DML

1. Clearly defined and weighed objectives 2. Justified magnitude assignments 3. Use linear score assignments 4. Highest scoring concept wins

4 Key elements to decision matrices:

A. provide positive mechanical engagement B. easy removal without damaging components

Advantages of splines includes: A. provide positive mechanical engagement B. easy removal without damaging components C. can be designed to slip at a predetermined amount of torque transmission D. simple to fabricate E. all the above

rolling

All quality fastener threads are created using which of the following process?

raise lock plastic table cover

Always _____ and _____ the milling machine spindles before changing tools over the ____ _____ _____

spindle speed

Always adjust _____ _____ with the milling machines running

TRUE

Always perform shearing/punching before making bends in sheetmetal parts TRUE/FALSE

~1000 times

Based on the over-versus under-tightening examples, properly torqued fasteners can withstand how many more force application cycles before failure?

0.0625-.125 0.0625-.125 0.0625-.125

Based on your experience working in the lab estimate the typical tolerance range associated with the following manual processes: bandsaw cutting: _________ sheetmetal shearing: __________ sheetmetal bending: _______

FALSE

Before changing the lathe between HI/LOW range you must ask for TA help TRUE/FALSE

FALSE

Before changing tools in the lathe the spindle must first be raised to and locked in its upper most position TRUE/FALSE

TRUE

Before changing tools in the lathe the spindle must first be raised to and locked in its upper most position TRUE/FALSE

FALSE

CNC machines always require less time to make a part than manual machines: TRUE/ FALSE

100 100 1/2 764 .008 .008 6.1 N= 460 rpm, f= 3.7 in/min

Calculate the spindle speed (rpm) and federate [in/min] for a 1/2 inch HSS drill bit in mild steel (0.2-0.3 C) when using a manual milling machine From Table 1: V= ______ ft/min N= 12 in/ft x V ft/min (pi x D in/rev) N= 12 in/ft x ___ ft/min (pi x 1/2 in/rev) N= ____ rpm from Table 2: fr= _____ in /rev f= N rev/min x fr in/rev f= 764 rev/min x ____ in/rev= _____ in/min scale back 60% ____________, ____________

250 250 1910 .004 .004 2 15.3 N= 1150 rpm, f= 9.2 in/min

Calculate the spindle speed [rpm] and federate [in/min] used when milling an aluminum part with a. 1/2 inch diameter., 2 flute HSS end mill on a manual milling machine in lab from table 1: V= ______ ft/min N= 12 in/ft x V ft/min/ ( pi x D in/rev) N= 12 in/ft x ____ ft/min / (pi x _____ in/rev) N= ______ rpm from table 3: ft= ______ in/tooth f = N rev/min x ft in/rev x m teeth/rev f = 1910 rev/min x ______ in/tooth x _______ teeth/rev f = _______ in/min scale back 60%: ____________, ______________

desired preload and fastener diameter

Calculation of required fastener tightening torque depends on two variables:

consciously trying to design parts that can be manufactured for the lowest cost while meeting the required design intent and safety/service factors

Define what is meant by the phrase design for manufacturability or DFM:

FALSE

Dissimilar metals can be joined using the arc welding process if the proper filler metal is used: TRUE/FALSE

FALSE

Evaluation matrix objectives are weighted because not all concepts are of equal importance: TRUE/FALSE

TRUE

Every quantitative magnitude assigned in a decision matrix must be clearly justified with supporting data: TRUE/FALSE

bolts are fastened using a nut while screws are threaded directly into the material they will hold

Explain the difference between a bolt and screw:

Relay is on/off Proportional has variable speed control

Explain the difference between relay and proportional control

1. complex parts requiring multiple axes of simultaneous motion 2. mass production

Explain the two types of parts CNC machines are better suited for over manual machines

tension shear

Fastener threads should always be loaded in _______ and should never be loaded in ________.

clamp parts together

Fasteners are primarily designed to do what?

simple low quality parts

For what type of parts are manual machines a better choice than CNC machines:

output speed

Gearing can be used to increase motor torque at the expense of what?

V= pi x d x N x .6 V= pi(6)(150)(.6) V= 2.4 ft/s

Given a motor shaft speed of 150 rpm, a 6" diameter wheel and 60% efficiency, what is the linear loaded velocity of the robot? [ft/sec]

TRUE

Lathe, mill and drill press spindle speeds must be adjusted while the machines are running: TRUE/FALSE

1. omitting necessary dimensions 2. omitting tolerances for nay dim (or assigning one tolerance for all dims) 3. dimensioning to hidden lines 4. showing hidden lines or dimensions in iso views 5. shading in isometric or orthographic views 6. duplicating dimensions in multiple part views 7. dimensioning which requires the manufacturer to perform calculations to make the part 8. dimensioning a hole with regard to its radius or an arc with regard to its diameter 9. specifying metric thread callouts as UNC/UNF 10. specifying metric thread lengths in inches 11. dimensions placed carelessly over part views 12. inconsistent line weights across dimensions 13. disproportionately scaled dimensions

List 13 common dimensioning mistakes that cause us to look like we don't know what were doing:

1. designing clearance holes as line firs (i.e. specifying 0.250" instead of 0.257 or 0.266 2. specifying incorrect threads for the material type 3. specifying tapped holes with less than five threads of engagement or stated another way, specifying tapped hold with less than one or more than three major diameters of thread depth 4. mixing unit on thread callouts (i.e inch fastener lengths on metric fasteners) 5. specifying metric threads as UNC or UNF 6. failing to specify at least one extra fastener diameter on the tap drill depth for blind threads 7. selecting threads smaller than #6 or M4 when not absolutely necessary 8. drawing unnecessary fillets and curves which cause an otherwise simple part to require a CNC 9. designing sure or D shaped holes to be made using traditional (i.e. drilling) processes 10. finishing all part surfaces 11. failing to consider room for assembly tools 12. designs a part which can be purchased OTS 13. failure to defend material choices with stress calculations corrosion or heat resistance requirements or other engineering justifications 14. design mirror image parts when a combined identical part can work in its place 15. failure to use nominal dimensions whenever possible 16. failure to make each drawing your best drawing

List 15 design mistakes which make us look like we don't know what were doing:

1. fillets 2. 2D or 3D contours

List 2 part features CNC machines can make but manual machines cannot (at least not easily):

1. fast 2. versatile 3. requires little post-weld cleanup

List 3 advantages of MIG welding:

1. it produces the strongest welds possible 2. it requires no post-weld cleanup 3. it can weld virtually any metal that is conductive

List 3 advantages of TIG welding:

1. attaching the hub to the motor 2. attaching the wheel/other power transmissions to the hub 3. transmitting the power through the hub (torque transmission)

List 3 considerations when designing motor hubs:

1. speed range 2. spindle rotation (RH rule) 3. tool clearance

List 3 things you should check when turning the milling machine spindle on:

1. more expensive 2. requires programming skill set 3. require more frequent & more costly maintenance 4. often slower for making one simple part/feature

List 4 drawbacks of CNC machining center:

1. automatically change tools 2. electric high speed probing 3. high pressure coolant 4. stiffer structures and more powerful motors

List 4 features CNC machines posses that allow increased productivity:

1. Never bring anything within 6" of the cutting zone while the spindle is running 2. Always remove parallels after clamping the workpiece in the vise 3. Always lock the quill in the uppermost position before changing tools 4. Always adjusts the spindle speed while the spindle is running 5. Always ramp gently into contact with the workpiece

List 5 rules that apply when using the milling machine:

1. type of material 2. rigidity of set-up 3. physical strength of cutter 4. cutting tool material 5. power available at spindle 6. type of finish desired

List 6 factors that influence and determine cutting speed and feed rate when milling

1. conversational programming 2. CAM programming

List and define the two common methods of programming CNC machines:

1. dimensions needed to locate every part feature 2. appropriates tolerances for every dim on dwg 3. units specification (inches, mm, angstroms,...) 4. material specification (aluminum, steel,...) 5. quantity of parts to be made 6. surface finish specs for every surface 7. appropriate hole & thread notes for every hole 8. unique part name and/or number 9. designer/drawer's name(s) (might be the same) 10. additional info about breaking sharp corners, etc.

List at least 10 items a proper detail drawing should contain

1. virtually any material can be cut 2. quality, satin finish 3. no heat in the machining process 4. environmentally responsible 5. no tool changing 6. produces minimal burrs 7. virtually any 2D shape can be cut

List seven advantages of the AWJ process

1. virtually any material can be cut 2. quality, satin finish 3. no heat in the machining process 4. environmentally responsible 5. no tool changing 6. produces minimal burrs 7. virtually any 2D shape can be cut

List seven advantages of the AWJ process 1. virtually _____ material can be cut 2. quality, _________ finish 3. no ______ in the machining process 4. environmentally _________ 5. no _______ changing 6. produces minimal _______ 7. virtually any _____ shape can be cut

1. splines 2. keyways/pin joints 3. set screws 4. press fits

List the 4 common ways to transmit torque through a hub from strongest to weakest:

1. SMAW- stick welding 2. GMAW- MIG welding 3. GTAW- TIG welding

List the formal acronym and common name for the three most common types of electric arc welding (in order of increasing quality):

1. Safety Sheets 2. Closed toed shoes 3. Long pants

List the three required items you must bring every week to your lab session and to TA office hours:

1. highly stressed tools (wrenches, ratchets, sockets) that cannot be made larger and still function 2. highly stresses internal engine components (connecting rods, pistons, valves)

List the two examples of parts mentioned in the notes/videos which are made by forging

high strength parts requiring high toughness

List the type of parts forging is good for:

1. positive mechanical engagement 2. easy to manufacture/disassemble

List two advantages of keyways and/or pin joints:

FALSE

Manufacturing time is an example of a qualitative assessment : TRUE/FALSE

FALSE

Milling is a metal cutting process used primarily for the generation of cylindrical surfaces: TRUE/FALSE

TRUE

Most lab motor fasteners are metric and should be obtained by telling the TAs what size you need: TRUE/FALSE

chuck key lathe chuck

Never leave the ______ _______ in the ______ ______ unless your hand is on it

chips

Never pull ____ off the machines using your hands; use rags instead

chuck chuck jaws

Never reach over the ______ on the lathe for any reason because of the dangerously protruding ______ _______

TRUE

Once the spindle completely stops it is still dangerous to remove cutting chips by hand because they can easily cause lacerations: TRUE/FALSE

7 4 10

Rank the following material by assigning scores between 4 (weakest) and 10 (strongest) based on their relative strengths (use 4, 7 and 10): billet metal: _____ cast metal: _______ forged metal: _____

#1 (0.228")

Select the appropriate tap drill size for tapping a 1/4-28 thread steel:

relative production time increases exponentially in relationship to desired surface finish

Summarize the relationship between relative production time and feature surface finish:

1 hp= 550 lb-ft/s

The definition of horsepower is:

TRUE

The electrode (electric conductor) used when MIG welding is consumed as the weld is made: TRUE/FALSE

1. Shorts or open toed shoes 2.Long hair which is not securely tied back 3.Jewelry on your hands or wrists 4.Loose fitting clothing

The following personal items are dangerous to wear when operating powered equipment

deep drawing/stretch forming

The lab has the following sheetmetal capabilities with the exception of:

FALSE

The lathe chuck key should be removed from the chuck after clamping the tool securely: TRUE/ FALSE

FALSE: workpiece

The lathe chuck key should be removed from the chuck after clamping the tool securely: TRUE/ FALSE

one hundred thousandths of an inch (0.100")

The max allowable material which can be removed in a single pass on the mill or lathe is:

TRUE

The speed range (HI/LOW) on the mills or lathes should be set before the machine is turned on: TRUE/FALSE

TRUE

The suitability of parts for the casting process is independent of desired quantity TRUE/FALSE

FALSE

The suitability of parts for the forging process is dependent on desired quantity TRUE/FALSE

linear

Torque vs. speed curves for electric motors are:

1. strength & thermal conductivity of material 2. depth of hole 3. presence of efficiency of cutting fluid 4. type, condition & stiffness of cutting machine 5. stiffness of workpiece, fixture and tooling 6. quality fo holes desired 7. whether you pay for replacement tools

What 7 facts affect optimum cutting speed for drilling and milling?

1. recognize the need 2. problem definition 3. gathering of info 4. concept generation 5. concept selection 6. communication 7. detailed design and analysis 8. prototype and testing 9. manufacturing 10. life cycle maintenance

What are the 10 steps of the design process

1. Drilling 2. Knurling 3. Profiling 4. Boring 5. Threading 6. Facing 7. Chamfering 8. Turning 9. Parting

What are the 9 lathe operations

1. turning 2. facing 3. profiling 4. chamfering 5. threading 6. boring 7. parting 8. drilling 9. knurling

What are the 9 lathe operations

D. all the above

What are the principal benefits on allocating individual member tasks via a work schedule? A. it allows the teams to honestly decide if it possesses adequate resources to complete the project within the allotted timeframe B. It allows the team to prepare for each lab session and work more efficiently C. it facilitates individual accountability D. all the above

water jets: 2D CNC cutting of soft materials abrasive water jets (AWJ): 2D CNC cutting of almost any material regardless of hardness

What are water jets and abrasive water jets used for?

0.250"

What does the shank diameter of a 1/4-20 fastener used in an aluminum workpiece measure?

1. faster thread specification 2. fastener head type 3. fastener length

What info is required to properly denote fasteners in assembly BOMs for this course?

size/strength of cutting edges/lips

What is the limited factor for how fast a drill or end mill can feed (or advance) thru any material?

heat generated in the cutting zone

What is the limiting factor for how fast a drill or end mill can rotate in a particular material

to prevent rapid oxidation by preventing oxygen from coming into contact with the molten metal pool

What is the purpose of flux or shielding gas?

tolerances note the allowable margin of error for each dimension; they should always be used on final part drawings because manufacturing dimensions without tolerances are useless

What is the purpose of tolerances and when should they be used?

0.0313"

What is the thread pitch for a 10-32 fastener?

adequate torquing/stretching of the bolt

What keeps a bolted joint tight?

the material/workpiece the chuck

What rotates on a lathe?

The cutting tool The spindle

What rotates on a milling machine:

1. Check speed range before turning on 2. Check tool clearance before turning on 3. Check tool direction when turning on

What rules apply when turning on the milling machine:

A. 6.60 mm (G) B. 6.30 mm (E)

What size clearance hole would you specify for a mounting bracket that uses M6x1.0 fasteners in A) aluminum, using loose tolerance or B) steel using more precise tolerances? A. B.

MIG welding automatically feeds the filler wire into the weld pool; whereas TIG welding uses a tungsten electrode to conduct the electricity and provide the heat source, and the actual filler wire is fed manually into the molten pool

Whats the primary difference between MIG and TIG welding?

TRUE

When connecting the control box to the motors for the first time you must ask a TA for help TRUE/FALSE

Directly on the spindle centerline

When operating a lathe the tool bit should typically be positioned:

after clamping the workpiece

When should the lathe chuck key be removed from the spindle:

positive mechanical engagement, & to prevent slips, called flats

When transferring torque using set-screws, why is it important to use "D" shaped shafts with small flats cut into them and what is this called?

TRUE

When wiring the control box each subsequent time you must turn off the main power before changing any wiring to prevent electric damage TRUE/FALSE

1. milling machine 2. lathe 3. welder 4. sheetmetal shear 5. sheetmetal brake 6 sheetmetal punch

Which of the 6 machines in the lab could be automated via CNC technology:

A. simple to fabricate

Which of the following is an advantage of press fits (i.e. interference fits) A. simple to fabricate B. capable of high torque transfer C. easy to assemble D. self-tightening

C. Holding in the tailstock

Which of the following is not a common work holding method on a lathe: A. Holding a chuck B. Holding between centers C. Holding in the tailstock D. Holding in a collet

holding in a vise

Which of the following is the most common work holding method on a milling machine:

choices B or D

Which of the following qualifies as an industry standard clearance hole size for a 3/8" fastener? A. 0.376" B. 0.386" C. 0.390" D. 0.397"

part numbers part quantities part descriptions unique item numbers matching the balloon numbers on the assembly drawing

Which of the following should be present in assembly BOMs created for this course?

Check speed range before turning on Check tool clearance before turning on Check tool direction when turning on

Which rules apply when turning on the milling machine:

A. Always perform tool changing above the plastic covers on the table B. Always raise the spindle to the uppermost position using the quill handle C. Always secure the quill/spindle in the uppermost position using the springs loaded lock

Which statements are true about installing/removing tools on the milling machine: A. Always perform tool changing above the plastic covers on the table B. Always raise the spindle to the uppermost position using the quill handle C. Always secure the quill/spindle in the uppermost position using the springs loaded lock D. Always place the spindle in neutral before changing tools

in order to make the best combined design

Why are separate evaluation matrices created for different parts of a design?

shoes pants

You must bring proper ______ and long ______ to office hours each week, as the sam risks exist as during normal labs

TRUE

You must provide detail drawings for all off-the-shelf parts used with your project, with the exception of fasteners; however, fasteners must appear in the assembly drawings/BOM: TRUE/FALSE

TRUE

all standard tool holders are designed to cut with the cutting point located on the centerline of the spindle ( or workpiece) TRUE/FALSE

high

always check the milling machines and lathes are in _____ range before turning them on

gently

always engage the workpiece _______ to avoid chipping the fragile cutting inserts/tools

debur

always take time to ______ each workpiece after cutting to remove the sharp edges which can injure a teammate or TA

gloves power tools

always wear _____ when working with sheetmetal, except when using _______ _______, such as bandsaws and drill presses

in cases where workpiece is not cylindrical, workpiece can be turned between centers

between centers holding

TRUE

bolt holes are always clearance holes TRUE/FALSE

T = 122 lb-in = 10.2 lb-ft

calculate the tightening torque for a grade 5, 1/4-20 fastener

T = 172 lb-in = 14.3 lb-ft

calculate the tightening torque for a grade 8, 1/4-20 fastener

T= 196.55 lb-in = 16.4 lb-ft

calculate the tightening torque for a grade 8, 1/4-28 fastener

Shaft: 0.500 Bore: 0.512 0.498 0.510 *0.010" min clearance requires min bore size of 0.510

clearance fit (assume 1/2" nominal shaft manufactured to +0.000" / -0.002" tolerance, 0.010" allowance (i.e min. clearance) and bore precision of +- 0.001"

used when smooth bar stock or workpieces must be held more accurately than can normally be achieved in a chuck

collet holding

TRUE

completed purchase orders should be brought to lab "next week" because they are required prior to cutting any material TRUE/FALSE

closeness of a measured value to a known value

define accuracy

a term for tightest possible fit (min clearance or max interference)

define allowance

the size used when the nominal size is converted to a pure decimal and from which deviations are made to produce limit dimensions

define basic size

used to cut an angle on the corner of a cylinder

define chamfering

mounts on end up spindle and grips cylindrical workpieces during operations

define chuck holding

a fit in which one part fits easily into another with a resulting clearance gap

define clearance fit

generation of surfaces oriented perpendicular tot workpiece axis

define facing

used for small amount of stock remove without much consideration of time. surface finish and feature tolerance are of much more consideration.

define finishing cuts

a fit in which one part must be forcibly fitted into another

define interference fit

the process of metal cutting for the generation of cylindrical surfaces performed on a lathe

define lathe turning

milling is the process of generating machine surfaces by removing material or stock from the workpiece by feeding into a milling cuter rotating at high speed

define milling

the size used for general description

define nominal size

clones of two or more measurements to each other

define precision

used for large amount of stock removal in short amount of time without much consideration of surface finish or feature tolerance

define roughing cuts

the total permitted variation in size for a feature. tolerance equals the difference between the upper and lower limit dimensions for a feature

define tolerance

TRUE

drill bits can only cut with their ends or lips whereas endmills can cut with both their ends and their sides TRUE/FALSE

a milling machine can be used. using an edge finder and the DRO, the edges of the workpiece can be located and a drill can be used to create the holes

explain how you would drill an accurate bolt pattern into a part using a manual machine. what type of machine would you use and what features of this machine allow it to locate holes accurately?

casting and forging processes produce much lower (worse) surface finishes and tolerances; a typical tolerance range might be 0.060"

how do the surface finish and tolerance capabilities of the casting and forging processes compare to milling and turning?

UNC: 20 UNF: 28

how many TPI do 1/4" UNC and UNF fasteners have?

TPI: 13 thread pitch: 0.077"

how many threads per inch does a 1/2" UNC fastener have? what does the thread pitch of a 1/2" UNC fastener measure?

TPI: 20 thread pitch: 0.050"

how many threads per inch does a 1/2" UNF fastener have? what does the thread pitch of a 1/2" UNF fastener measure?

.2 because .1 is taken off each side

how much is the diameter of a workpiece reduced if the cutting tool is moved 0.1" toward to the spindle's centerline and why?

total: .019" radial: .0095"

how much total and radial clearance does a free fit hole for a 5/16" bolt leave?

total: 0.007" radial: 0.0035"

how much total clearance does a close fit hole for a 1/4" bolt leave? how much radial clearance?

always select the weakest material that meets the strength requirement

how should engineers select materials to meet strength and manufacturability requirements?

TRUE

if any fasteners do not freely thread together by hand, you should stop and ask a TA before damaging expensive components TRUE/FALSE

1. heavy roughing cuts 2. when cutting stronger materials 3. to maximize tool life 4. when cutting flexible workpieces

in what 4 conditions would you use lower cutting speeds:

Shaft: 0.752 Bore: 0.741 0.750 0.742

interference fit (assume 3/4" nominal shaft manufactured to +0.002" / -0.000" tolerance, 0.010" allowance (i.e max. interference) and bore precision of +- 0.001"

1. cutting speed 2. depth of cut 3. feed rate

list 3 controllable cutting parameters that influence the metal removal rate when turning

1. turning 2. facing 3. drilling 4. chamfering

list 4 lathe operations used to produce the assigned wheel hubs in lab

1. Easy to assembly 2. Strong 3. Re-usable 4. Low density 5. Adjustable

list 5 advantages of 80-20:

drill bits are used to create a hole and reamers are used to enlarge the size of a previously drilled hole

list a functional difference between drill bits and reamers

a drill bit has 2 flutes; a reamer has more than 2

list a physical difference between drill bits and reamers

drills have a conical end while endmills have a flat end

list one physical difference between windmills and drill bits

1/2" threads in steel: 15/32" , 1.5" DEEP 1/2-20 UNF, 1.0" DEEP 3 PLACES

list the correct hole note for specifying (3) 1/2" fastener threads 1.0" deep in a steel workpiece

10 mm threads in steel: 9.2 mm THRU; M10 x 1.25 THRU; 3 PLACES

list the correct hole note for specifying (3) 10 mm threaded holes thru a steel workpiece

1/2" threads in aluminum: 27/64" THRU; 1/2-13 UNC THRU; 2 PLACES

list the correct hole note for specifying 2 holes to be drilled and tapped for 1/2" threads thru an aluminum workpiece

3/8" threads in aluminum: 0.313". 1.4" DEEP; 3/8-16 UNC, 1.0" DEEP;

list the correct hole note for specifying one 3/8" threaded hole 1" deep in aluminum workpiece

1. begin hole using a center drill 2. drill hole using a 0.157" clearance drill 3. tap hole using a tap guide, tap handle and 10-24 UNC tap

list the cutting tool sequence used to create a #10 threaded hole in an aluminum workpiece on a manual milling machine

1. complex or hollow parts 2. mass production

list the two types of parts casting is good for:

aluminum

never cut any material except _______ on the marvel bandsaw

0.201"

select the appropriate tap drill size for tapping a 1/4-20 thread in an aluminum workpiece

0.228"

select the appropriate tap drill size for tapping a 1/4-28 thread in a steel workpiece

10 mm threads in brass: 8.50, 30 DEEP; M10 x 1.5, 20 DEEP; 2 PLACES

specify (2) holes to be drilled and tapped for 10 mm threads 20 mm deep in a brass workpiece

10 mm threads in iron: 1.25, 35 DEEP; M10 x 1.25, 25 DEEP 3 PLACES

specify (3) 10mm fastener threads 25 mm deep in a an iron workpiece

1.000 +- 0.002

specify bilateral tolerance for a 1" diameter shaft manufactured to +- 0.002" tolerance

1.002 0.998

specify limit dimension/tolerance for a 1" diameter shaft manufactured to +- 0.002" tolerance

5.50 mm

specify the appropriate drill size for tapping an M6 x 0.75 thread in a steel workpiece

5.00 mm

specify the appropriate drill size for tapping an M6 x 1.0 thread in aluminum

.998 (+0.004) (-0.000) 1.002 (+0.000) (-0.004)

specify unilateral tolerance for a 1" diameter shaft manufactured to +- 0.002" tolerance

1. incorrect zero 2. jaws not normal to surface of workpiece

what are 2 mistakes that can cause dial calipers to measure incorrectly?

1. chucks 2. between centers 3. collets

what are 3 common work holding methods for lathes?

1. reaming 2. counterboring 3. countersinking 4. tapping 5. centering 6. spotfacing

what are 6 drilling related operations?

inside diameter outside diameter digital read out thousandths of an inch

what do the following abbreviations stand for? I.D. O.D. D.R.O thou

0.3750"

what does the shank diameter of a 3/8-16 fastener used in aluminum workpiece measure?

T = 0.2 x Fi x d

what is the equation used to calculate required fastener torque as a function of desired preload and bolt size?

the limiting factor is cutting tool/ workpiece machine stiffness (which must resist the cutting forces and subsequent vibrations)

what is the limiting factor for how deep to cut (per pass) with an end mill in a particular material (assuming sufficient flute length?

a center drill is used to start a hole before drilling

what is the purpose of a center drill

a clearance drill creates a clearance hole

what is the purpose of a clearance drill

a countersink allows the head of a screw or bolt to lay flush with a surface of the workpiece

what is the purpose of a countersink

a tap drill is used to create a hole that will be tapped

what is the purpose of a tap drill

a tap handle is used to turn the tap. the tap guide holds the tap handle perpendicular to the workpiece

what is the purpose of a tap handle and a tap guide?

to find zeros (edges) cylindrical and conical

what is the purpose of an edge finder and what are the two mechanical types used in the lab

lathe drilling

what is the quickest way to drill one accurate hole through the center of a cylindrical workpiece?

thread pitch = 1/TPI

what is the relationship between TPI and thread pitch?

coarse: 1.50 mm fine: 1.00 mm

what is the thread pitch for M10 coarse and fine fasteners?

+- 0.005" to +- 0.020"

what is the typical tolerance range for features machined on milling machines and lathes?

High speed steel

what material are most solid milling cutters and drills made?

coarse threads because they have smaller minor diameters which increases cross sectional thread area, resulting in high static strength and fatigue resistance in the soft material

what type of internal thread is better for soft materials and why?

drills

what typically gets clamped in the lathes tailstock

0.386 0.397

what would qualify as industry standard clearance holes for 3/8" fasteners?

A. 0.257" B. 0.266"

when mounting a part to a robot using 1/4" fasteners what size clearance hole should be specified in the mounting bracket if A) positioning accuracy is important (in which case a milling machine would be used) or B) quick manufacturing time is important (in which case a drill press would be used)

z axis

which axis is aligned with the spindle axis on the milling machines

when touching off the workpiece

It is acceptable to leave a machine running:

1. use OTS parts 2. use larger feature tolerances 3. use coarser surface finish specifications 4. use fewer finished surfaces 5. use fewer dimensions datums 6. use weaker material 7. use thru-bolted holes 8. use thru holes when reasonable/possible 9. use cone-bottomed holes 10. use nominal part dimensions 11. design parts to be smaller 12. design parts for min raw-stock removal 13. design parts to use larger cutting tools 14. design parts fewer fillets 15. design around standard cutter sizes 16. avoid mirror image (versus identical) parts 17. make great detailed part drawings

Circle the word that makes the following answers correct to reduce their part cost: 1. use OTS/ custom parts 2. use larger/smaller feature tolerances 3. use coarser/finer surface finish specifications 4. use fewer/more finished surfaces 5. use fewer/more dimension datums 6. use stronger/weaker material 7. use tapped/thru-bolted holes 8. use blind/thru holes when reasonable/possible 9. use cone-bottomed/flat-bottomed holes 10. use arbitrary/nominal part dimensions 11. design parts to be larger/smaller 12. design parts max/min raw-stock removal 13. design parts to use larger/smaller 14. design parts fewer/more fillets 15. design around custom/standard cutter sizes 16. avoid/use mirror image (versus identical) parts 17. make acceptable/great detailed part drawings

knee and column mills bed mills

Common types of milling machines include:

pouring molten metal into a mold and allowing it to cool and solidify to produce a part that is near net (i.e. final) shape

Define the casting process:

using an electric arc to heat separate pieces of similar material to be joined to a temp high enough to cause melting and coalescing

Define the electric arc welding process:

deforming heated solid metal using hammers or dies to increase material strength while maintaining good ductility and toughness

Define the forging process and explain its principal benefit:

A. review their weekly schedule and plan their individual work assignments B. review part drawings in office hours with a TA to be prepared to make the parts in lab C. complete paperwork outside their formal lab block D. print working copies of non-OTS part drawings for reference during lab E. use 80/20 wisely by selecting pre-cut pieces before cutting longer pieces to length; and only cutting the shortest over-size pieces to the necessary lengths F. bring 1:1 scale printed and trimmed sheetmetal templates to lab to expedite part fabrication G. prepare for the Tapped hole quiz so their group can use the CNC milling machine to drill and tap the holes in the face of their other wheel hub H. have a backup place in case a machine their group needs is being used by another team I. always wait for their TA to answer questions

Groups which care about their success on the course project will read the project tips posted on the website and do which of the following: A. review their weekly schedule and plan their individual work assignments B. review part drawings in office hours with a TA to be prepared to make the parts in lab C. complete paperwork outside their formal lab block D. print working copies of non-OTS part drawings for reference during lab E. use 80/20 wisely by selecting pre-cut pieces before cutting longer pieces to length; and only cutting the shortest over-size pieces to the necessary lengths F. bring 1:1 scale printed and trimmed sheetmetal templates to lab to expedite part fabrication G. prepare for the Tapped hole quiz so their group can use the CNC milling machine to drill and tap the holes in the face of their other wheel hub H. have a backup place in case a machine their group needs is being used by another team I. always wait for their TA to answer questions

16

How many threads per inch does a 3/8" UNC fastener have?

2 axis Z and X Z axis

How may axes of motion do the manual lathes have? how are the axes denoted? which axis is aligned with the spindle axis?

0.0035"

How much radial clearance does a close fit hole for a 1/4" bolt leave?

Concept A ($10): 10 Concept B ($40): 2.5

If Concept A is the cheapest, what score assignments should the two concepts received? Concept A ($10): Concept B ($40)

fine and coarse

In general, fasteners come in two varieties