IME144 Midterm

accuracy

The degree to which the measured value agrees with the true value or against the standard. Instrument must be maintained by proper and regular calibration.

boring

Enlarging a hole with a SINGLE POINT CUTTING TOOL.

What lead angle do chamfer tools have?

45 degrees

chips

Material removed from a part in all machine processes.

chip load

Cross sectional thickness of a tooth that shears off with a cutter.

clearance angle

AKA relief angle. Angle of a cutting tool. Primary clearance angle prevents the cutting tool from rubbing against a workpiece. Secondary clearance angle must be large enough to clear a workpiece and allow chips to escape.

climb

A direction in milling. We prefer climb milling over conventional milling, as climb milling creates thick-to-thin chips that minimize tool overheating. Pictured is climb milling.

collet chuck

Used to secure parts. Acts as a collar around an object being held. Not to be confused with a three jaw chuck.

compound slide

The slide of a lathe that goes "diagonally." Reads in diameter.

cross slide

The slide of the lathe that goes "in" to set the depth of cut. Reads in diameter.

cutting fluids

Cool & lubricate.

materials for cutting tools

carbide, high speed steel, carbon steel. carbide is faster than high speed steel is faster than carbon steel. remember BIDEN HAS CAR (carBIDE, HS steel, CARbon steel)

depth of cut

How deep you go in a cut.

die

Used for threading in thread callouts for A (used for doing external threads). KNOW DIFFERENCE FROM TAPPING

drilling

Machining process that makes a hole

edge finder

Finds the edge of a part

end mill

Peripheral milling of a part, does work parallel to a surface of a part.

face milling

Face milling of a part, does work normal (perpendicular) to a surface of a part.

facing

On a lathe, cutting off the front of a part. Know the difference between facing and turning.

reaming

Fixed to an exact size with reamer, this process creates a hole to a tight tolerance, good for press fitting.

head stock

On a lathe, where we adjust stuff.

units for mill table feed

in/min

units for lathe feed rate

in/rev

lead angle

The angle between a cutting edge of a tool and the workpiece.

machine tools

All machining is done on machine tools.

milling

Stationary multi tooth rotating tool, you feed your part past it.

nose radius

Strengthens cutting tool, improves finish & impacts tool life.

precision

Also known as repeatability. Precision is the degree to which the instrument provides repeated measurements of the same standard.

Peripheral milling

Does work parallel to a surface of a part.

primary industry

Cultivate & exploit natural resources

secondary industry

Converts primary industry outputs into products.

tertiary industry

Service sector of economy.

primary datum

Surface of a part, it is a plane. 3 degrees of freedom constrained.

secondary datum

Line that the part is positioned against. 5 degrees of freedom constrained.

tertiary datum

Part is positioned against this point. 6 degrees of freedom constrained.

rake angles

The angle at which a cutting tool meets with a rake surface when cutting a part.

relief angle

AKA Clearance angle. Angle of a cutting tool. Primary clearance angle prevents the cutting tool from rubbing against a workpiece. Secondary clearance angle must be large enough to clear a workpiece and allow chips to escape.

rule of 10

Measuring device must be 10x more precise than specified tolerance.

right hand rule

For identifying axis of CNC coordinate system. See image attached.

RPM

revolutions per minute

sawing

A machining process using blades as a cutting tool.

shear

The act of removing chips from a part. Exposes cutting tools to stress and high temperatures.

spindle

Something that rotates on a machine

surface speed

velocity between tool & workpiece, when the surface speed is too high, the tool gets too hot

tailstock

part of lathe used for drilling, etc.

tap

Used for threading in thread callouts in B (internal threads).

thread class

number 1,2, or 3 that identifies the tightness of thread. 1 is loose, 2 is medium, 3 is tight.

thread size

size of a thread. appears first in a thread callout.

thread pitch

thread pitch = 1/TPI where TPI is threads per inch.

threads per inch

appears after thread size in thread callout.

three jaw chuck

used for holding workpieces or tools, has 3 "jaws" that get tightened to hold things in place

turning

On a lathe, cutting off the sides of a part. Know the difference from facing.

twist drill

another way to say drill

vise

part of the mill that holds parts in place

work coordinate system

origin or "0 point" for program or part

width of cut

how wide of a cut you make in a part

spot drill/center drill

creates conical hole for drill bit to drill in the right location

4 ways to specify drill size

fractional, metric, number, letter

MMC

most material condition, for shafts it is the largest number, for holes it is the smallest number

LMC

least material condition, for shafts it is the smallest number, for holes it is the largest number

if a part has negative allowance and negative clearance, what kind of fit does it have?

interference fit

if a part has negative allowance and positive clearance, what kind of fit does it have?

transition fit

if a part has positive allowance and positive clearance, what kind of fit does it have?

clearance fit

UNC

unified national coarse

UNF

unified national fine

thread angle

60 degrees

thread engagement

75%

UNEF

unified national extra fine

depth of thread

at end of thread callout, gives thread depth for good internal threads, DIFFERENT FROM TAP DRILL DEPTH

tap drill depth

distance from top to very bottom of tapped area

nodes

where we want a feature to be located

runout

how well something rotates around a central axis

feature control frame

for specifying gd&t

contour rule

when dimensioning, always dimension where the contour shows the most (the part that sticks out/is easy to measure with a caliper)

cold saw

circular saw creates precise, burr-free cuts w/ no sparks or generating heat

RPM calculation

N=4V/d

feed rate calculation

F = N x ft x t

broaching

makes holes not round. does not create holes, changes shape of holes. for example, hexagonal shapes.