machining basic concepts

8/7/2019 machining basic concepts

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Machining Lab Slide 1ME313 Metals Processing - Lab Last Modified by PAN 2/25/05

ME 313

Machining Lab

ME 313 Manufacturing Processes


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Machining Lab Slide 2ME313 Metals Processing - Lab

Purpose Introduction of the terminology and

operation of basic machine tools.

Learn the basic shop math associated with

these processes. Lathes

Drill Presses Milling Machines

Surface Grinders


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Safety Precautions

Wear safety glasses in the machine tool laboratoryat all times.

Concentrate on your present task, watch theoperation carefully and shut off the machine if in

doubt as to its operation. If a question arisesregarding machine use, ask the teaching assistantfor help, as opposed to guessing about theoperation.

When operating a machine , do not leave from theimmediate vicinity of that machine.

Do not hammer or use excess force on any part ofany machine tool.


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Safety Precautions

Immediately report any accident or hazardouscondition to your laboratory instructor, the shopsupervisor, or any other university employeeworking in the area. For first aid other than

available in the laboratory, phone Emergency 911or2-2957 on the telephone located in thelaboratory.

There will be no smoking or food allowed in the

laboratory. Long pants or sweats must be worn at all times in

the laboratory.


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Lathes n = Rotational Speed (frequency) revolutions per min, rpm

V = Cutting Speed ( Speed at Periphery of work piece) feet per min

V = n * D

V = n(rev/min) * D(in/rev) =in/min

in/min *ft/12 in = ft/12min

n = V/D where V is in ft/minD is in inches

n = 12V/D

n 4 (V/D)=


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Lathes (Cont.) f = feed, advance of tool per revolution of work pieces (in / rev)

F = feed rate (in/min)

t= time, to make the cut (min)

t = length of cuttool velocity

LF

F = f n*


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Drill Pressesn = rotational speed of the drill (rpm)

D = diameter of drill (inches)

V = cutting speed of the drill

l

l

n = 12V/D

t = length of cut

Feed rate

F = f n*


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Drill Pressesn = rotational speed of the drill (rpm)

D = diameter of drill (inches)

V = cutting speed of the drill

l

l

n = 12V/D

t = length of cut

Feed rate

l + l

F

45

l = D

xx

F = f n*


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Millingn = rotational speed of the cutter (rpm)

f = feed per tooth!!! (inches / tooth)

N = number of teeth (teeth)

F = feed rate of the table (inches / (min)

t = time to make cut in milling (min)

F = f *N* n

d

l

Rt = length of cutFeed rate

l + l

F

l


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d

l

l


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d

l


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F = f *N* n

d

l

d

R-dR

t = length of cut

Feed rate

l + l

F

l

Pythagoreans Theorem

l2 = R2(Rd) 2


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Milling Direction

Up MillingStarts with a small cut and finishes

with a large cutPushes the material away from the

cutter

Used for rough cutting

Used for deep cuts

Down/Climb MillingStarts with a large cut and finishes

with a small cutPulls the material into from the

cutter

Better surface finish

Uses less Power


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Optional Homework

1) In your lab manual there is a worksheet

which is optional

2) Solutions will be posted later this week on

the web

3) Strongly Recommended

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machining basic concepts