Lathe Compontents And Operation Flashcards by shawn Burleigh

When using a file on the lathe why is it important to use your left hand to hold the handle?

To avoid reaching over the lathe

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What is the most typical lathe?

Engine lathe

General purpose machine that can do practically any machining jobs

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What are the types of lathe centres?

Live centres - turns with the headstock

Solid dead centres - does not turn

Half centre - allows room for tool

Revolving dead centre - spins on bearings

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What is a lathe dog for?

Transmit drive power from the spindle to a work piece.

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What is more versatile 3 Jaw or 4 jaw chucks?

4 jaw chucks can hold irregular shapes and be set up more precise.

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Tool holding systems must be?

Rigid

Adjustable

Repeatable

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What is the purpose of a steady rest?

Provide support for long work pieces

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What does a follower rest do?

Keeps work piece from

Deflecting from the cutting tool

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Turning refers to?

Rotating a workpiece and reducing its diameter with a tool.

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CS x 4 / D

CS x 320 / D

Formula for calculating spindle speed (RPM)

CS-cutting speed
D-diameter of material

as work pieces get smaller the spindle speed must be increased.

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How is feed rate measured?

Mm or inches per revolution

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Finishing requires ______ feed rate?

Between .002 and .005 inches per revolution. Choose the highest feed rate that still produces and acceptable surface finish.

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Right hand tools cut from?

Tail stock to headstock

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What is the difference between direct and indirect reading dials?

Direct dials - each line on the dial represents .001” on the diameter of the work piece

Indirect dial - each line represents .001” on the radius of the work piece. So .001 actually equals .002” of material removed

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When roughing a work piece it is important to leave _____” for finishing?

.030”

Feed rate should be as high as the cutting tool and machine can handle

Between .015 and .030

Use fewest roughing cuts as possible

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Parting off hollow workpiece that is not true will result in?

Some tips to part off?

Broken tool

part as close to chuck as possible
set cutter with as little overhand as possible
set spindle speed to half of your turning speed
if tool chatters reduce the spindle speed
never attempt to part between centres

How do you figure out cutting speed for drilling on a lathe?

Same as drill press

CS X 4 / DRILL SIZE

When using the lathe is it better to have long or short chips and why?

Short chips are better. Long chips can be dangrous

Lathe parts

Lead screw, feed rod and rack on a lathe?

Lead screw moves the carriage at a determined speed for threading

The feed rod moves the carriage at a slower rate suitable for turning.

Live centre

Driving between centres?

Fits in the headstock Must be used with a lathe dog to rotate

Old method before chucks were common to rotate work piece

Each jaw on a 4 jaw chuck moves independently. This allows a work piece to be adjusted until it runs true. What is the procedure?

1: set up headstock gear in neutral so it can be rotated
2: adjust each of the four jaws until they are at appropriate diameter
3: Insert piece and tight jaws lightly
4: place dial indicator against the workpiece at centre height. Plunger should be horizontal or vertical.
5: rotate chuck until # 1 jaw is inline with dial indicator. Set dial to 0
6: repeat this process using the #2 and 4 jaws. Spin the chuck

When is a spider attachment used?

Long tubular work piece requires a centre but the inside diameter is to large to run on a centre.

Why should you not use compressed air to clean the lathe?

Dangerous and can drive chips into places where they cannot get out.

Oiling of the ways, cross slide and taper attachment must be done when?

At the end of each day Check lubrication pots everyday Check headstock sight glass for oil level

Taper applications are :

- Cutting tool shanks - wedges - machine tool spindles - tapered mandrels and arbours - taper pins - tapered gib keys

Metric tapers are expressed by a _____ Imperial tapers are expressed by ______

Taper ratio Taper per foot TPF

Some key points about cutting speed are?

- spindle speed is set to the correct RPM to achieve the proper cutting speed. - hardness of the workpiece material and the cutting tool affect the cutting speed. The harder the workpiece the lower the cutting speed, the harder the cutting tool the higher the cutting speed. - cutting speed decreases as the workpiece gets smaller if the RPM remains constant. Spindle speed must be set higher for smaller work pieces. - use slower cutting speeds for roughing cuts and higher speeds for finishing - select slower speed to start and and increase as work allows

If you are setting depth of cut and you go past your mark what must you do to over come the backlash?

You must reverse wheel by at least a full turn and re attempt the correct setting. If you just back up to the mark it will not be accurate because of the backlash.

Finish cut gives a workpiece a smooth surface finish and and accurate size. Use the following technique for the finish cut:

1: rough workpiece to .030” 2: set the spindle speed for the maximum cutting speed for the material you are cutting 3: use highest feed rate that provides acceptable finish 4: use the cross feed dial to set a depth of cut to .015” and machine a diameter about 1/4” long 5: measure diameter with a micrometer 6: calculate how much material must be removed to produce the finished diameter. Set the Final Cut depth accordingly.

Proper depth for the centre drill?

Boring is when you machine an internal feature. Some key points are:

- Boring can only enlarge a hole, not start a tool - use a drill slightly smaller than the final bore size. - bores run perfectly true to the work piece. Drilling and reaming can only be done in nominal sizes.

Techniques to reduce chatter when boring?

- make set up as rigid as possible - mount boring bar with the least amount of overhang - if chatter occurs reduce the spinel speed and increase the feed rate until the chatter ceases. - dampen the chatter by holding a piece of wood against the boring bar - use carbide boring bits

When boring it is hard to know when to disengage the feed because you cannot see the tip of the cutter. Here are some helpful tips.

- Clamp a stop to the ways - make a small mark on the boring bar to signify the end of its travel - position a dial indicator on the ways of the lathe. So that the dial reads 0 when the carriage must be disengaged

When reaming holes use pre drill sizes smaller than 1/2 inch ream should be ______ smaller than reamer? Larger 1/2 inch and larger should be ______ smaller than reamer?

1/64 1/32 Set spindle speed to half of drilling speed and twice the feed rate Remove reamer before stoping the spindle. NEVER REVERSE ROTATION

Most dangerous operation on a lathe is?

The finishing process because your hands are so close to the rotating work piece. - hold handle of file with left hand - never use file without handle - never use file on seal or bearing fits - hold strip of emery with left hand under and right hand over - do not hold emery in the same spot - always be alert - allow work piece to cool before measuring.

Two types of knurled are

Diamond knurl Straight knurl

Knurl if should be done at?

- slow spindle speeds - .010” feed for fine knurl .020” for medium knurl, .030” for course knurl - knurling can increase diameter up to.030” diameter can be made slightly smaller before knurling if finish size is important.

When doing any filing or grinding on a lathe it is important to?

Protect the ways with plywood or cardboard. Do not use rags