Which type of motor is not used in axis or spindle drives of CNC machine tools?
Induction motor
DC servo motor
Stepper motor
Linear servo motor
Correct Answer :
C. Stepper motor
Related Questions
During the execution of a CNC part program block NO20 GO2 X45.0 Y25.0 R5.0 ; the type of tool motion will be
Circular Interpolation − clockwise
Circular Interpolation − counter clockwise
Linear Interpolation
Rapid feed
Ultrasonic machining is best suited for
Tool steels
Sintered carbides
Glass
All of these
Trepanning is performed for
Finishing a drilled hole
Producing a large hole without drilling
Truing a hole for alignment
Enlarging a drilled hole
The top and sides of the table of a shaper usually have
L-type slots
T-type slots
I-type slots
Any one of these
A bottoming tap has
Its end tapered for about three or four threads
Its end tapered for about eight or ten threads
Full threads for the whole of its length
None of the above
Chip breakers are used to
Increase tool life
Remove chips from bed
Break the chips into short segments
To minimise heat generation
Small nose radius
Increases tool life
Decreases tool life
Produces chipping and decreases tool life
Results in excessive stress concentration and greater heat generation
The angle on which the strength of the tool depends is
Rake angle
Cutting angle
Clearance angle
Lip angle
The vector sum of cutting velocity and chip velocity is __________ shear velocity.
Equal to
Less than
More than
None of these
Which of the following statement is correct about EDM machining?
It can machine hardest materials.
It produces high degree of surface finish.
The tool and work are never in contact with each other.
All of these
In a shaper, the metal is removed during
Forward stroke
Return stroke
Both the forward and return strokes
Neither the forward nor the return stroke
The relation between the tool life (T) in minutes and cutting speed (V) in m/min is (where n = An exponent, which depends upon the tool and workpiece, and C = A constant)
VnT = C
VTn = C
Vn/T = C
V/Tn = C
In metal machining, the zone where the maximum heat is generated due to the plastic deformation of metal, is called
Friction zone
Work-tool contact zone
Shear zone
None of these
In determining the various forces on the chip, Merchant assumed that the
Cutting edge of the tool is sharp and it does not make any flank contact with the workpiece
Only continuous chip without built-up-edge is produced
Cutting velocity remains constant
All of the above
A set of eight form relieved milling cutters for each module is provided to enable cutting of gears of different
Materials
Types of gears
Number of teeth
Width of gears
Gear finishing operation is called
Shaping
Milling
Hobbing
Burnishing
Which of the following statement is correct as regard to up milling?
It cannot be used on old machines due to backlash between the feed screw of the table and the nut.
The chips are disposed off easily and do not interfere with the cutting.
The surface milled appears to be slightly wavy.
The coolant can be poured directly at the cutting zone where the cutting force is maximum.
Hardness of steel greatly improves with
Annealing
Cyaniding
Normalizing
Tempering
In a plain milling cutter, the portion of the gash adjacent to the cutting edge on which the chip impinges is called
Face
Fillet
Land
Lead
The usual value of the helix angle of a drill is
20°
30°
45°
60°
If a gas metal arc process uses a low arc voltage and the arc is continuously interrupted as the molten electrode metal fills up the arc gap is known as
ARC
Short ARC
ARC length
ARC blow
Larger end cutting edge angle _________ tool life.
Increases
Decreases
Does not effect
None of these
The high cutting speed and large rake angle of the tool will result in the formation of
Continuous chips
Discontinuous chip
Continuous chips with built up edge
None of these
The main purpose of spheroidising treatment is to improve
Hardenability of low carbon steels
Machinability of low carbon steels
Hardenability of high carbon steels
Machinability of high carbon steels
Segmental chips are formed during machining
Mild steel
Cast iron
High speed steel
High carbon steel
The broaching operation in which either the work or the tool moves across the other, is known as
Pull broaching
Push broaching
Surface broaching
Continuous broaching
Gears can be best produced on mass production by
Shaping
Casting
Forming
Hobbing
Work speed of circular electrode of 220 mm diameter for carrying out seam welding at 4 welds per cm on 1.6 mm thick mild steel tube. Welding cycle consists of 3 cycles on and 2 cycles off Power supply is at 50 Hz. Calculate R.P.M. and energy requirement of the above circular electrodes assuming effective resistance between electrodes as 100 ohm.
2.17 rpm, 600 joules
6.8 rpm, 6 joules
5.03 rpm, 600 joules
22 rpm, 600 joules
In ultrasonic machining, the metal is removed by
Using abrasive slurry between the tool and work
Direct contact of tool with the work
Maintaining an electrolyte between the work and tool in a very small gap between the two
Erosion caused by rapidly recurring spark discharges between the tool and work
Side rake angle of a single point cutting tool is the angle
By which the face of the tool is inclined towards back
By which the face of the tool is inclined sideways
Between the surface of the flank immediately below the point and a plane at right angles to the centre line of the point of the tool
Between the surface of the flank immediately below the point and a line drawn from the point perpendicular to the base