Section 8 | Unit 1 Study Guide
Explain the benefits of using the absolute programming system versus the incremental system.
One of the disadvantages of using the incremental system is that any errors will accumulate. Absolute programming is typically less confusing and programming errors are less likely to be made.
What are the three parts of a CNC program?
Safe start, material removal, end program
Which coordinate system uses an angle and a distance to identify a position?
polar coordinate system
Explain the benefits of using the incremental programming system versus the absolute system.
The advantage to using the incremental method is that parts requiring repetitive motions can be easily computed and programmed.
Briefly describe a ball screw and a linear guide.
The ball screw is a screw and nut assembly with steel balls in place of threads, which can achieve high efficiency and zero backlash in CNC machines.
Explain the purpose of the safe-start portion of a CNC program.
The purpose of the safe-start portion is of a CNC program is to cancel any model codes are are unwanted and activate any that are necessary since modal codes remain active until canceled or overridden.
When a CNC lathe is equipped with an automatic tool changer it is called a ____.
Turning Center
What is another name for the Cartesian coordinate system?
rectangular coordinate system
What is the name of the character that ends each line of code?
end of block (semi-colon)
What is the name for the type of motor used to drive CNC axes that is also capable of recording axis position?
servo motor
CNC mills with an ATC are called ____.
machining centers
What is an ATC?
Automatic tool changer
What is a model code?
Codes that remain active until canceled or overridden are called modal codes.
List four G-codes and describe their functions.
G00 - Positioning at rapid speed G01 - Linear interpolation G02 - Circular interpolation clockwise G03 - Circular interpolation, counter clockwise
Name one positioning system and describe it.
Incremental positioning system which works by telling the distance from the current point to the next instead of going from the origin.
List four M-codes and describe their functions.
M03 - Spindle on clockwise M04 - Spindle on counterclockwise M05 - Spindle off M06 - toolchange
What is an MCU and is its function?
Machine control unit is the system of a CNC machine that interprets the program and then uses the info.
