Cnc Pt. 2.0 Feb/ 2020 Flashcards Preview

AIT 2019 QH-V2 > Cnc Pt. 2.0 Feb/ 2020 > Flashcards

Flashcards in Cnc Pt. 2.0 Feb/ 2020 Deck (53)
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Which of the following does the P stand for in the code G71 P_Q_U_W_D_S_F_; ( rough turning and boring repetitive cycle ) in relation to CNC repetitive cycle programming?

a) amount of material that is left on the Z faces for the finish cut

b) amount of material left on the diameter for the finish cut

c) block number of the first tool motion from tool park location for machining the finish profile

d) block number of the last tool motion completing the part profile and closing the repetitive cycle loop

c) block number of the first tool motion from tool park location for machining the finish profile


The following G10 command block for a Fanuc control, what does the letter " L " stand for? N__G10 L_ R_T_:?

a) tool orientation number

b) value of the tool nose radius

c) type of offset

d) block number


c) type of offset



CNC " G " codes are properly grouped by which of the following?

a) According to their function

b) on their sequence

c) on their number of significant digits

d) their bit size


a) According to their function



Which one of the following bar shapes is held in a three-jaw chuck?

a) Hexagonal

b) Octagonal

c) Square

d) 10 sided


a) Hexagonal


What is the advantage of using soft jaws in a 3 jaw chuck?

a) The work-piece will always run true

b) The jaws do not have to be machined

c) Rough unfinished surfaces can be held

d) Very long unsupported work-piece can be held


a) The work-piece will always run true



What is the name given to the centre that is located in the headstock spindle when working between centers?

a) Ball-bearing centre

b) Rotating centre

c) Live centre

d) Spinning centre



c) Live centre



Which of the following is an important machining principle or concept?

a) Knurl the work-piece last

b) Rough before you finish 

c) Turn chamfers after threading

d) Do not lubricate dead centers


b) Rough before you finish ( Heeheehee ) 


What happens when the tail-stock centre is offset?

a) The work-piece will be bent

b) The work-piece will not turn

c) The work-piece will have parallel diameter

d) The work-piece will have tapered diameters


d) The work-piece will have a tapered diameters



How should a reamer be removed from a finished hole?

a) Increase the spindle speed, before removing the reamer

b) Run the reamer backwards for a few seconds

c) Remove the reamer before stopping the machine

d) Switch the machine off


c) Remove the reamer before stopping the machine



How do reamer manufacturers try to reduce the possibility of chatter during a reaming operation?

a) By making the reamer from softer metal

b) By making the reamer from harder metal

c) By staggering the spacing of the teeth

d) By spacing the teeth equally


c) By staggering the spacing of the teeth



What is one of the differences between a hand and machine reamer?

a) Hand reamer have a very short starting or lead taper

b) Hand reamers have a very long starting or lead taper

c) Hand reamers always have tapered shanks

d) Hand reamers always have straight flutes


b) Hand reamers have a very long starting or lead taper



Why are reamers used?

a) To finish machine holes to a specific diameter

b) To rough out a hole ready for final finishing

c) To produce elliptical holes in steel

d) To burnish a hole to a high shine


a) To finish machine holes to a specific diameter



What material are reamers normally made from?

a) High-speed steel

b) Cubic boron nitride

c) Aluminum oxide

d) Ceramics


a) High-speed steel



What is the basic definition of the following letters?



G: Preparatory function

M: Miscellaneous function


What are the remedies when working on a lathe for Crater wear on your cutting tool?



- Use a grade with more wear resistance

- Lower cutting speed

- Reduce feed rate



What are the advantages and disadvantages of positive rake angles on inserts?



- Easier cutting action for soft metals like aluminum

- Less horsepower required to run cutter


- Only have edges on one side of insert



What are some of the advantages and disadvantages of a negative rake angle on cutting inserts?



- Machine harder materials and interrupted cuts 

- Inserts have twice as many edges


- More horsepower required



The resolution of a CNC machine is defined as:


The smallest slide movement the machine control can identify and act upon


A bit is used to:


Turn on or off parameters



During rapid Traverse, the operator and programmer have to:


Ensure safe movements to avoid machine crashes



Preparatory codes of the same ____ can't appear on the same block.





What is tolerance?


Total permissible variation in size of a dimension, intentional difference in size of mating parts


Checking the pitch of a thread can be done most accurately with the:


Pitch gauge



What can you do if you were cutting hard materials and your cutter keeps breaking?


- Increase the negative rake, which helps protect the tool when machining hard materials and interrupted cuts.


The amount of metal left for removal by a hand reamer is generally?


- .005"


To have a dimension with a bilateral tolerance you must have:


- A dimension with both plus and/or minus from the basic size


List three types of knee and column Milling machines:


a) Plain horizontal

b) Universal horizontal

c) Vertical



Positive rake cutting allows: 


- Allows chips to flow freely away from The Cutting Edge


The coordinate system that is based on two or more axis perpendicularly, intersecting each other at the point of origin is the: 


- Cartesian coordinate system


The cutting speed for reaming as compared to drilling a given material is about what?


- 1/2 - 2/3


The machine reamer that cuts only at the chamfered end is called a: 

- Rose chucking


List two safety precautions for a power hacksaw: 


- Solidly mounted workpiece, and guards



The radial face of the tooth of a reamer is located:


1/64" before the centre



Which of the following Cutters is not suitable for Helical Milling?

a) single cutter

b) side and face cutter

c) double angle cutter

d) helical cutter


b) side and face cutter



Name eight ( 8 ) operations which can be performed on a milling machine:


a) Facing

b) Straddle

c) Gang

d) Sawing and slitting

e) Indexing

f) Drilling

g) Rack milling

h) Rotary table



When Milling a spiral reamer which method of indexing is used?


Simple indexing



The up feed method of milling gives a better work finish and the cutters retain their sharpness.

a) True

b) False


b) False



A set of gear cutters consist of ____ cutters.


- Eight ( 8 )



The size of a horizontal boring mill is judged by the?

- Diameter of the spindle bore.



A boring mill that has a table that travels in a longitudinal and transverse direction is called: 

- Table type


Which of the following operations is rarely performed on a horizontal boring mill?

a) End milling

b) Gang milling

c) face milling

d) single-point cutting tool

b) Gang milling



Identify the thread designation:

3/4 - 10 UN C - 2 A

3/4 = Major Diameter

10 = Pitch

UN = Thread Form

C = series

2 = Class of Fit

A = External



The size of a vertical boring mill is determined by the: 


The size of the table.



What process is used to heat steel to just above it's lower critical temperature, hold for long enough for the structure to change to austenite then quench the steel quickly enough that it turns into martensite instead of perlite?


- Hardening


What must you always do to hardened steel?


- Temper it to remove stresses and restore toughness.


What process is taking steel and reheating it to a temperature somewhere below it's lower critical temperature and then allow it to cool slowly? 

- Tempering.


What process do you heat the steel to just above it's upper critical temperature, allow it to soak so that the temperature is consistent and then allow it to cool very slowly?


- Full annealing, which makes hardened steel soft again. 


What process is to heat the steel to above it's upper critical temperature and then allowed to cool slowly in still air?


- Normalizing, which improves the grain structure of the steel.



What are the processes of heat treatment of steel?


a) Hardening

b) Tempering

c) Full annealing

d) Normalizing

e) Case hardening ( if you want to include that s*** )


What are the six colour changes for heated steel?


a) Light straw

b) Dark straw

c) Brown

d) Purple

e) Violet

f) Dark blue


The milling machine attachment that changes rotary to reciprocating motion is the? 

- Slotting attachment



The endmill that can always be used for plunge milling into a solid material is the: 

- 2 fluted endmill


To ensure the safe operation of a grinding machine, what must you do: 


- The wheel should be sharpened and dressed as often as is needed.