What are database cardinalities? Give some examples of cardinalities for an accounting
application other than sales.
Cardinalities describe how the entities in a database are related. For example, a company where
each company laptop computer is ass
A double-acting hydraulic cylinder is used to actuate a linear joint of an industrial robot. The inside diameter of
the cylinder is 3.5 in. The piston rod has a diameter of 0.5 in. The hydraulic power source can generate up
to 500 lb/in of pressure at
What is an optical encoder, and how does it work?
An optical encoder is a device for measuring rotational speed that consists of a light source and a
photodetector on either side of a disk. The disk contains slots uniformly spaced around the
The positioning table for a component insertion machine uses a stepping motor and lead
screw mechanism. The design specifications require a table speed of 0.5 m/s and an
accuracy = 0.02 mm. The pitch of the lead screw =
6.0 mm, and the gear ratio = 2:1 (2
What are three disadvantages of implementing NC technology?
Four disadvantages are identified in the text:
(1) Higher investment cost because NC machines are more expensive than conventional machine
(2) Higher maintenance effort due to great
What is distributed numerical control (DNC)?
Answer: Distributed numerical control is a distributed computer system in which a central
computer communicates with multiple CNC machine control units. It evolved from direct
numerical control in which
What are four advantages of numerical control when properly applied in machine tool
The text lists the following 11 advantages: (1) nonproductive time is reduced, (2) greater
accuracy and repeatability, (3) lower scrap rates, (4) inspec
What is numerical control?
What are the three basic components of an NC system?
As defined in the text, numerical control (NC) is a form of programmable automation in which
the mechanical actions of a machine tool or other equipment are controlled
What are some of the machine tool types to which numerical control has been applied?
What is a machining center?
NC has been applied to nearly all machine tools types, including lathes, boring mills, drill
presses, milling machines, and cylindrical
Referring back to Problem 7.8, the mechanical inaccuracies in the open loop positioning
system can be described by a normal distribution whose standard deviation = 0.005 mm.
The range of the worktable axis is 500 mm, and there are 12 bits in the binary re
The two axes of an x-y positioning table are each driven by a stepping motor connected to a
leadscrew with a 4:1 gear reduction. The number of step angles on each stepping motor is
200. Each leadscrew has a pitch = 5.0 mm and provides an axis range = 400.
Two stepping motors are used in an open loop system to drive the lead screws for x-y
positioning. The range of each axis is 500 mm. The shafts of the motors are connected
directly to the lead screws. The pitch of each lead screw is 4.0 mm, and the number
Stepping motors are used to drive the two axes of an insertion machine used for electronic
assembly. A printed circuit board is mounted on the table which must be positioned
accurately for reliable insertion of components into the board. Range of each axi
A component insertion machine takes 2.0 sec to put a component into a printed circuit (PC)
board, once the board has been positioned under the insertion head. The x-y table that
positions the PC board uses a stepper motor directly linked to a lead screw f
A lead screw coupled directly to a dc servomotor is used to drive one of the table axes of an
NC milling machine. The lead screw has 2.5 threads/cm. The optical encoder attached to
the lead screw emits 100 pulses/rev of the lead screw. The motor rotates a
A dc servomotor drives the x-axis of a NC milling machine table. The motor is coupled
directly to the table lead screw, whose pitch = 6.25 mm. An optical encoder is connected to
the lead screw. The optical encoder emits 125 pulses per revolution. To execu
Write the part program to drill the holes in the part shown in Figure P7.26. The part is 12.0
mm thick. Cutting speed = 100 m/min and feed = 0.06 mm/rev. Use the lower left corner of
the part as the origin in the x-y axis system. Write the part program in
A NC machine tool table is powered by a servomotor, lead screw, and optical encoder. The
lead screw has a pitch = 5.0 mm and is connected to the motor shaft with a gear ratio of 8:1
(8 turns of the motor for each turn of the lead screw). The optical encod
A numerical control drill press drills four 10.0 mm diameter holes at four locations on a flat aluminum plate in a
production work cycle. Although the plate is only 12 mm thick, the drill must travel a full 20 mm vertically at
each hole location to allow
Name four of the six part characteristics that are most suited to the application of numerical
control listed in the text.
The six part characteristics identified in the text are the following:
(1) batch production,
(2) repeat orders,
(3) complex p
Although NC technology is most closely associated with machine tool applications, it has been
applied to other processes also. Name three of the six examples listed in the text.
The six non-machine tool applications listed in the text are
A double-acting hydraulic cylinder has an inside diameter = 75 mm. The piston rod has a diameter = 14 mm. The
hydraulic power source can generate up to 5.0 MPa of pressure at a flow rate of 200,000 mm /sec to
drive the piston. (a) What are the maximum p
A DC servomotor has a torque constant = 0.088 N-m/A and a voltage constant = 0.14 V/(rad/sec). The armature
resistance is 2.15 ohms. A terminal voltage of 30 V is used to operate the motor. Determine (a) the starting
torque generated by the motor just as
A voltage of 24 V is applied to a DC servomotor whose torque constant = 0.115 N-m/A and voltage constant
= 0.097 V/(rad/sec). Armature resistance = 1.9 ohms. The motor is directly coupled to a blower
shaft for an industrial process. (a) What is the stall
What are the three functions of adaptive control?
The three functions of adaptive control are the following: (1) Identification function, in which
the current value of the index of performance of the system is determined, based on
What is computer process monitoring?
What is direct digital control (DDC), and why is it no longer used in industrial process control
Answer: Computer process monitoring involves the use of the computer to observe the process
What is polling in computer process control?
What is an interlock? What are the two types of interlocks in industrial control?
Answer: In computer process control, polling refers to the periodic sampling of data that
indicates the status of the pro
In the operation of a certain production machine, one worker is required at a direct labor rate = $10/hr. Applicable
labor factory overhead rate = 50%. Capital investment in the system = $250,000, expected service life = 10
years, no salvage value at the
Mfg Metrics-3e-SI 11-24, 24/06, 06/04/07,
Costs have been compiled for a certain manufacturing company for the most recent year. The summary is shown in
the table below. The company operates two different manufacturing plants, plus a corporate he
Theoretically, any given production plant has an optimum output level. Suppose a certain production plant has annual
fixed costs FC = $2,000,000. Variable cost VC is functionally related to annual output Q in a manner that can
be described by the function