Cnc Pt. 2.0 Feb/ 2020 Flashcards
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:
M:
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?
Advantages:
- Easier cutting action for soft metals like aluminum
- Less horsepower required to run cutter
Disadvantages:
- Only have edges on one side of insert
What are some of the advantages and disadvantages of a negative rake angle on cutting inserts?
Advantages:
- Machine harder materials and interrupted cuts
- Inserts have twice as many edges
Disadvantages:
- 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.
Group