What is the definition of "radius method"?
A method for programming circular tool movements that requires an R code to indicate the size of the arc's radius. The radius method is best used for partial-arc motions.

## CNC Training

Class Information
 Tooling U classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
 Class Name: Milling Calculations 295 Description: This class explains the common calculations necessary to plot the toolpaths for a basic milling program. Prerequisites: 300130  300140  800210 Difficulty: Intermediate Number of Lessons: 17 Language: English, Spanish

Below are all the competencies and job programs that contain the class Milling Calculations 295. Job programs are our traditional class lists organized according to common job functions. Competencies are our latest job-specific curricula that help tie online learning to practical, hands-on tasks.

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Competencies Show All

Class Outline
• Objectives
• The Purpose of Toolpath Calculations
• Program Zero Location
• Face Milling Calculations
• The Face Milling Toolpath: Y-Axis
• The Face Milling Toolpath: X-Axis
• Pocket Milling Calculations
• The Pocket Toolpath
• Spot Drilling Calculations
• The Spot Drill Toolpath
• Drilling Calculations
• The Drilling Toolpath
• CRC on the Mill
• Full-Circle Milling Calculations
• The Full Circle Toolpath
• The Bolt Hole Pattern
• Summary

Class Objectives
• Describe the basic elements of a toolpath.
• Identify the appropriate location for program zero on a part.
• Explain the general rules that govern face milling calculations.
• Calculate the Y-axis locations for a common face milling operation.
• Calculate the X-axis locations for a common face milling operation.
• Explain the general rules that govern pocket milling calculations.
• Calculate the initial coordinates to begin a boxing routine for a rectangular pocket.
• Explain the general rules that govern spot drilling calculations.
• Calculate the depth required to leave a chamfer with a spot drill.
• Explain the general rules that govern drilling calculations.
• Calculate the depth required to completely drill a hole.
• Explain a common method for removing ramping motions from a program’s toolpaths.
• Explain the general rules that govern full-circle milling.
• Calculate the starting locations for matching full radius and arc in motions.
• Calculate the coordinate location of a hole in a bolt-hole pattern.

Class Vocabulary

Vocabulary TermDefinition
A slight distance added to a toolpath at the beginning of a cut for safety reasons.
A method for programming circular tool movements that requires an I code and J code to indicate the location of the arc's center along the X- and Y-axes. The arc center method is best used for full-arc motions.
A partial-arc motion that leads into a larger arc motion. Arc in and arc out motions leave a smooth surface finish.
A partial-arc motion that exits from a larger arc motion. Arc in and arc out motions leave a smooth surface finish.
A common specification on milled parts that requires a series of equally spaced holes around the circumference of a larger imaginary circle.
A series of increasingly larger rectangular toolpaths used to machine a rectangular pocket.
Computer-aided design/computer-aided manufacturing. CAD/CAM is the use of software to aid in the design and manufacturing of a part.
A small, angled surface added to an edge of a workpiece. A chamfer removes the sharp edge and helps eliminate burrs.
Any useful space that is intentionally maintained between components.
A part feature that is non-linear, or curved.
The numerical system that describes the location of an object by numerically expressing its distance from a fixed position along three linear axes. The coordinate system consists of the X-, Y-, and Z-axes.
In a right triangle, the ratio of the length of the side adjacent to the angle divided by the hypotenuse.
An offset used on the machining center that accounts for variations in tool diameter. CRC is only necessary for tools that continuously cut along a horizontal plane.
The unintended movement or repositioning of a component due to a mechanical force. Deflection of a cutting tool can cause poor surface finish and inaccurate dimensions.
A thin, tall mill cutter with a flat bottom and cutting edges that wind up the sides. Both the bottom and side of the end mill provide cutting surfaces during milling operations.
A flat mill cutter with multiple cutting teeth surrounding the tool. The bottom of the face mill is primarily the cutting surface during milling operations.
A milling operation in which the surface of the workpiece is perpendicular to the spindle axis. Face milling primarily is used to mill the top surface of the part.
A final cutting pass that produces the necessary surface finish and brings a feature to its proper size.
The small amount of material that is intentionally left for a finishing pass.
In a right triangle, the side located opposite the right angle.
For circular interpolation, the program code that indicates the location of the arc's center along the X-axis. I and J codes are used for the arc center method.
For circular interpolation, the program code that indicates the location of the arc's center along the Y-axis. I and J codes are used for the arc center method.
A ratio describing the length of a cylindrical tool or workpiece compared to its diameter. Higher length-to-diameter ratios offer less rigidity.
Any multi-point tool that is used to remove metal from the surface of a workpiece.
A series of instructions used by a CNC machine to perform the necessary sequence of operations to machine a specific workpiece.
An interior recess that is cut into the surface of a workpiece. Pockets may be round or rectangular.
The position that acts as the origin for the part program of a particular workpiece. This position is unique to each workpiece design, and it is selected by the part programmer.
For circular interpolation, the program code that indicates the length of the arc's radius. In certain canned cycles, an R code indicates the R level for tool return.
A method for programming circular tool movements that requires an R code to indicate the size of the arc's radius. The radius method is best used for partial-arc motions.
A linear motion of the tool that is required for a control to adjust for a particular tool offset.
In a right triangle, the ratio of the length of the side opposite the angle divided by the hypotenuse.
A short, sturdy drill used to start a hole and accurately locate it. Most spot drills have a 90° tip.
The size of the cutter's diameter that is engaged in a cut. The step-over should be 75% to 80% of the cutter's diameter.
A part that can be divided by a line into two equal halves, with identical features that are equal distances from the dividing line. Both sides appear as mirror images of each other.
In a right triangle, the ratio of the length of the side opposite the angle divided by the adjacent side.
The series of coordinate positions that determine the movement of a tool during a machining operation.
The branch of mathematics that addresses the measurements and relationships of a triangle and its parts.
An offset used on a turning center and some machining centers that allows for the slight adjustment of tool tip location. Wear offsets account for part deflection, tool wear, etc.
On the mill, the linear axis representing coordinate positions along the longest distance parallel to the worktable.
On the mill, the linear axis representing coordinate positions along the shortest distance parallel to the worktable.
On the mill, the linear axis representing coordinate positions perpendicular to the worktable. The Z-axis is always parallel to the spindle.