MET 245
A workpiece with initial diameter of 1.5 inch is turned with depth of cut 0.075 inches. What is its machined diameter (after turning)? Do not enter the unit, only the magnitude.
1.35
A manufacturing engineer plans a turning operation. For the workpiece material and planned depth of cut of 0.05 inches, recommended cutting speed is 250 fpm and feed rate 0.01 ipr. Calculate approximate material removal rate (in3/min). Do not enter the unit, just the magnitude.
1.5
A workpiece has a hole with diameter of 1.5 inch. That hole is bored with depth of cut 0.075 inches. What is its diameter after boring? Do not enter the unit, only the magnitude.
1.65
Which point angle is the most optimal for drilling relatively hard materials, e.g. alloyed steels and cast irons? Between 118° and 90° 118° 90° 60° 135°
135°
Recommended surface speed for machining of a certain material is V = 200 fpm, and it will be machined on a lathe that has some of available spindle speeds (Ns) given below. What spindle speed you would use for a workpiece with the 3" diameter? Choose the closest value: 125 rpm 250 rpm 375 rpm 625 rpm
250 rpm
How much of energy invested in machining of certain material goes on generated heat? Up to 80% 90% and more Varies, but usually less than 25% goes on heat Between 50 and 75% Generally less than 50%
90% and more
Study the rule of 10 (or 10% rule) on page 1010 in DeGarmo and slides 25 to 30 in lecture notes "MET245_lec02_inspection_msmt." Among the choices given below, choose all instruments capable of measuring a dimension and tolerance of 1.275 (sub)0 (super)+0.012 inches: A caliper with the resolution of 0.0005 inches A caliper with the resolution of 0.001 inch A 1-2 inch micrometer with the resolution of 0.0001 inches A height gage with the resolution of 0.0005 inches A 1-2 inch micrometer with the resolution of 0.001 inch
A caliper with the resolution of 0.0005 inches A 1-2 inch micrometer with the resolution of 0.0001 inches A height gage with the resolution of 0.0005 inches
Hot hardness is: There is no specific definition of hot hardness, only hardness is defined Hardness at a certain temperature Expressed as a single number: hardness at the standard testing temperature A function (e.g. a graph or a chart) that shows variation of hardness with temperature % of hardness drop at 50% of melting temperature
A function (e.g. a graph or a chart) that shows variation of hardness with temperature
What is the margin in drills? A portion of land with full drill diameter The space created by the flutes A portion of land with reduced diameter The length of cutting edges (lips) Width of the web between the flutes
A portion of land with full drill diameter
A regular household vacuum cleaner is an example of what level of automation (as per "yardstick of automation" in DeGarmo)? A(4) A(5) A(1) A(3) A(2)
A(1)
What is the difference between A(3) and A(4) level of automation (as defined in DeGarmo)? A(4) is reserved mainly for processing industry The size of the automated system The number of sensors A(3) has open loop, and A(4) closed loop control
A(3) has open loop, and A(4) closed loop control
Machinability can be determined based on: Tool life curves: longer tool life for the given cutting speed indicates better machinability The cutting forces generated during the machining experiment All quantities mentioned here can serve as a measure of machinability of certain material Tool life curves: higher cutting speed for the given tool life indicates better machinability
ALL THE ABOVE
Processes that use free abrasive particles are (select all that apply; the score is right minus wrong answers ): Abrasive jet cutting Ultrasonic machining Abrasive waterjet cutting
Abrasive jet cutting Ultrasonic machining Abrasive waterjet cutting
Select all that apply. Workholding device should be designed in such a way so the resultant clamping force: Acts in the direction of the resultant cutting force Provide easy chip removal Act towards the fixed portion of the workholding device Does not deform the workpiece Is not distant from resultant cutting force
Acts in the direction of the resultant cutting force Provide easy chip removal Act towards the fixed portion of the workholding device Does not deform the workpiece Is not distant from resultant cutting force
Adaptive control is different from a closed loop control in a sense that: Adaptive control is easier to reprogram for different schedules Adaptive control is able to change its behavior depending on changes in the system under control Adaptive control has more feedback loops There is no significant difference Adaptive control can be used for wider variety of applications
Adaptive control is able to change its behavior depending on changes in the system under control
What is the purpose of specialized drill tips? Reduced drill "walking" Reduced thrust force Reduced burrs All of the above None of the above
All of the above
What is considered when choosing appropriate tool material? Geometry, tolerances, and surface finish Machining parameters only Machine tool, coolant used, and production rate Material of the workpiece All of the choices given here should be considered
All of the choices given here should be considered
What are common reasons for sampling inspection rather than 100% inspection/testing? If the manufacturing process is reliable If testing is destructive If inspection/testing takes a lot of time If inspection/testing is expensive All reasons mentioned here apply
All reasons mentioned here apply
What is the contemporary/lean/Taguchi's approach to quality? There is no loss as long as the process stays within the specified limits There is no loss as long as the process stays within the control limits Any deviation from the exact target value induces some loss All three above: a), b), c) None listed here
Any deviation from the exact target value induces some loss
How does Taguchi approach differ from the standard statistical experimental methods? a) Taguchi approach is not statistical b) Taguchi approach is designed for cost-effective, lean experiments in an industrial environment. Classic experiments are usually designed with more experimental runs c) Taguchi method disregards interaction between two factors. Classic statistical experiments usually are not so minimalistic d) Both b and c e) There is no difference
Both b and c
Two machines make the same product and the dimension of interest is 1.500 ± 0.03 inches. Based on the measurements done for the control chart, parts made on machine A had diameter 1.508 inches (mean value) and the standard deviation 0.017 in, while the average diameter made on machine B is 1.512 inch with standard deviation 0.012 inch. Select all statements, or a statement, that hold(s) in this situation (there can be one, or more than one choice): Machine B is more accurate Machine A is more precise Machine B is more precise Machine A is more accurate Both machines have the same precision and accuracy
Both/Either Machine B is more precise Machine A is more accurate
Which machining operations are capable of making rectangle-shaped keyways with sharp corners in the hubs (holes)? Broaching Shaping Milling Turning Boring
Broaching Shaping
Unlike pull broaches, push broaches can be susceptible to what? Buckling Velocity at the end of cut Alignment Chipping Both types of broaches are equally sensitive to loading conditions
Buckling
The shape of broached holes: Can have complex 2D shape perpendicular to the broaching direction, but has to be straight in the broaching direction (have constant width along the length) Holes are not broached Is not limited in any direction, i.e. it can have complex 2D shape and the width of the hole can vary along its length Can have only several basic shapes (circle, square, and rectangle) Can be circular only
Can have complex 2D shape perpendicular to the broaching direction, but has to be straight in the broaching direction (have constant width along the length)
Which one of these cutters can plunge straight down in the workpiece ("drill a hole")? Face mill Center cutting end mill Form milling cutter Plain cutter Non-center cutting edge mill
Center cutting end mill
A long workpiece, with the length-to-dimeter ratio that exceeds factor 10, is to be machined. Which workholding should provide the lowest deflection? Solid center with a dog and a dog plate on the spindle, a live center in the tailstock Chuck on the spindle, a live center in the tailstock, and a follower rest Mandrel Faceplate Collet in the spindle and a live center in the tailstock
Chuck on the spindle, a live center in the tailstock, and a follower rest
Which method of workholding on the spindle is expected to provide the smallest runout? Live center with dog Live center Faceplate Three-jaw chuck Collet
Collet
Recall the Cincinnati horizontal mill (arbor mill) you used in lab to make one bevel face on the hammer head. What type of construction is that machine? Fixed-bed type Planner-type Ram type Column-and-knee with vertical spindle Column-and-knee with horizontal spindle
Column-and-knee with horizontal spindle
As long as mechanical strength is concerned (and in general), it is beneficial if the surface has what residual stresses: Compressive The sign of residual stresses is not important No residual stresses Tensile
Compressive
What is/are basic function/s of cutting fluids (coolants)?
Cooling, lubrication, and chip removal
What is the difference between Cp and Cpk process capability indices?
Cp describes short-term capability of a process, when the distribution of the process outcome is perfectly centered between the specified limits. In a long run, every process drifts away from that perfect center, and how much the process drifts away is described by Cpk, the long-term process capability.
Which are the requirements for a process to be six sigma capable in terms of the process capability indices? Cp ≥ 2, Cpk ≥ 1.5 Cp ≥ 1.5, Cpk ≥ 1.5 Cp ≥ 1.33, Cpk ≥ 1.33 Cp ≥ 2, Cpk ≥ 1.33 Cpk ≥ Cp ≥ 2.0
Cp ≥ 2, Cpk ≥ 1.5
For machining of steels with high hardness (hard turning/hard milling), superalloys, and other hard-to-machine materials, especially with high removal rates, the following choice of material is the most optimal: High speed steel Cubic boron nitride (cBN) Ceramics Carbide
Cubic boron nitride (cBN) Ceramics
One of the major problems in the coating processes that use voltage applied to the workpiece (electroplating, physical and chemical vapor depositions) is: There are no problems with these processes Overheating Electric current damages the workpiece properties Current density may not be uniform across the workpiece, being largest at corners and protrusions
Current density may not be uniform across the workpiece, being largest at corners and protrusions
Check all that is associated with the climb milling: Cutter pulls on the workpiece in the feed direction Up milling Cutter enters the cut with minimal chip thickness Cutter pulls on the workpiece opposite to the feed direction Cutter enters the cut with maximum chip thickness Down milling
Cutter pulls on the workpiece in the feed direction Cutter enters the cut with maximum chip thickness Down milling
How abrasive grits interact with machined surfaces? Select all correct answers (the score is right minus wrong answers ): Cutting action Plowing action (significantly reduced cutting action) Rubbing action (no, or almost no cutting)
Cutting action Plowing action (significantly reduced cutting action) Rubbing action (no, or almost no cutting)
Which statement best describes the tool length offset: Some safe distance from the workpiece where tools can move in rapid mode (fastest possible) Dimensions of the workpiece Defines the distance between the tool tip and workpiece Distance in X, Y, Z directions from the machine coordinate system to some chosen point on the workpiece
Defines the distance between the tool tip and workpiece
The basic machining parameters are: Depth of cut, feed rate, cutting speed Power, cutting speed, depth of cut Cutting speed, feed rate, cutting force Machining time, material removal rate, depth of cut
Depth of cut, feed rate, cutting speed
Which material offers potentially longest tool life in machining plastics and non-ferrous alloys (aluminum)? High speed steel Carbide Ceramics Cubic boron nitride Diamond
Diamond
Which tool material should NOT be used for machining of cast irons? Carbide Diamond Ceramics High speed steel Cubic boron nitride
Diamond
What type of liquids are used in electrochemical machining (ECM) and electrical discharge machining (EDM)? Question options: They use neither dielectric nor electrolytic fluids Both processes use dielectrics and electrolytes, depending on the application Dielectric fluids are used for EDM, electrolytes for ECM Dielectric fluids are used for ECM, electrolytes for EDM
Dielectric fluids are used for EDM, electrolytes for ECM
Select main paint application processes: Dipping Spraying Electrostatic deposition Electrodeposition Powder deposition
Dipping Spraying Electrostatic deposition Electrodeposition Powder deposition
Two basic types of manufacturing are [x] and [y] manufacturing. (Some example products for one type of manufacturing: gear, car, pencils, TV...; examples for the other type: beverage, cookie, shampoo, fuel...) Processing and assembly Types I, II, and III of manufacturing Manufacturing and processing industries Project and flow Discrete and continuous
Discrete and continuous
What is called a part zero, or a work zero, or a part reference zero PRZ (different names for the same thing)? Distance in X, Y, Z directions from the machine reference point (MRZ) to some point on the workpiece that is chosen to be the reference point Defines the distance between the tool and workpiece (chose point on it, usually the highest point) Dimensions of the workpiece Some safe distance from the workpiece where tools can move in rapid mode (fastest possible)
Distance in X, Y, Z directions from the machine reference point (MRZ) to some point on the workpiece that is chosen to be the reference point
A workpiece is fixed in the lathe between two live centers, one center being in the spindle and another in the tailstock quill. What is used in this situation to transfer the torque from the spindle to the workpiece? Faceplate Collet Dog with a dogplate Mandrel Chuck
Dog with a dogplate
Which type of these milling cutter geometries produces the lowest cutting forces (combination of the radial and axial rake angles; refer to the lecture slides)? Double positive Positive-negative Cutting forces are similar regardless of the cutter type Those types of cutters do not exist Double negative
Double positive
A process that removes the outer layer of the grinding wheel that has worn out grit and is clogged with swarf (chips), and exposes fresh grit with sharper edges, is called: Wheel sharpening Reshaping Forming Dressing
Dressing
Machines specialized for drilling are called how? Drill presses Machine centers Boring machines There are no machines specialized for drilling Customized milling machines
Drill presses
Final dimensions of machined features are not the same as dimensions of the tool (or mask) in the following process/processes (select all that apply): Question options: Electrical discharge machining (EDM) Photochemical machining (PCM) Electrochemical machining (ECM)
Electrical discharge machining (EDM) Photochemical machining (PCM) Electrochemical machining (ECM)
Choose the most versatile milling cutter from the list below. It can do both bottom/face milling and side/peripheral milling, and is often chosen for all sorts of machining, although there might be better and more productive options in a given situation. Plain helical-tooth milling cutter End milling cutter Form milling cutters Face milling cutter Woodruff style cutters
End milling cutter
If a machine cannot make parts that meet specifications (USL and LSL), what can be done to improve this situation: Do a 100% inspection to separate good from bad parts and rework parts that can be corrected Everything mentioned here Shift production to a different (better) machine, i.e. decrease standard deviation σ Perform controlled experiments to determine the main sources of variation and try to solve them Ask the customer to relax the specified limits, i.e. make the (USL - LSL) difference larger
Everything mentioned here
Which cutters are the most suitable for producing large flat surfaces? Select all that apply. End milling cutter Woodruff style cutters Face milling cutter Plain helical-tooth milling cutter Form milling cutters
Face milling cutter Plain helical-tooth milling cutter
You have become a (big) manager and want to start improving manufacturing processes you are in control of. The first step you want to make is to receive an input from each employee about what they think are the root causes of problems at their work place. You will give them to fill out which form/chart? Scatter diagrams Pareto charts Run charts Fishbone (cause-and-effect) diagrams Control charts
Fishbone (cause-and-effect) diagrams
What is the difference between jigs and fixtures? Mainly the complexity of the device There is no principal difference Fixtures are part of a machine, while jigs are separate mechanisms Fixtures provide only holding, while jigs provide both precise location and holding
Fixtures provide only holding, while jigs provide both precise location and holding
The interim cell is a term used: For a mixed layout For any cell with the function to supply cells associated with it For a layout obtained by relocating existing machines into a cell For a cell that is between subassembly cell and assembly line, and serves both of them or only the main assembly line This term does not exist
For a layout obtained by relocating existing machines into a cell
Which two commands have the proper format to call a clockwise circular motion of a tool? G02 X1.2 Y.2 I.5 J-.5 G02 X1.2 Y.2 R2. G01 X1.2 Y.2 G03 X1.2 Y.2 R2. G03 X1.2 Y.2 I.5 J-.5
G02 X1.2 Y.2 I.5 J-.5 G02 X1.2 Y.2 R2.
Select materials that are used for EDM electrodes: Question options: Graphite Copper and coper-based alloys (brass) Tungsten, copper-tungsten, sometimes silver-tungsten Tool steels (high-speed steels) Aluminum and high-conductive aluminum alloys
Graphite Copper and coper-based alloys (brass) Tungsten, copper-tungsten, sometimes silver-tungsten
Select all that can be considered as an end effector in robots: Gripper Welding torch Waterjet cutting head Painting gun A spindle with cutting tool
Gripper Welding torch Waterjet cutting head Painting gun A spindle with cutting tool
The volume between teeth in saws and broaches is called: Flute Relief Kerf Pitch Gullet
Gullet
Which types of drills are known as deep-hole drills? BTA drills and Bickfort drills Jobber drills Center core drills Bickfort and Racon drills Gundrills and BTA drills
Gundrills and BTA drills
What are the basic types of saw blades? Select all that apply: Hacksaw Bandsaw Contour saw Vertical saw Circular saw
Hacksaw Bandsaw Circular saw
In Taguchi's experiments, what is used as a criterion to decide whether or not an input parameter has a strong influence on the output? Higher statistical significance Higher signal-to-noise ratio Higher levels of factors Higher levels of variables None listed here
Higher signal-to-noise ratio
A process used for surface finishing of engine cylinders is: Creep grinding Lapping Internal centerless grinding Honing Superfinishing
Honing
Select all that apply. A manufacturing system consists of: Human workers Material handling system Hardware (tools, machines...) and computer systems that control them
Human workers Material handling system Hardware (tools, machines...) and computer systems that control them
In industrial setup (not in a do-it-yourself makeshift setup in a garage shop), broaching operation is performed: In a single pass, by moving the broach past the workpiece, or vice versa, moving the workpiece past the broach In several reciprocal motions of the workpiece In several reciprocal motions of the broach With rotation of the broach and translation of the workpiece With a combination of rotation and linear motion of the tool (broach)
In a single pass, by moving the broach past the workpiece, or vice versa, moving the workpiece past the broach
In manufacturing cells, 100% quality control is the most efficiently performed if parts are inspected: No measurement is performed in reliable cells In the center of the cell In a separate cell for QC In decouplers
In decouplers
The difference between shaping and planing is that:
In shapers, the tool does reciprocal motion to make the cut and return back, and then the workpiece makes stepover for the next cut (the workpiece is fed perpendicularly to the cutting motion for the next cut). In planers, the workpiece makes reciprocal motion while the tool is stationary, and then the tool is fed perpendicularly to the cutting motion for the next cut (the tool makes stepover motion)
How does variation in the measuring device (instrument) effect the measurements obtained on a component? It will make measured dimension appear smaller Usually makes no difference, but may depend from case to case It does not make any difference It increases observed variation in the component It will make measured dimension appear larger
It increases observed variation in the component
What is usual value of the rake angle of grits in grinding wheels? Highly positive It depends on the wheel diameter and depth of cut Zero Highly negative It is very random, from positive to negative angles, and varies from grit to grit
It is very random, from positive to negative angles, and varies from grit to grit
A maintenance department in some company makes all kinds of parts on occasional basis. The most optimal layout would be: Flow shop (flow-line layout or product layout) It can be in any of them Cellular layout Job shop (process layout) Project shop (fixed position layout)
Job shop (process layout)
Consider how schools/colleges and departments in the Purdue University are organized. What manufacturing system layout it would belong to? Project shop (fixed position layout) Cellular layout Job shop (process layout) A mixture of all the layouts listed here Flow shop (flow-line layout or product layout)
Job shop (process layout)
Is it better to have higher or lower etch factor? Question options: That factor is not important That factor does not exist Lower etch factor is better Higher etch factor is better
Lower etch factor is better
A belt pulley is cast and needs machining (search the Internet if you do not know how it looks like). The hub has draft angles (slightly conical shape), and is short, which makes it is very inconvenient for holding. The hole is already machined. The next operation is turning of the rim which will be in contact with the belt. The outside surface should be concentric with the hole, as well as smooth and continuous, without any marks. What workholding would be best suited to fix this pulley on the lathe? Faceplate Collet Mandrel Chuck Chuck with a live center
Mandrel
Select all that apply (score = correct - incorrect answers). Faster changeover (machine setups between different parts) is enabled with: Master jigs Universal jigs Intermediate jigs Dedicated jigs
Master jigs Intermediate jigs
From the choices given below, which combination can be used to determine power necessary for a machining operation? Material removal rate and cutting speed Cutting force and machining time Material removal rate and unit power (power rating) for the workpiece material Volume machined and cutting speed Material removal rate and machining time
Material removal rate and unit power (power rating) for the workpiece material
Fixtures made by combining various standard elements, which can be unassembled and used to make other fixtures, are called: Intermediate fixtures Assembly fixtures Universal fixtures Dedicated fixtures Modular fixtures
Modular fixtures
The specified limits are defined with its upper and lower limits USL and LSL, respectfully. Likewise, the control limits are defined with UCL LCL. Are USL/LSL and UCL/LCL related? Yes, they influence each other No It depends on the quality policies in a company USL/LSL dictate UCL/LCL UCL/LCL dictate USL/LSL
No
What can serve as a sign that the tool needs to be changed with a new one? Check all that apply: Overheated chip, most easily recognized by the change in chip color Worsened surface finish Increased cutting force or power consumed by the machine tool Predefined cutting time (or the number of parts machined) Tool wear (e.g. the length of flank wear)
Overheated chip, most easily recognized by the change in chip color Worsened surface finish Increased cutting force or power consumed by the machine tool Predefined cutting time (or the number of parts machined) Tool wear (e.g. the length of flank wear)
You have located some problems in production and now you want to tackle them. The most natural decision is to start from the biggest problems because they will give the biggest savings (low-hanging fruit). You will identify the biggest problems by using: Run charts Pareto charts Scatter diagrams Fishbone (cause-and-effect) diagrams Control charts
Pareto charts
Select the three basic types of automation: Programmable Flexible Closed-loop Adaptive Fixed Open-loop
Programmable Flexible Fixed
Select all machines/equipment that belong to programmable automation: Programmable logic controllers Relays Transfer lines Robots Computer numeric control machines
Programmable logic controllers Robots Computer numeric control machines
What is used to decrease the pull (or push) force in broaches and/or help easier chip breaking? Select all that apply: Nothing listed here decreases the push (pull) force Progressive teeth design for flat broaches Rotor or jump teeth Push/pull force cannot be reduced in broaches Notched teeth
Progressive teeth design for flat broaches Rotor or jump teeth Notched teeth
Select all that apply. Helical-tooth plain cutters, in comparison with straight-tooth plain cutters: Increase chatter because cutting edge enters the cut under some angle Provide gradual entrance of cutting edge in workpiece material Reduce cutting force Increase cutting force but provide better surface finish Reduce chatter
Provide gradual entrance of cutting edge in workpiece material Reduce cutting force Reduce chatter
These the basic principles included in a good design of experiments (select all that apply): Accuracy of measurements Randomization Analysis of variance Replication Blocking
Randomization Replication Blocking
Which tool is the best choice to bring the hole diameter to a more accurate dimension and improve surface finish? Reamers Center core drills Counterbores Spade drills Subland drills
Reamers
What is the ultimate goal of six sigma approach to the product quality? Reduce variability of the process so the scrap rate is at levels as low as 3.4 per million Develop standardized procedures for all processes in a company (DMAIC, DMADV...) Influence suppliers to increase quality of their products in increments of 3.4% Decrease the probability of failure to 3.4% Implement Taguchi method of quality control
Reduce variability of the process so the scrap rate is at levels as low as 3.4 per million
What is the G ratio in grinding? Removal rate of machined material relative to the removal rate of the grinding wheel Volume ratio of bonding material to grits Centrifugal acceleration a wheel can endure without shattering Surface ratio of bonding material to grits
Removal rate of machined material relative to the removal rate of the grinding wheel
Check all that apply. Beside the magnitude and direction of the clamping force, some things to consider when designing a jig or fixture are: Repeatability of positioning Safety Ruggedness Variations in dimensions and shape of workpieces Ergonomics
Repeatability of positioning Safety Ruggedness Variations in dimensions and shape of workpieces Ergonomics
Which of these methods produces holes with the straightest walls, and is capable of achieving highest aspect ratios? Question options: Shaped tube electrolytic machining (STEM) Electrostream machining/drilling (ESM) Electrochemical machining/drilling (ECM)
Shaped tube electrolytic machining (STEM)
Imagine two manufacturing processes (machines) which make the same part, one being four sigma capable and the other one six sigma capable. You compare their control charts and the following holds for their control limits: Six sigma capable process have narrower range of control limits (UCL - LCL) Four sigma capable process have narrower range of control limits (UCL - LCL) UCL - LCL depends more on what is the process average in particular case than on the process capability More information is needed to guess what is the difference in control limits between these two processes
Six sigma capable process have narrower range of control limits (UCL - LCL)
What types of helix angles exist in twist drills? 60°, 90°, 118°, and 135° Helix angles are not specified 45° and 60°, relative to the drill axis There is only one, 45° standard helix angle Slow, regular, and fast helix
Slow, regular, and fast helix
Which component of lathes provides motion to the workpiece? Carriage Quill Cross slide Tailstock Spindle
Spindle
Which part of milling machines provides the cutting speed? Knee Leadscrew Table Spindle Carriage
Spindle
Which tool is used to prevent or minimize drill walking? Select all that apply. Spot drills Drills with specialized point geometry Center punches Reamers Counterbores
Spot drills Drills with specialized point geometry Center punches
What is the most important advantage of a "real" statistical design of experiments over "engineering," or classic, DOE? Statistical DOE requires less calculation Engineering DOE requires highly specialized expertise Statistical DOE can find interactions between influencing factors, while "engineering" DOE usually cannot Principles of statistical DOE can be applied to any discipline, not only engineering Statistical DOE requires smaller sample size and/or smaller number of experimental runs
Statistical DOE can find interactions between influencing factors, while "engineering" DOE usually cannot
In general, nontraditional machining (NTM) technologies have these advantages over traditional machining (select all that apply): Question options: Surface finish of machined features is better. Dimensional accuracy of machined parts is better. Materials that are otherwise difficult to machine do not represent special difficulty for NTM processes. Residual stresses are smaller or absent. It is possible to drill holes with extremely small diameter and very high depth-to-diameter aspect ratio.
Surface finish of machined features is better. Dimensional accuracy of machined parts is better. Materials that are otherwise difficult to machine do not represent special difficulty for NTM processes. Residual stresses are smaller or absent. It is possible to drill holes with extremely small diameter and very high depth-to-diameter aspect ratio.
Which command instructs the machine to put tool #10 in the spindle? G43 H10 T10 M05 T10 M06 G41 D10 T10 M03
T10 M06
Some robots have sensitive load cells in their grippers in order to handle fragile and/or very small parts. What group of sensors is that?
Tactile
Select all answer choices that are true for centerless grinding (the score is right minus wrong answers): The axial feed rate is controlled by the regulating wheel Plain flat surfaces can be ground Setup of workpieces is simple and can easily be automated The workpiece is not held in the spindle or between centers It is used mostly for straight cylindrical parts without any geometric features (one diameter, no keyseats, holes, or any other features) Long workpieces can be distorted
The axial feed rate is controlled by the regulating wheel Setup of workpieces is simple and can easily be automated The workpiece is not held in the spindle or between centers It is used mostly for straight cylindrical parts without any geometric features (one diameter, no keyseats, holes, or any other features)
Compare the cycle time of a manufacturing cell and the cycle time of individual machines within that cell. In what relation these two times should be: These times are not important because manufacturing cells are flexible The cycle time of the cell should be longer Equal, or roughly equal The cycle time of individual machines should be longer These times are controlled by the manufacturing operations and cannot be related
The cycle time of the cell should be longer
Select all that apply. As the rake angle decreases: The depth of the deformed (damaged) layer increases Residual stresses become less tensile and may become compressive The depth of the deformed (damaged) layer decreases Residual stresses get less compressive and may become tensile It makes no much difference on the properties of machined surface
The depth of the deformed (damaged) layer increases Residual stresses become less tensile and may become compressive
The 3-2-1 principle of workholding is: The condition that must be exactly satisfied; less support as well as any additional support decrease the level of constraint The minimum condition for successful constraining of the workpiece The list of steps for fixing the part The maximum condition for successful constraining of the workpiece Not related to workholding
The minimum condition for successful constraining of the workpiece
What is considered as the maximal rotational speed for chucks? The one at which the chuck loses two thirds of its initial gripping force (still has one third of its initial gripping force when the spindle is not turning) Larger than the maximal speed of the machine The one at which chatter starts to be more intense The one at which the chuck loses its grip It is not specified
The one at which the chuck loses two thirds of its initial gripping force (still has one third of its initial gripping force when the spindle is not turning)
What defines the grade of a grinding wheel? Application range The quality class of materials used to make the wheel Spacing between the grits The strength (hardness) of a wheel - how strongly the grits are held in the wheel
The strength (hardness) of a wheel - how strongly the grits are held in the wheel
What is called a tooth set in saws? Orientation of the blade (teeth): vertical, horizontal, angled The method of varying the pitch of the blade teeth (the teeth spacing) The shape of the cutting teeth (their profile) The way in which the teeth are offset from the centerline in order to make the cut be wider than the gage thickness (thickness of the back side of the saw blade). Tooth sets prevent unnecessary rubbing of the whole blade against the cut surfaces
The way in which the teeth are offset from the centerline in order to make the cut be wider than the gage thickness (thickness of the back side of the saw blade). Tooth sets prevent unnecessary rubbing of the whole blade against the cut surfaces
Electric discharge machining (EDM) belongs to which of the following basic groups of nontraditional processes? Question options: Electrochemical NTM Thermal NTM Mechanical NTM Chemical NTM
Thermal NTM
Which contaminants should be removed from coolants when they are recycled? a) Hard particles (chips etc.) b) Entrapped fluids c) Bacteria, fungi, and mold These three: a), b), and c)
These three: a), b), and c)
The following statements hold for burrs (check all that apply): They are larger on locations where the tool exits the workpiece then on the tool entrance locations Looking relative to the primary tool cutting motion, they are larger in the forward motion of the tool than in other directions They can be decreased with appropriate machining strategy (where the tool enters and exits the cut and the toolpath on the workpiece) They are minimized if tools exits at locations with previously machined undercuts and grooves Their appearance depends only on the workpiece material, not machining strategy
They are larger on locations where the tool exits the workpiece then on the tool entrance locations Looking relative to the primary tool cutting motion, they are larger in the forward motion of the tool than in other directions They can be decreased with appropriate machining strategy (where the tool enters and exits the cut and the toolpath on the workpiece) They are minimized if tools exits at locations with previously machined undercuts and grooves
What makes flexible manufacturing systems be called flexible? Different sequence of operations can be used to make the same workpiece Machines can be very easily rearranged to a different layout They can make limited number of different parts (a part family) in any order, i.e. no special scheduling is needed Both number and arrangement of machines are easily modified They can make a wide variety of parts
They can make limited number of different parts (a part family) in any order, i.e. no special scheduling is needed
End mills with wavy flute are recommended for heavy rouging of pockets and slots (hogging). This waviness can be relatively intense (serrated/corncob flute), medium (sinusoidal flute), or milder (variable helix). Select all characteristics that apply to this type of cutters: They decrease chatter due to smaller cutting forces (chip thinning, gradual entry, and reduced contact length between the cutting edge and workpiece) They produce rough surface, so for better surface quality a finishing cut is needed with a cutter that has straight flute edge Wavy flute edge serves mainly to improve surface finish Wavy flutes enhance chip breakage Wavy flute produces longer curly chips that are easier to remove from the cutting zone
They decrease chatter due to smaller cutting forces (chip thinning, gradual entry, and reduced contact length between the cutting edge and workpiece) They produce rough surface, so for better surface quality a finishing cut is needed with a cutter that has straight flute edge Wavy flutes enhance chip breakage
Select the statements that hold for redundant locators (score = correct - incorrect answers): They have no useful purpose They provide needed stability to the workpiece They do not add additional restriction to the degrees of freedom They are a consequence of bad jig design
They provide needed stability to the workpiece They do not add additional restriction to the degrees of freedom
From the ceramic coating listed below, the most frequent/popular coating for cutting tools is: TiCN Al2O3 TiN TiAlN PCD (FOR SURE NOT THIS) cBN
TiCN Al2O3 TiN TiAlN
What is the difference between the evaluation length and the cutoff length in surface roughness measurements? Cutoff length is usually larger They are same Evaluation length is usually larger
To estimate roughness from measuring the height of "hills and valleys" of the surface profile at distances shorter than the cutoff length. Waviness is evaluated from irregularities that are spaced at distances larger than that cutoff length
Under normal working conditions with predominant flank wear, i.e. with no premature and catastrophic tool failure, the most harmful to tool life would be: To increase the cutting speed To increase the feed rate To increase the depth of cut All three have similar effect on the tool life It depends from case to case
To increase the cutting speed
With G00, the machine tool is instructed to do what? To move the tool to commanded point with a circular motion in the counter-clockwise direction To move the tool to commanded point with a circular motion in the clockwise direction To move the tool to commended point in a single straight line To move the tool to commanded point as fast as possible
To move the tool to commanded point as fast as possible
With G02, the machine tool is instructed to do what? To move the tool to commanded point as fast as possible To move the tool to commended point in a single straight line To move the tool to commanded point with a circular motion in the clockwise direction To move the tool to commanded point with a circular motion in the counter-clockwise direction
To move the tool to commanded point with a circular motion in the clockwise direction
With G03, the machine tool is instructed to do what? To move the tool to commended point in a single straight line To move the tool to commanded point as fast as possible To move the tool to commanded point with a circular motion in the clockwise direction To move the tool to commanded point with a circular motion in the counter-clockwise direction
To move the tool to commanded point with a circular motion in the counter-clockwise direction
With G01, the machine tool is instructed to do what? To move the tool to commanded point as fast as possible To move the tool to commanded point with a circular motion in the counter-clockwise direction To move the tool to commended point in a single straight line To move the tool to commanded point with a circular motion in the clockwise direction
To move the tool to commended point in a single straight line
Select all that apply (score = correct - incorrect answers). Faster clamping and unclamping of the same type of workpieces is enabled with: Mold clamps Toggle clamps Cam latches Universal strap clamps Power actuated clamps
Toggle clamps Cam latches Power actuated clamps
A manufacturing cell in which workers can help each other, but only in the neighboring cells (they do not cross the aisle) is called: A single-man cell design Subcell design Toyota sewing system cell design A rabbit chase cell design Any of the given cell designs has this property
Toyota sewing system cell design
Which of the listed lathes are designed to normally hold more than one tool? Speed lathe Engine lathe Turret lathe Toolroom lathe Automatic (Swiss screw) lathe
Turret lathe Automatic (Swiss screw) lathe
Select main types of motion of robotic joints: Twisting Orthogonal Revolving Linear Rotational
Twisting Orthogonal Revolving Linear Rotational
Which error can (most frequently) lead to legal action from the customer for a defective product that caused bodily injury? Errors in setting up proper manufacturing parameters Type II sampling error (β error) Design errors Type I sampling error (α error)
Type II sampling error (β error)
Before black oxiding, the following finishing process was used for the hammer heads you made in lab for the Project 2: Wire brushing Belt sanding Vibratory finishing Chemical solvent cleaning (acetone/alcohol) Blast cleaning
Vibratory finishing
Rake face is a surface: Which is separated from the machined surface by a small relief angle Which is in contact with the chip that is sliding against it Which is separated from the unmachined surface by a small relief angle
Which is in contact with the chip that is sliding against it
Select two statements that apply to G90 and G91 commands. With G90, all coordinates in the program are related to the program zero With G90, all coordinates in the program are related to the current tool location With G91, all coordinates in the program are related to the program zero With G91, all coordinates in the program are related to the current tool location G91 sets the length units to millimeters G90 sets the length units to inches
With G90, all coordinates in the program are related to the program zero With G91, all coordinates in the program are related to the current tool location
Is there a work-in-progress in a factory with the lean cellular manufacturing? Yes, but it is kept at minimum It depends on the type of the cell (some have, some do not) No, lean manufacturing is known for no WIP Yes, in similar amount as in any other type of the manufacturing system
Yes, but it is kept at minimum
Ra, the arithmetic roughness mean (average) is the most frequently used surface roughness parameter. What do you think, is it possible that two surfaces with different Rt (Rmax, maximum roughness depth) have the same value of Ra?
Yes, it is very likely
