Deck 6: Programming Concepts and Job Planning

Question 1

Why do complicated drawings take so long to understand?

Answer 1

Complicated drawings can take hours to fully comprehend. You need to understand the form of each feature, its relationship to other features, and the implication of the tolerances before planning any machining operations. For example, you might notice a hole in the center of the workpiece. What kind of hole should this be? Should you drill the hole, ream it, or bore it? Can this hole be milled with an end mill or is a counterbore the proper tool to use? All of these questions are based on the specified tolerances and the required quality of the finished feature. Failure to understand these relationships will lead to wasted time and a scrapped part.

Question 2

The NC part program is made up of distinct units of instruction called ____.

A) words
B) addresses
C) logistics
D) blocks

Answer 2

D

Question 3

What are the two types of codes found in an NC part program?

Answer 3

There are two fundamentally different types of codes found in an NC part program. The first type of code controls machine functions and settings. The second type of code is used to modify and perform machining functions. The arrangement and use of these codes will form the fundamental structure of the part program.

Question 4

What is the difference between modal and non-modal codes?

Question 5

____ compensation automatically offsets the tool from the programmed path.

A) Length
B) Tool radius
C) Drilling
D) Cyclic

Question 6

Provide some guidelines for developing efficient workpiece setups.

Question 7

Most programs today are written on modern, PC-based computers with a text editor that makes it very easy to copy and paste redundant code and to make changes at will.

Question 8

Toolpaths are difficult to plot because we have to manually compensate for the ____ of the tool.

A) volume
B) material
C) radius
D) length

Question 9

The geometry of the finished workpiece will be the ultimate measure of the success or failure of your programming.

Question 10

____ pins are cylindrical pins that have been ground slightly oversized.

A) Clearance
B) Bearing
C) Dowel
D) Reaming

Question 11

The key to properly locating a workpiece is a principle called ____.

A) 3-2-1
B) datum
C) the primary principle
D) referencing

Question 12

In the end, it does not really matter where you put the work zero as long as it is kept in the proper relation to the locating surfaces.

Question 13

A(n) ____ is a reference plane or point that is defined on the engineering drawing from which other dimensions are established.

A) address
B) word
C) letter
D) datum

Question 14

The term ____ describes codes or values that stay active until changed by another code or value.

A) word
B) modal
C) part program
D) address

Question 15

Rough, cast, and saw-cut surfaces must usually be ____ before they can be used as locating surfaces.

A) drilled
B) qualified
C) fixed
D) curved

Question 16

What is the first step in planning and executing a CNC machining job?

A) Determining which tools are available
B) Writing the part program
C) Studying the workpiece drawing
D) Planning the operations and setups

Question 17

On most raw materials, the stock faces are relatively flat and square from the mill.

Question 18

We know from our study of the Cartesian coordinate system that any location in the first quadrant will have ____ coordinates.

A) positive
B) negative
C) irrational
D) imaginary

Question 19

What information should be included in the program's comments?

Question 20

Modern CNC machine tools can be programmed to perform machining operations with a language commonly referred to as H & N codes.