, in layers, leaving a little for finishing. See Roughing and finishing.

Scallop

The small ridge a round-ended cutter leaves between neighbouring passes. See Stepover, stepdown, scallop and stock to leave.

Setup sheet

A page the program writes beside the G-code, listing the tools, the operations and a checksum of each program file, for the person at the machine.

Simulation

The program’s model of the material each operation removes, shown in 3D and compared with the part. See Simulation and deviation colours.

Stepdown

How deep each roughing layer goes.

Stepover

How far the cutter moves sideways between neighbouring passes. A smaller stepover leaves a smoother surface and takes longer.

Stock

The material you start with, such as a round bar or a block. The program cuts the part out of the stock, and needs its shape and size to know where material is.

Stock to leave

Material an operation leaves on the part on purpose, so that a later operation can finish it.

Strategy

The pattern in which an operation moves the cutter, such as helical finishing (a spiral round the part) or axial finishing (passes along the axis).

Tab

A small bridge of material left uncut so that the part stays attached to the stock until you separate it yourself. See Tabs.

Tailstock

A support that holds the far end of long work on a rotary machine. The program knows it only as a held region at that end.

Tolerance

How far a toolpath may stray from the model. The program’s default is 0.01 mm.

Tool library

The list of cutters the program knows. Each tool has a diameter, a shape and cutting data (a spindle speed and feeds) for each material. The default tools cannot be edited; you can copy one and change the copy.

Toolpath

The path the cutter follows, with the angle of A at every point, worked out by an operation.

Work offset

The register in the machine’s controller that stores where the part’s zero is, such as G54. You set it on the machine; the program writes its moves relative to it.